Child marriage and its association with morbidity and mortality of under-5 years old children in Bangladesh.

INTRODUCTION: Child marriage is a significant social and health concern in many low- and middle-income countries (LMICs). This harmful practice violates children's rights and continues to be widespread across developing nations like Bangladesh. This study investigated the mortality trend among Bangladeshi children and the impact of child marriage on under-5 children morbidity and mortality in Bangladesh. METHODS AND MATERIALS: A sample of 8,321 children under-5 years old was analyzed using bivariate and multivariate statistical techniques collected from the recent 2017-18 BDHS data. Chi-square test and logistic regression (unadjusted and adjusted) were used to determine the influence of covariates on the target variable.
RESULTS: Results revealed that child mortality was significantly higher among children whose mothers married at an early age than their counterparts. Although the general trend in the prevalence of different childhood mortality in Bangladesh was declining gradually from 1993 to 2018, it was still high in 2018. Also, marriage after 18 years lessens likelihood of diarrhea (adjusted OR = 0.93; 95% CI: 0.76-1.16) and cough (adjusted OR = 0.91; 95% CI: 0.78-1.17) among children. Furthermore, findings reveal that likelihood of different child mortality is higher among early married women.
CONCLUSION: Immediate intervention through rigorous enforcement of policies and different programs to raise the age at marriage and by lessening socioeconomic disparities can combat the prevalence of high morbidity and mortality of under-5 years old children. Findings from this study will be helpful to accelerate strategies for achieving the Sustainable Development Goals (SDGs) related to child and maternal health by 2030.

Introduction

Child marriage is a major problem in low- and middle-income countries, as it violates human rights and disproportionately affects girls [1-3]. Unfortunately, this harmful practice remains widespread [4]. The UNICEF stated that child marriage dropped globally in the last decade; however, about 12 million girls per year even now get married before the age of 18 years [5]. The highest number of child marriages was reported in Sub-Saharan Africa (38%), followed by South Asia (30%) and Latin America (25%) [5]. For example, in Bangladesh, 59% and 22% of women were getting married before 18 and 15 years, respectively. Also, 36% of women were married before 18 years in the Dominican Republic and Brazil. In Latin America, the records are also alarming [6]. Moreover, among the Asian Muslim country, 39.5% of women had been married before the age of 18 in Pakistan [7], in 2018, approximately 11% child marriage is observed in Indonesia [8], and at least one in three young girls were married before their age of 18 years in Afghanistan [9].

Child marriage is a frequent practice in Bangladesh. Despite the advancements in recent decades, Bangladesh still has the highest percentage of child marriage in Asia and the fourth-highest rate worldwide [10]. Currently, six in every ten Bangladeshi girls are married before reaching their 18th birthday [11]. Moreover, girls who get married are often under pressure to give birth to a child early [11]. As a result, the rates of early childbearing remain high, with about 31% of Bangladeshi girls becoming mothers before they are 18 years [11]. Thus, child marriage affects them both physically and mentally and their newborns especially under-5 years children with a higher incidence of morbidity and mortality [12, 13]. Although considerable progress has been achieved in reducing under-5 child mortality, its burden remains at unacceptably excessive levels worldwide [14, 15]. About fifteen thousand children under-5 years of age died each day globally in 2017. However, the mortality of under-5 children has lessened from 12.6 million to 5.4 million from 1990 to 2017 [15].

Millennium Development Goals (MDGs) era had finished by end of 2015, during which the under-5 mortality rate decreased by 53% globally [16]. The UN Millennium Development Goal 4 (MDG-4) intends to reduce the fatality of younger children than five years by two-thirds between 1990 and 2015, but many countries, particularly in South Asia and sub-Saharan Africa, were not on track to achieve this target [17]. Although much improvement has been made in mitigating mortality among infants and children, it persists in widespread among low-middle-income countries (LMCs). Bangladesh’s government has placed a great emphasis on ending child marriage. The Sustainable Development Goal (SDG)-3 is to reduce U5MR to 25 per 1000 live births in Bangladesh. Mortality among under-5 years children than five years old is the third highest in Bangladesh among South Asian countries, followed by Afghanistan. In Bangladesh, around 31 children of age under-5 died per 1000 live births in 2017, whereas it was 34 until June 2020 [18]. Socioeconomic and environmental conditions play a substantial role in the mortality and morbidity of under-5 children [19, 20]. Children living in rural areas are approximately 1.5 times more likely to die before celebrating their fifth birthday than those living in urban areas, while children from poor-income households in LMICs remain disproportionately vulnerable to early death [6, 10].

Previous studies pointed out that child marriage is a severe problem that affects adolescent girls’ economic, social, and health status [12, 21–24]. A study pointed out that among middle-aged Indian women, early marriage was linked to worse self-rated health, a higher risk of functional limits, and chronic disorders [25], and it is more frequent in rural areas [26]. A significant percentage of women married before they became 18 years old, exposing them to early pregnancy and putting them in the ‘thin’ group (BMI below 18.5) [27]. Moreover, women married before 18 years have less chance to continue studies after marriage [28]. The age of marriage of a mother is associated with several socioeconomic and demographic variables in Bangladesh [29]. Various factors make Bangladeshi girls at risk of child marriage, such as economic pressures linked to dowry payments (money paid by the bride’s family to the groom) and thinking that marriage will provide girls with social and economic security. Additionally, teenage breastfeeding mothers receive less breast milk than adult breastfeeding mothers and likely have reduced colostrum content that produces antibodies against infectious agents [30, 31], which dramatically raises the likelihood of malnutrition [32] and a variety of other adverse health effects for their infant. Studies have already shown that low socioeconomic status, unhygienic environmental conditions, and many other factors raise the risk of different infectious diseases among newborns [20, 33, 34]. Marriage in teenagers also contributes to reduced body mass index and iron deficiency [27, 35].

Furthermore, child marriage leads to numerous adverse health consequences among early married women, such as miscarriage, stillbirth, high fertility, and maternal morbidity [13, 36]. However, evidence from previous studies found a weak relationship between child marriage and under-5 mortality as well as morbidity of children [13, 23], and a study pointed out that delivery at a young age has no effect on the child’s risk of under-five mortality [37]. The mortality rate of under-5 children is a significant public health concern in Bangladesh; however, evidence is deficient on the impact of child marriage on mortality and morbidity of children considering the most recent data. Therefore, there is a necessity to understand the influence of maternal age at marriage on childhood mortality and morbidity. The authors aimed to explore the trend of different types of child mortality using all BDHS data from 1993–2018 and evaluate the association between child marriage and different socioeconomic and demographic characteristics and finally determine the relationship between child marriage and mortality as well as morbidity among Bangladeshi children based on the most recent BDHS-2017-18 data.

Methods and materials

Data

In order to check the trend of mortality rates of children in different age groups, this study considered all available BDHS datasets (i.e. 1993–1994, 1996–1997, 2000, 2004, 2007, 2011, 2014, and 2017–18 datasets). However, for assessing the association of child marriage and determining its association with childhood morbidity and mortality, after cleaning missing data, a sample of 8,321 children under-5 years old was analyzed using bivariate and multivariate statistical techniques collected from recent 2017–18 BDHS data. The BDHS-2017-18 survey used a list of enumeration areas (EAs) of the “2011 Population and Housing Census” of the People’s Republic of Bangladesh as a sampling frame. The primary sampling unit is an EA consisting of an average of 120 households. A two-stage stratified random sampling design was used to collect this survey data. About 675 EAs were chosen in the first stage, 227 and 448 EAs from urban and rural areas respectively. However, data was impossible to collect from 3 EAs (Dhaka: one urban cluster, Rajshahi: one rural cluster, and Rangpur: one rural cluster) due to a natural disaster. Therefore, a systematic sample of 30 households was chosen from every EA in the second stage. Before starting to analyze, authors use a weighted sample to ensure a country representative sample. A detailed sampling procedure and methods of a weighted sample (mathematically adjusted) are available in the BDHS-2017/18 report [38].

Ethical approval

This study was based on an analysis of existing public domain survey data sets that are freely available online after removing all identifier information of the respondents. This survey was approved by appropriate Ethics Committees in Bangladesh and ICF Macro at Calverton in the USA. The authors took permission from Demographic and Health Surveys (DHS) program data archivist to download the dataset for this study.

Target variable

The primary target variable of this study is morbidity and mortality indicators of under-5 years children. The morbidity indicators included three variables: diarrhea, fever, and cough in the past two weeks. On the other hand, mortality indicators are under-five mortality (death of a child during their birth to 5 years of age), infant mortality (death of a child before his/her first birthday), neonatal mortality (death of a child before the first month of age), and post-neonatal mortality (death of a child between the first month and before the first birthday). Hence, for doing the analysis, all outcome variables were recoded as no = 0 and yes = 1.

Independent variables

In Bangladesh, legally, the age of marriage for women is 18 years, although in the new “Child Marriage Restraint Bill 2017”, marriages below 18 years are allowed [39]. However, in this study, child marriage is the primary predictor variable and is defined as a child marriage when the respondent’s age at first marriage was below 18 years and an adult marriage when the respondent’s age at first marriage was 18 years or more. Moreover, several demographic and socioeconomic variables are included in this study to check their association with child marriage, and in the adjusted logistic regression model, which are used as controlled variables. They are a child’s sex, age, place of residence, religion, place of delivery, delivery method, division, parental education level, mother’s BMI, and wealth index.

Statistical analysis

Bivariate and multivariate analyses were carried out to measure the association between child marriage and morbidity and mortality of children below the age of 5 years. The bivariate percentage distribution examined the discrepancies in socio-demographic characteristics and morbidity and mortality indicators according to marriage groups. The Pearson chi-square test measured the significance of child, parental demographics, and child marriage compared to adult marriage. Furthermore, associations between child marriage, morbidity, and mortality of children under-5 years of age were assessed using binary logistic regression models. Relationships between variables were quantified by calculating unadjusted and adjusted odds ratios with 95% confidence intervals. In adjusted analyses, associated variables with child marriage, i.e., age of a child (eliminated from the mortality model), child’s sex, and place of residence, religion, place of delivery, breastfeeding status, delivery by cesarean, father’s education, mother’s age, mother’s educational level, mother’s BMI, division and wealth index of a household were controlled. Furthermore, the Omnibus test is employed to check the significance of coefficients of a fitted logistic regression model. All data were weighted and analyzed using MS-Excel and SPSS Version 25.

Binary logistic regression model

We utilized binary logistic regression model as defined below: However, to calculate the crude odds ratio (COR), the logistic regression run by keeping only the targeted factor. Odds ratio (OR) in favor of outcome variable = 1 were computed for all covariates to suggest how many times a group of interest is more probable to belong to the target group compared to a reference group.

Results

Selected demographic characteristics of mothers based on the categorized variable of age at first marriage were depicted in Table 1. It is seen that about 40% of mothers got married prior to the age of 18 years whose child age is less than one year. It is also observed that most of the birth are from rural areas (45.80%), Islam religion (44.51%), Rangpur division (51.00%), and from the poorest families (56.47%) with early married women compared to others. Interestingly, findings reveal that adult married mothers gave birth through health facilities and cesarean delivery. Results also reported that illiterate and less educated mothers and less educated fathers married in their early life (<18 years). They also varied for their mother’s demographic characteristics. In addition, most adolescent mothers lived in rural areas (45.80% vs. 36.07%) compared to urban areas; women from lower-class families get married at an early age. Besides, a mother’s BMI indicates that 64.00% of mothers are obese who do not marry at an early age. Furthermore, the prevalence of child marriage is more among illiterate women than mothers who have at least secondary education [Table 1].

Table 1

Socio-economic and demographic characteristics by child marriage (<18 years) and adult marriage (> = 18 years) in Bangladesh, BDHS-2017-18.

Socio-economic and demographic characteristic	Labels	Age of women at first marriage				P-value
		<18 Years (n = 3593)		> = 18 years (n = 4728)
		n	%	n	%
Age of child (in months)	0–11	701	39.47	1075	60.53	<0.001
	12–23	723	43.04	957	56.96
	24–35	702	42.47	951	57.53
	36–47	693	43.48	901	56.52
	48–59	774	47.84	844	52.16
Sex of child	Male	1869	43.06	2471	56.94	0.082
	Female	1724	43.31	2257	56.69
Place of residence	Urban	809	36.07	1434	63.93	<0.001
	Rural	2784	45.80	3294	54.20
Religion	Muslim	3406	44.51	4246	55.49	<0.001
	Non-Muslim	187	28.0	482	72.0
Place of delivery	With Health Facility	874	34.25	1678	65.75	<0.001
	Respondent’s Home	1252	48.89	1309	51.11
Currently breastfeeding	No	1483	43.58	1920	56.42	<0.001
	Yes	2110	42.89	2809	57.11
Delivery by C-section	No	1596	46.94	1804	53.06	<0.001
	Yes	527	30.93	1177	69.07
Father’s education	No education	656	53.86	562	46.14	<0.001
	Primary	1432	50.94	1379	49.06
	Secondary and above	1448	34.72	2722	65.28
Mother’s Education	No education	317	53.37	277	46.63	<0.001
	Primary	1261	53.36	1102	46.64
	Secondary and above	2015	37.57	3348	62.43
Mother’s BMI	Thin (<18.5)	559	49.38	573	50.62	<0.001
	Normal (18.5–24.9)	2210	45.30	2669	54.70
	Obese (25 and more)	779	36.00	1386	64.00
Division	Barisal	210	45.55	251	54.45	<0.001
	Chittagong	739	42.30	1008	57.00
	Dhaka	791	37.47	1320	62.53
	Khulna	372	48.44	396	51.56
	Mymensingh	337	47.80	368	52.20
	Rajshahi	491	50.57	480	49.43
	Rangpur	448	51.00	480	49.00
	Sylhet	205	30.19	474	69.81
Wealth index	Poorest	1008	56.47	777	43.53	<0.001
	Poorer	836	49.41	856	50.59
	Middle	683	43.53	886	56.47
	Richer	663	40.06	992	59.94
	Richest	404	24.91	1218	75.09

The line graph illustrates different mortality rates for children in Bangladesh between 1993 and 2018. The prevalence of child mortality of all categories declined gradually throughout the study. Under-5 child mortality declined from 134 to 45 per 1,000 live births between 1993 and 2018. A similar trend is observed for infant mortality. Moreover, the infant mortality rate was 88 in 1993, then gradually decreased to 38 per 1,000 live births over the next two decades. However, in 2014 and 2018, it remains unchanged. The neonatal mortality rate also declined from 52 to 30 between 1993 and 2018. A declined scenario was also noted for post-neonatal mortality as it decreased by almost 5-folds from 1993 to 2018. Although mortality rates have been declining over the last decade, it has been slow compared to the first decade in the study period. Except for post-neonatal mortality, all are still high (45, 38, and 30 per 1,000 live births) in 2018 ().

Table 2 depicts the prevalence of morbidity and mortality of under-5 years’ children of married women aged between 15 to 49 years. Results revealed that among children under-5 years of age who had been affected by diarrhea in the past 2 weeks of conducting the survey, 57.58% of children who were born to early married women (<18 years old) (p-value = 0.08). About 45.13% of children of early married women had been suffered from fever in the past 2-weeks (p-value = 0.01). About 55.82% of children who were born to women who got married at an early age had experienced cough in the past 2-weeks of the survey (p-value = 0.02). Additionally, under-5 mortality (0–5 years old) was significantly prevalent among the children born to early married women (65.19%) compared to adult married women. The prevalence of infant mortality (before one year) was 62.56% for early married women and 37.44% for their counterparts. Furthermore, among children whose mothers married at an early age, 61.04% died before their first month of life compared to 38.96% died who were born to adult married women. However, in the case of post-neonatal mortality, we observe adverse results, i.e., prevalence is lower among children born of early married women (32.06%) than adult married women [Table 2].

Table 2

Prevalence of morbidity and mortality of under-5 years children by child marriage (<18 years) and adult marriage (> = 18 years) in Bangladesh, BDHS-2017/18.

Morbidity and Mortality Indicators	Labels	Age of women at first marriage				P-value
		<18 Years		> = 18 years
		n	%	n	%
Morbidity indicators
Had diarrhea in last 2-weeks	No	4501	56.77	3426	43.23	0.08
	Yes	227	57.58	167	42.42
Had fever in last 2-weeks	No	2344	42.23	3214	57.77	0.01
	Yes	1249	45.13	1514	54.87
Had cough in last 2-weeks	No	3059	57.36	2268	42.64	0.02
	Yes	1669	55.82	1325	44.18
Mortality indicators
Under-5 mortality	No	2142	62.94	1261	37.06	0.03
	Yes	367	65.19	196	34.81
Infant mortality	No	572	65.82	297	34.18	0.08
	Yes	1938	62.56	1160	37.44
Neonatal mortality	No	1034	66.80	514	33.20	<0.001
	Yes	1476	61.04	942	38.96
Post-neonatal mortality	No	1239	37.71	2047	62.29	0.01
	Yes	218	32.06	462	67.94

Age of a child has been identified as a significant determinant of diarrhea. Therefore, to see a clear picture of the prevalence of diarrhea among under-5 children, Fig 2 illustrates diarrhea prevalence by age of a child and whether their mothers married as early age (<18 years old) or not. It is seen that the highest number of children suffer from diarrhea between the age of 12 to 23 months. However, after two years of age, the prevalence of diarrhea is declining for children whose mothers were getting married at an early age or not (Fig 2). Moreover, the prevalence of different child morbidity and mortality indicators by selected background characteristics are presented in (S1 Table). Results depict that child morbidity and mortality indicators vary across a child’s characteristics, parental characteristics, and geographical regions.

Fig 2

Prevalence of diarrhea by child’s age and status of marriage in Bangladesh, BDHS-2017/18.

The associations between child marriage and morbidity and mortality of under-5 children are presented in Table 3. The p-value of the Omnibus test is employed to check the significance of coefficients of a fitted logistic regression model, i.e., modelling between morbidity indicators and child marriage is less than 0.001, which concludes that we may reject the null hypothesis that intercept and all coefficients are zero. Also, results of the classification table demonstrated that about 95.2%, 66.8%, and 64.1% of observations are classified accurately by fitted model for diarrhea, fever, and cough, respectively. Similarly, in the case of the fitted model for different child mortality and child marriage, results indicate that we may reject the null hypothesis that all coefficients are zero at 5% level of significance since all p-values are less than 0.001. Findings also illustrated that the classification accuracy for under-5, infant, neonatal and post-neonatal mortality are 86.2%, 78.5%, 61.5% and 83% respectively [Table 3].

Table 3

Impact of child marriage (< 18 years old) on morbidity and mortality of under-5 children in Bangladesh; BDHS-2017-18.

Characteristics	COR (95% CI)	AOR (95% CI)	Model validation
Morbidity indicators
Had diarrhea in last 2-weeks a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	0.97 (0.79–1.18)*	0.93 (0.76–1.16)*	Classification percentage: 95.2
Had fever in last 2-weeks a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	1.12 (1.03–1.23)	1.05 (1.01–1.22)*	Classification percentage: 66.8
Had cough in last 2-weeks a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	0.86 (0.72–1.16)*	0.91 (0.78–1.17)*	Classification percentage: 64.1
Mortality indicators
Under-5 mortality a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	0.92 (0.84–1.33)*	0.79 (0.62–1.02)**	Classification percentage: 86.2
Infant mortality a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	0.82 (0.74–1.02)*	0.89 (0.67–1.13)*	Classification percentage: 78.5
Neonatal mortality a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	0.78 (0.68–0.89)***	0.84 (0.72–0.97)**	Classification percentage: 61.5
Post neonatal mortality a
Child marriage (Ref.)			Omnibus Tests (p-value): <0.001
Adult marriage	1.12 (1.08–1.53)**	1.13 (0.86–1.20)**	Classification percentage: 83.0

COR = Crude Odds ratio; AOR = Adjusted Odds ratio; CI = confidence interval; *p < 0.05, **p < 0.01, ***p < 0.001; aAdjusted analyses controlled for age of the child, sex of the child, place of residence, religion, place of delivery, breastfeeding status, delivery by caesarean, father’s education, maternal education, maternal BMI, division and wealth index; Ref.: Reference category.

Results revealed that children of adult married (> = 18 years old) women were less vulnerable to have diarrhea (COR: 0.97, 95% CI: 0.79–1.18) and cough (COR: 0.86, 95% CI: 0.72–1.16) except fever (COR: 1.12, 95% CI: 1.01–1.22) though it is insignificant than those children whose mother were married at an early age (<18 years old). The association also remained significant for diarrhea (AOR: 0.93, 95% CI: 0.76–1.16), cough (AOR: 0.91, 95% CI: 0.78–1.17), and fever (AOR: 1.05, 95% CI: 1.01–1.22) after controlling relevant demographic characteristics in logistic regression analysis. However, there is a 5% more chance to suffer from the fever of children of adult married women than their counterparts. Children born to women who were married at age of 18 years and later were approximately 21% less likely to under-5 child mortality (AOR: 0.79, 95% CI: 0.62–1.02) than children whose mothers were married early age. The relationship between maternal adolescent motherhood and neonatal mortality was also significant in adjusted analysis. However, in the case of post-neonatal mortality, a child from adult married women have 13% higher chance of post-neonatal mortality than a child from early married women. Findings reveal that there is 11% higher likelihood of infant mortality among children whose mothers married early than adult married women after adjusting some relevant demographic characteristics [Table 3]. Furthermore, detailed results of logistic regression for each model are summarized in a [S2 Table].

Discussion

Child marriage is a frequent social practice in Bangladesh, and its high prevalence contributes to early pregnancy, which poses a long-term danger to younger mothers and the wellbeing of newborns [40, 41]. Initially, authors find the association of different socio-economic factors with child marriage and the effect of covariates are adjusted in logistic regression. Findings reveal that the prevalence is significantly varied by considering age and sex of a child, parental education, wealth index, residence. In Bangladesh, practicing of child marriage is significantly higher among low-income families because it is assumed that girls are specially born to run households. Therefore, it is generally thought that sending females for higher studies seems to create an economic burden. In rural areas, most households can afford to send at most two children to school, and in such cases, sons receive preference due to their role as to carry the name and family title of father and will assure parent’s future [42, 43]. Nowadays, educated parents are more concerned about women’s empowerment, and higher educated parents will have a higher educated child because higher educated parents are financially rich, and they make enormous efforts to confirm their children’s academic success [43-45]. Therefore, the regional difference in educational, socio-cultural, and financial status are key factors of practicing child marriage [28].

Findings presented in Fig 1 illustrate that infant, neonatal, post-neonatal, and under-5 years of child mortality rates in Bangladesh had a declining rate over the study period. This study investigated the relationship of child marriage with morbidity and mortality of under-5 years of age children in Bangladesh by exploring a trend of child mortality. This study revealed that child marriage was significantly associated with morbidity and mortality of children under-5 years of age even after adjusting socio-demographic and other covariates. The findings of this study are somewhat different from previous studies in India and Pakistan, which showed child marriage weakly correlated with under-5 years child morbidity and mortality but no correlation identified in adjusted models [13, 23, 24].

Fig 1

Trend of mortality rates of different groups of children from 1993 to 2018, Bangladesh.

Considerable evidence suggests that child marriage has significant adverse consequences detrimental to girls, their children, and their communities. A child born to a teenage mother is twice as likely to die before the first day of her life than a mother of aged twenties [41, 46]. Evidence from earlier studies has also demonstrated that child marriage raises the incidence of infectious diseases for their newborns and thereby enhances the susceptibility of infant, child, neonatal, and post-neonatal mortality [47, 48]. Even though these children live, they are more vulnerable to low birth weight, premature birth and mortality, than children born to older mothers [49]. Prior studies in Bangladesh revealed that neonates and children with younger mothers have a greater mortality risk than older mothers [40, 41]. Plausible explanations for this could be the early age of mothers correlated with bad health-seeking behavior [50] and mother’s experience with optimum infant feeding [51]. Unlikely, other research found no significant association between teenage mothers and child morbidity, such as diarrhea and fever [12, 23]. Surprisingly, this research also demonstrated that children of adult married women were significantly less vulnerable to diarrhea (AOR: 0.93) and cough (AOR: 0.91) than children born to child married women. Child marriage in Bangladesh is possibly a proxy for maternal limitations that endanger young children’s wellbeing, which raises the probability that young mothers and their related social and economic shortcomings contribute to poor child health outcomes [52, 53]. Our results illustrate the importance of delaying childbirth for those married under the age of 18 years and indicate that the younger mother’s socioeconomic and cultural disadvantages can contribute to poor health outcomes for children.

Over the last decades, Bangladesh has undergone a substantial decline in child mortality [54], which was helpful to gain the MDG-4 target. Nevertheless, mortality among under-5 years of old children and neonatal mortality need to be lessened for achieving the Sustainable Development Goals (SDGs), which are intended to reduce neonatal and under-five mortality rates to at least as low as 12 and 25 deaths per 1,000 live births respectively [18]. Reducing the prevalence of child marriage would be beneficial to achieve targeted SDG goals.

Strengths and limitations

The strength of this study is the novelty of the work and considering the most recent country representative BDHS-2017/18 dataset. This analysis is cross-sectional, and causal inference is not possible; but, since child marriage occurred before the measured results, ordering of this exposure could be presumed compared to child health incidents. The examined results are based on self-reporting and are thus vulnerable to variation in memory and social desirability. Similarly, multiple socioeconomic and environmental factors in this setting may contribute to the incidence of diarrhea and related mortality that was beyond track in the regression model. This included only specific infant and maternal demographics in multivariate analyses. We have also restricted our sample to births in the previous five years for the ever married 15–49 years old women. Lastly, results are unique to young women in Bangladesh and cannot be generalized within Bangladesh to other regional contexts. Future research would be carried out to find the effect of child marriages on child health outcomes incorporating other factors like child’s BMI, immunization status, spatial variation by utilizing PSM methods and Matching techniques to get a clear comparison picture of the two groups studies.

Conclusion

Most child-married women are from rural areas, follow the Islam religion, live in the Rangpur division, and come from the poorest families. Findings reveal that both illiterate and less-educated men and women were getting married at an early age. Although rates of several categories of child mortality have decreased dramatically over the last three decades, all are still high (45, 38, and 30 per 1,000 live births) in 2018. This study also revealed that child marriage of women marginally influences mortality and morbidity of under-5 year’s children in Bangladesh. A variety of socio-demographic and cultural differences are significant predictors of this issue. However, a longitudinal study is required to recognize the impact of child marriage on the health outcomes of children. Authors suggest that the government of Bangladesh should try to provide adequate assistance and structural modifications to eradicate child marriage that will benefit girls along with their families, community, and society. Authors also recommend an upsurge in age at women’s marriage by rigorous enforcement of child marriage laws. Furthermore, participation in education and empowerment of younger women may help to minimize child morbidity and mortality rates. Finally, the need for tailored intervention to sustenance children born to mothers married at an early age is crucial which can reduce morbidity and mortality among under-5 years of age children in Bangladesh, which will be helpful to accelerate strategies for achieving Sustainable Development Goals (SDGs) related to child and maternal health by 2030.

Prevalence of child morbidity and mortality Indicators by Socio-economic and Demographic Characteristics, BDHS-2017/18.

(DOCX)

Click here for additional data file.

Results of logistic regression, BDHS-2017/18.

(DOCX)

Click here for additional data file.

16 Sep 2021

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Additional Editor Comments (if provided):

Although the research question of this study is very important, but in its current form it doesn't suits for publication in PLOS One. The paper is less likely receive favourable opinion from the reviewers. The analytical plan and tools are very weak and doesn't support the research question. Thus, I recommend authors to revise and resubmit to PLOS One or any other journal. Moreover, dont attempt to measure impact or causation from a cross-sectional data. Try to use PSM to address the adverse affect of child marriages on child health outcomes. Consult following papers for methods and framework of analyses.

Vikram, Kriti. "Early marriage and health among women at midlife: Evidence from India." Journal of Marriage and Family (2021).

Goli S, Rammohan A, Singh D. The Effect of Early Marriages and Early Childbearing on Women's Nutritional Status in India. Matern Child Health J. 2015 Aug;19(8):1864-80. doi: 10.1007/s10995-015-1700-7. PMID: 25656721.

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19 Sep 2021

Dear Srinivas Goli, Ph.D.

Academic Editor

PLOS ONE

We would like to sincerely thank the Academic Editor for your valuable comments. We have considered all comments and then thoroughly revised and formatted the manuscript. A detailed response to each particular comment is provided in the tables as follows.

Thank you very much for your valuable comment and feedback. We believe that it will be helpful to improve the quality of the manuscript.

We have cited the suggested papers in our manuscript.

Thanks for your suggesting to use PSM for finding the adverse effect of child marriages on child health outcomes. However, in light of the existing literature, it is found that there are several manuscript used the logistic regression to identify the association between child marriage and child health outcome. Therefore, we think this would be a potential topic for future research. All revised texts are in “red” color. Page 1, 4, 7-9, 14-15, 18-19.

Thanks. We ensure you that we follow the journal guidelines for formatting purpose.

Thank you very much for your valuable comment and suggestions that help improve the manuscript's quality. We thoroughly checked the grammatical issues and also check by Grammarly software.

We upload the required files following the guidelines provided. All revised texts are in “red” color. Page 1-15.

Thank you very much. The authors received no specific funding for this work. We add this statement in the manuscript and cover letter. Revised texts are in red color. Page: 15.

Thanks. We move the ethical statement from the end of the manuscript to the Methods section. The revised texts are in red color. Page: 5.

Thanks. We have removed Figure 2 from our manuscript. Page: 12.

In conclusion, the revised version of the manuscript has been produced as per the review outcomes. So, we hope that you would be happy to see this greatly improved version. Once again, we would like to thank you all for your dedication, professional services and cooperation.

Submitted filename: Response to Reviewers.docx

Click here for additional data file.

25 Nov 2021

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

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If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

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We look forward to receiving your revised manuscript.

Kind regards,

Srinivas Goli, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments:

Considering my own reading of the paper and all four reviewers observations, I am going with a decision of Reject and Resubmit.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: (No Response)

Reviewer #2: All comments have been addressed

Reviewer #3: (No Response)

Reviewer #4: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Partly

Reviewer #3: Yes

Reviewer #4: Partly

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: No

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: No

Reviewer #4: No

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: I have some minor suggestions. Please find them below:

1. Line 109- replace 'published BDHS datasets' with some other relevant word. 'Published' is not a correct word here.

2. In table 1 (and wherever relevant): place 'in month' in bracket after age of child. It should be- age of child (In months). Table 1 first demographic characteristic.

3. Please confirm the p-value for teh sex of the child in table 1.

4. Authors may provide CIs for crosstabs also. This would increase the robustness of the study findings.

5. Consider changing post-natal mortality to post neonatal mortality.

6. Furthermore, women who particularly lived in rural areas, are not permitted to visit a health

care facilities for their own as well as their children’s health [54,55]. In above sentence, authors cited quite old references. Either update the reference or consider omitting the sentence as the current situation may be different.

7. According to the findings of the study, illiterate and undereducated mothers and fathers married in their early age. In the sentence, consider replacing 'mothers and fathers' as when they married off, they were men and women and not mothers and fathers.

Reviewer #2: Title: Child marriage and its association with morbidity and mortality of under-5 years old

children in Bangladesh

Authors: Md. Moyazzem Hossain, Rajon Banik, Faruq Abdulla, Sabina Yeasmin and Azizur

Rahman

Thank you for the chance to review the paper. It is an interesting paper that focuses on Child marriage and its association with child morbidity and mortality pattern in Bangladesh. Overall, the paper has explored a vital area; however, for strengthening the paper, here I have outlined my concerns and suggestions.

• Writing “early married women” Instead of “child married women” sounds more appropriate. I would suggest to rewrite using the suggested terms. (Found in lines – 36, 184, 213, 214, 217, 219, 223)

• The sentence “Girls who get married are often under pressure to give birth to a child early”- in line number 59 needs reference.

• The statement in lines 81-84 consists factual information. Please provide reference supporting the information.

• The statement in lines 270-271 mention about “map”, however the map has been removed by the authors. Please modify the statement.

• The authors are suggested to incorporate “Child’s BMI” and “Child’s Immunization status” as controlled variable in the binary logistic regression model, since these variables can affect the morbidity and mortality of children under age 5. All these variables can be created using BDHS dataset.

• Reading discussion of this, I have found that most of the findings are found consistent with previous studies. Then the authors should clarify the contribution of this study to academia. More focus should be given to the unique findings first and then others.

• Moreover, I would suggest to use PSM technique rather than logistic regression. The PSM method can strengthen the analysis and can stand as more appropriate for this study.

Reviewer #3: Comments

The central theme and the issue discussed here in the paper is significant and holds relevance to the country since as stated by the authors, in Bangladesh, 59% and 22% of women get married before the age of 18 and 15 years, respectively. And with about 31% of Bangladeshi girls becoming mothers before they are 18 years, this is a serious issue and should be studied thoroughly, As such, the analysis is timely and of potential value for policymakers. Appreciate the authors for taking such a relevant issue to study. This would definitely lead to an increase in the knowledge base in this domain. However, some problems with the writing of this paper should be addressed before the manuscript is accepted for publication.

There are some more revisions required in writing. Some of the errors which might need revision are-

Line 32 Was declined- was declining

Line 33- is still high- was still high

Line 47- that affect- which in turn affect

Line 132- the authors take permission- the authors took permission

Line 189- urban areas, women who are from lower-class families get married at an early age.

Line 198 - categories was declined- categories declined

Line 199- mortality was declined- mortality declined

Line 204- was decreased- decreased

Line 215-216- moreover has been used repeatedly. The sentence should be modified.

Line 353- According to the findings of the study, illiterate and undereducated mothers and fathers married at their early age. -Rephrase the sentence.

Overall, English write-up needs to be checked carefully in the whole manuscript, sometimes some errors are overlooked by software. There should be a flow in the usage of tenses. The methodology is fine and easy to understand but it is basic, the authors could have used some more sophisticated methodology to compare and get a clear comparison picture of the two groups studies. Some Matching techniques can be used which would make the study unique and completely different from the already done work. Further, such a methodology would also help in understanding a few new dynamics of the factors contributing to child marriage and child mortality in Bangladesh.

Incorporating these few changes, this study would be a valuable resource for future studies in this field.

Reviewer #4: This article is based on cross-sectional data from a cross-sectional population survey with 8321 children under the age of five in Bangladesh. The first aim was to estimate the births to women born into child married and adult married women in Bangladesh by socioeconomic characteristics, defined as women age at first birth <18 years and >18 years. The second objective relates to the prevalence of morbidities and mortalities under 5 years’ children by child marriage and adult marriage women. The author looks at three morbidities in the last two weeks, such as diarrhea, fever, and cough, as well as four mortality indicators, including infant mortality, neonatal mortality, and post-neonatal mortality. The findings revealed that child mortality among adult married women was considerably lower. However, there are certainly major issues that must be addressed.

Introduction

Unfortunately, the language is difficult to understand. To improve the text's understandability, flow, and readability, I recommend the authors engage with a translator, writing coach, or copyeditor. Even, I can see, the editor highlighted the same concern about the writing quality, however, it hasn't significantly improved.

Results

The author has written the age at first marriage in lines 180 and 181, but the table indicates the age of the women at first birth, which may confuse the reader. Please correct the terminology. "43% of children's mothers got married before the age of 18 years”, the authors wrote again on line 181, but the table author has taken the children age groups but do not specify in the above statement. In line number 188, the authors repeated the findings from line number 182, which are related to the 45.8% of births to mothers under the age of 18 years. The author has stated "obesity is lower among women who do not marry at a young age compared to their counterparts" on line 189, however the author's unit of analysis is children, therefore please correct this. There are numerous typos in Table 1, so kindly update these names. Another observation is that the age of the child in month variables labels are not properly specified, such as 36-47 near interval, and the last label started again 47-59; please explain why. The author wrote that the COR for fever is 1.05 in line 249, however, the table shows that it is 1.12. There is an incomplete sentence in line 253 of the manuscript. The authors have written that the OR is 0.79 and that the 20% more likely is shown in line 256; please correct this sentence. The authors used early married women in line 260, but married before their 18 years’ age in line 255, which would confuse the reader. Please use the same variables names that are used in the tables.

Some general comments regarding figures and graphs

Figure 1 is not a standard graph; please make a standard line graph.

Table 2: The P-value was misdefined by the authors.

Table 3: The author applied the Omnibus test, however the methodology section did not mention it.

Discussion

"Children of women married as a child were significantly more vulnerable to diarrhea and fever than children born to married women as adults," the authors wrote in line 288, I assume that they were referring to the adjusted odds ratio. However, the result in table no 3 is completely different.

The author has written in lines 303, 304, and 305 that this research showed that infant, neonatal, post neonatal, and under -5 years of child mortality in Bangladesh increased from 1993 to 2014 over the years and the rate is diminishing steadily over time, yet these are unclear and perplexing.

The author writes in line 311 that "a substantial number of social-demographic variables have a significant effect on child married in Bangladesh," however I don't find any evidence that the authors looked into child marriage or that the author's unit of analysis were child married women.

The last paragraph of the discussion, in lines 328-329, is not the authors' results, although they do not provide any references.

I probably stick to a simple structure and using precise terms. It is necessary to improve the discussion. The authors are confused by the unit of analysis in general throughout the article. Many grammatical errors remain.

**********

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

8 Dec 2021

Dear Editor,

We sincerely thank the Academic Editor and four anonymous reviewers for their valuable comments. We have considered all comments and then thoroughly revised and formatted the manuscript. A detailed response to each comment is attached with this submission.

We also hope that you will be happy to see this greatly improved version. Once again, we would like to thank you all for your dedication, professional services and cooperation.

Thanks in advance.

Hossain

Submitted filename: Response to Reviewers.pdf

Click here for additional data file.

26 Dec 2021

A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Srinivas Goli, Ph.D.

Academic Editor

PLOS ONE

Journal Requirements:

Additional Editor Comments (if provided):

Reviewers still not pleased  with the revisions. Considering their opinion and my own reading, I am recommending a major revision for this manuscript. This will be a last chance for you to incorporate the reviewers suggestions. 

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: All comments have been addressed

Reviewer #4: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Partly

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: I Don't Know

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #3: No

Reviewer #4: No

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The authors have carried out the revision as suggested and that has improved the manuscript to an extent. I still have some doubts and suggestions regarding the manuscript, which are as follows:

1. The image in figure 1 does not seem to be matching with the text in the manuscript. The authors can please clarify this. For ex: in text, it was written "Moreover, the infant mortality rate was 88 in 1993, then gradually decreased to 38 per 1,000 live births over the next two decades. " However, the figure is showing different numbers. Please confirm, if I am wrong in analyzing the figure. A similar mismatch is there in the text at other places too for figure 1.

2. For table 2, if authors could segregate the prevalence of diarrhea by age of the children, it would present a clear picture. Studies have noted the age of the children as an important factor in the prevalence of diarrhea. so presenting diarrhea among children of various ages by women's age at marriage.

3. Please confirm that for table 3, what is the reference category? In table 2, authors have taken two categories for married women - women who married below 18 years and women who married at 18 and above 18 years. But in table 3, authors have taken women as above 18 years old, thereby leaving women who were 18 years old. Why so discrepancy?

4. Table 1 is providing the differences by age at marriage of the women. I would also suggest to add a table (may be as supplementary) that provides within group differences. For ex: it would be interesting to see the differences between sex, religion, and other covariates. currently, the total adds up for women age grouyp. I want that to be added for covariate.

Reviewer #3: There have been various necessary changes which are praiseworthy. However, a little English revision still needs to be done. After which the paper is good to publish.

Some of the places where revision is needed-

Line 46 which in turn affecting

Line 49 marriages has happened

Line 110 there is necessary – there is a necessity

Line 156-They are a – should be –‘which are’

Line 160- The bivariate and multivariate - Bivariate and multivariate

Line 165- child marriage and morbidity and mortality- child marriage, morbidity and mortality

178- variable that assign- Variable that assigns

Paper should be thoroughly read and other errors should be rectified to standard English.

Usage of article “The” in the sentences should be checked and only put where ever necessary.

Mother’s BMI has been divided in to- Thin, Normal and Obese, does this include overweight and obese too? There should be some mention of how BMI is categorised.

Reviewer #4: I would like to make a couple of minor suggestions. They are listed below:

The authors have incorporated the most of the previous comments into the manuscript.

But, some additional comments authors should be considered.

Introduction

In line numbers 52 and 53, the authors describe the prevalence of child marriage in the Dominican Republic and Brazil, how it is justified, and whether or not both countries have the same socioeconomic conditions as Bangladesh. It would be better to compare the Dominican Republic and Brazil to Pakistan and Indonesia, where the majority of the population adheres to the Muslim religion.

Line 89, the authors have written the putting them in the thin group, what is the thin group, the sentence is unclear.

Results

Still, Figure is not a conventional graph; please see the other published paper graphs.

In the result section, the authors have written that the COR but written Adjusted AOR, the author can write same AOR instead of adjusted AOR.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #3: No

Reviewer #4: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

1 Jan 2022

Dear Srinivas Goli, Ph.D.

Academic Editor

PLOS ONE

Thank you very much for providing another chance and valuable comment and feedback to improve the quality as well as suitability for publication of our manuscript. All revised texts are in “red” color.

All necessary files are uploaded to the journal system.

Response to Reviewer 1 comments:

1. Thank you very much for carefully checking the manuscript. Actually, the Y-axis level was wrong in Figure 1. Now, Figure 1 is corrected. Page: 9

2. Thank you very much. According to your suggestion, we revise the manuscript and add a figure (Figure 2) for presenting the prevalence of diarrhea among children of various ages by women's age at marriage. Page: 10-11

3. Thanks. We revise the texts. Page: 12

4. Thanks. We add a Supplementary Table (S1 Table) in the revised manuscript. S1 Table

Response to Reviewer 3 comments:

Thank you very much again for carefully checking the manuscript and your feedback. It will help to improve the quality of the manuscript.

Page: 1, 7, 9, 10

Thanks. We have checked and fixed the grammatical issues. Article “The” has been removed from some places. Page: 2-16

Thanks, we appreciate your concern. In Table 1, we add the range of BMI for making categories. Page: 8

Response to Reviewer 4 comments:

Thank you very much for your appreciation and insightful feedback. We believe that your comments help to improve the quality of the manuscript.

We revise the manuscript considering the information of Muslim countries like Pakistan, Indonesia, and Afghanistan.

We add the BMI range for the “thin” group in line 89. Page: 2, 3,

Thanks for carefully checking the manuscript. We replace Figure 1 and incorporate all your suggestions in the revised version of the manuscript. Page: 9, 11-13

In conclusion, the revised version of the manuscript has been produced as per the review outcomes. So, we hope that you will be happy to see this greatly improved version. Once again, we would like to thank you all for your dedication, professional services, and cooperation.

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6 Jan 2022

6 Jan 2022

Dear Srinivas Goli, Ph.D.

Academic Editor

PLOS ONE

Thank you very much for providing another chance and valuable comment and feedback to improve the quality as well as suitability for publication of our manuscript.

We add a supplementary Table (S2 Table) to summarize the results of logistic regression.

We replace “demographic factors” by “Socio-economic and demographic characteristics” in Tables.

The equation of logistic regression is revised as per feedback.

All revised texts are in “red” color. Page: 6-8, 13, S1 Table, S2 Table

All necessary files are uploaded to the journal system.

We would like to thank you all for your dedication, professional services, and cooperation.

Best Regards,

Hossain

Submitted filename: Response to Reviewers.pdf

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10 Jan 2022

Child marriage and its association with morbidity and mortality of under-5 years old children in Bangladesh

PONE-D-21-24855R4

Dear Dr. Hossain,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Srinivas Goli, Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Now, this paper is ready for publication. I am recommending it.

Reviewers' comments:

31 Jan 2022

PONE-D-21-24855R4

Child marriage and its association with morbidity and mortality of under-5 years old children in Bangladesh

Dear Dr. Hossain:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

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Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Srinivas Goli

Academic Editor

PLOS ONE