Maternal and socio-demographic determinants of low birth weight (LBW): A community-based study in a rural block of Assam.

BACKGROUND AND RATIONALE: Low birth weight (LBW) leads to high neonatal and infant deaths. There is also high prevalence of childhood morbidities and mortalities that are consequences of LBW.
OBJECTIVES: To find out the prevalence of LBW babies among the study population and to find out the effect of certain maternal and socio-demographic characteristics on birth weight.
MATERIALS AND METHODS: This cross-sectional study was carried out in a rural block of Assam. Cluster sampling was done to choose 30 villages and 15 infants were selected randomly from each village to get a sample size of 450.
RESULTS: Prevalence of LBW was found to be 21.8%. Percentage of LBW babies was more among the teenage mothers (36%) and primipara mothers (27%). Maternal anemia [odds ratio (OR) 1.93; confidence interval (CI) 1.3-2.9], short interpregnancy interval (OR 3.93; CI 2.16-7.13), and teenage pregnancy (OR 3.93; CI 2.16-6.45) were found to be the independent risk factors associated with LBW of the babies. DISCUSSION: The study findings indicated the high prevalence of LBW babies in rural areas of Assam and illiterate teenage mothers, grand multipara, anemic mothers, and short interpregnancy intervals were the important risk factors for LBW.

Background and Rationale

Assam has the highest maternal death rate in India,[1] and has a high prevalence of both anemia and malnutrition,[2] which are directly reflected in birth weight of new born. The annual health survey (2012-2013) revealed that 23.3% of newborns in Assam are low birth weight (LBW).[3] There is insufficient data on factors that influence LBW in rural areas. Therefore, the present study was undertaken in a rural block of Assam with the objectives of finding out the prevalence of LBW babies among the study population and to find out the effect of selected maternal and socio-demographic characteristics on birth weight.

Methods

The present study was a cross-sectional study conducted in Boko Bangaon Developmental Block area of Kamrup district Assam. This block is situated around 80 km west of Guwahati city and the block is mainly inhabited by tribal population — Rabha, Bodo-Kachari, and Garo tribes. The study population were children under 1 year of age and their mothers. The study period was from October 2012 to March 2013.

Sample size and sampling technique

The sample size was calculated as 402 considering prevalence of LBW as 27.2%[4] and 20% relative error and design effect of 1.5 at 95% confidence interval (CI) (n = 4pq/L2). Taking 10% nonrespondents, the sample size was rounded up as 450. To get that sample, 30 villages were selected through cluster random sampling. From each cluster, 15 infants were selected randomly.

Inclusion criteria

All singleton infants, the infants whose parents gave written informed consent to be part of the study, and the infants whose parents who were permanent residents of the area.

Exclusion criteria

The infants whose birth weights were not known, the infants whose parents were not permanent residents of the area, the infants whose parents were not giving written informed consent.

Ethics

The study was approved by the Ethics Committee of the Gauhati Medical College and written, informed consent was obtained from all participants before any study related procedure was carried out.

Results

Demographics

A total of 450 infants were studied and 98/450 [21.8%] were found to be Low birth weight [LBW]. Of the 98, 45 were male and 53 were females. On analysis of socio-demographic variables, it was found that total 128 babies were born among the teenage mothers and among them numbers of LBW babies were more 46(36%). Among illiterate mothers 20 (22.2%) numbers of LBW babies were seen. Numbers of LBW babies found in joint families were 64 (20.6%) and 34 (24.3%) in nuclear families. Maximum LBW babies belonged to upper lower class (class IV) that is 43 (25.2%). In Muslim families 21 (26.2%) numbers of LBW babies were found. Chi-square test revealed statistically significant association between LBW and teenage pregnancy (P < 0.001), illiteracy (P < 0.02), and religion (P < 0.003) [Table 1].

Table 1

Distribution of study population according to socio-demographic variables

Variable	LBW (%)	NBW (%)	Chi-square test	P value
Age of mother (years)
≥19	46 (36)	82 (64)	22.44	P<0.0001
20-29	38 (14.8)	219 (85.2)
≥30	14 (21.6)	51 (78.4)
Mother's education status
Illiterate	20 (22.2)	70 (77.8)	9.246	P=0.026
Up to middle school	44 (29.5)	105 (70.5)
Up to HS	18 (15.9)	95 (84.1)
Graduate and above	16 (16.2)	82 (83.8)
Family type
Nuclear	34 (24.3)	106 (75.7)	0.75	P=0.386
Joint	64 (20.6)	246 (79.4)
Socioeconomic status (B.G Prasad classification)[12]
Upper class (class I) and Upper middle (class II)	10 (10.5)	57 (89.5)	3.40	P=0.33
Lower middle (class III)	34 (20.3)	133 (79.7)
Upper lower (class IV)	43 (25.2)	127 (74.8)
Lower class (class V)	11 (23.9)	35 (76.1)
Religion
Hindu	68 (24.9)	205 (75.1)	11.406	P=0.003
Muslim	21 (26.2)	59 (73.8)
Christian	9 (9.2)	88 (90.8)

Analysis of maternal factors [Table 2A and B] revealed that 26.9% of LBW babies are born of primipara mothers. There was also a high LBW percentage among the fourth or more para (30.4%). A very high LBW percentage of 44.5% was seen when interpregnancy interval was less than 18 months. LBW percentage was found to be higher among those women who had either no antenatal care (ANC) visits (42.8%) or less than 4 ANC visits (22.6%). Percentage of LBW was maximum (42.8%) in mothers who had not consumed any iron and folic acid tablets during pregnancy. The present study found maximum percentage of LBW babies (40%) among those women who had severe anemia. Among the mothers who had height of less than 145 cm, 28.6% had LBW babies. Those mothers who had previous history of abortions and stillbirth were also found to have high percentage of LBW babies (28%). Among the mothers who had gestational weight gain of less than 5 kg, 28.3% had LBW babies. LBW was significantly associated with the narrow interpregnancy interval (P < 0.02) and anemia during pregnancy (P < 0.001).

Table 2A

Distribution of study population according to maternal determinants

Variable	LBW (%)	NBW (%)	Chi-square test	P value
Parity of mothers
1	34 (26.9)	92 (73.1)	4.56	0.206
2	31 (19.7)	126 (80.3)
3	26 (18.05)	118 (81.95)
≥4	7 (30.4)	16 (69.6)
No. of ANC visits
Nil	3 (42.8)	4 (57.2)	0.279	0.597
<4	35 (22.6)	120 (77.4)
>4	60 (20.8)	228 (79.2)
IFA consumed in days
Nil	3 (42.8)	4 (57.2)	2.06	0.1512
<100	37 (25.2)	110 (74.8)
>100	58 (19.5)	238 (80.5)
Hemoglobin level (gm %) (N = 287)
<7	12 (40)	18 (60)	16.789	P=0.0002
7-9.9	27 (21.6)	98 (78.4)
10-10.9	10 (11.8)	85 (88.2)
>11	3 (8.1)	34 (91.9)
Interpregnancy interval (N = 324)
<18 months	8 (44.5)	10 (55.5)	7.484	P=0.0237
18-36 months	37 (18.9)	158 (81.1)
>36 months	19 (17.1)	92 (82.9)

Table 2B

Distribution of study population according to maternal determinants

Variable	LBW (%)	NBW (%)	Chi-square test	P value
Maternal height in cm
<145	8 (28.6)	20 (71.4)	2.2	P>0.05
145-154	17 (26.8)	46 (73.2)
155-165	73 (20.3)	286 (79.7)
Previous abortion and stillbirth
Present	12 (28.6)	30 (71.4)	0.853	P>0.05not significant
Absent	86 (21.1)	322 (78.9)
Gestational weight gain during pregnancy (N=375)
<5 kg	34 (28.3)	86 (71.7)	7.6	P>0.05not significant
5-8.9 kg	27 (18)	123 (82)
9-10.9 kg	12 (14.6)	70 (85.4)
>11 kg	3 (13.1)	20 (86.9)

On multiple logistic analysis of determinants of LBW babies, it was found that maternal anemia [odds ratio (OR) 1.93; CI 1.3-2.9], short interpregnancy interval (OR 3.93; CI 2.16-7.13), and teenage pregnancy (OR 3.93; CI 2.16-6.45) were the independent risk factors associated with LBW [Table 3].

Table 3

Logistic regression analysis of LBW and its determinants

Variable	Crude OR (95% CI)	Adjusted OR (95% CI)
Maternal anemia
Absent	1	1
Present	3.63 (2.2-6.0)	1.93 (1.3-2.9)
Age of the mother
19-30 years	1	1
Below 18 years	5.62 (2.35-13.42)	3.93 (2.16-6.45)
Above 30 years	1.14 (0.67-1.93)	1.21 (0.6-2.80)
Literacy status of mothers
High school and more	1	1
Illiterate	1.78 (1.04-3.07	1.59 (0.9-2.80)
Interpregnancy interval
More than 18 months	1	1
Less than 18 months	2.32 (1.2-5.67)	3.93 (2.16-7.13)
Religion
Hindu	1	1
Muslims	1.08 (0.508-2.28)	1.47 (0.91-2.35)

Discussion

The incidence of LBW in the present study was found to be 21.8%, which was slightly less than the national average of rural India (23%).[2] Still the high incidence of LBW in the study area could be a reflection of inadequate health care services in rural areas and poor maternal health conditions.

Present study found a significant association between the birth weight and teenage pregnancy. It may be due to the fact that teenage mothers are both physically and mentally less capable for bearing the burden of pregnancy. Banerjee et al. also found that the incidence of LBW was significantly higher among the teenage mothers.[5]

A significant association was found between mother's education status and birth weight of babies in the present study. Similarly, Kader et al. also reported that the percentage of LBW babies among illiterate mothers was high.[6] Our study found a statistically significant association between birth weight of babies and the religion. Similarly, Kaushal et al. also found higher percentage of LBW babies among Muslim mothers.[7]

Most of the mothers of LBW babies were found to be anemic during the antenatal period. Similarly, Mumbare et al. observed that maternal anemia is associated with delivery of a LBW infant.[8] Our study also found higher percentage of LBW babies among mothers who did not have adequate ANC checkups. Similar findings were also observed by Kader et al.[6]

The study found that short interpregnancy interval was significantly associated with LBW of the baby. Metgud et al. also had similar findings.[9]

The study found that among those mothers who had less weight gain during pregnancy, mothers with previous history of abortion, and mothers of short stature, the percentage of LBW was more. Study by Phaneendra Rao et al. also found that maternal height and weight gain during pregnancy were associated with birth weight.[10] Brown et al. also found that previous abortion is a significant risk factor for LBW.[11] Universal registration of pregnant women and good-quality ante natal care are both vital. Risk factors identified in the study can be used taken up and addressed by policy makers.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.