Are Female Children More Likely to be Born to Indian Anesthesiologists? - A Nationwide Survey.

CONTEXT: Exposure to medications (prescribed or over-the-counter) or exposure to chemicals (unintentional or occupational) during pregnancy have always been of great scientific concerns. AIMS: This study aims to ascertain whether the recently documented offspring sex ratio (OSR) skew in medical literature is reproducible among our respondent population and how our respondents' characteristics relate to the OSR skew (if any) in our respondent population. SETTINGS AND
DESIGN: A survey questionnaire uploaded on the SurveyMonkey® Online Portal. SUBJECTS AND METHODS: The survey was completed by the Indian anesthesiologists about themselves and their spouses during the periconceptional periods of their offspring. STATISTICAL ANALYSIS USED: Analysis of variance for means and Chi-square test for proportions with P < 0.05 as statistically significant.
RESULTS: Respondents (irrespective of gender) who sired first-born or second-born male children were anyway more likely to sire male children as reflected in the personal sex ratios among all offspring sired by them, and similarly respondents (irrespective of gender) who sired first-born or second-born female children were anyway more likely to sire female children. Male parents were significantly more common to have worked in operating rooms around the time of conception of first-born or second-born children. As compared to female anesthesiologists, male anesthesiologists significantly reported that they were practicing inhalational induction of anesthesia more often around the conception of their second-born female children as compared to around the conception of their second-born male children.
CONCLUSIONS: Practice of inhalational induction of anesthesia was reportedly more common among Indian male anesthesiologists during periconceptional period of their second-born female children.

INTRODUCTION

The American researchers as well as Indian researchers independently elicited skew in offspring sex ratio (OSR) born to anesthesiologists favoring more frequent siring of female children by them.[12345] However, survey-based study results can be marred by bias, and therefore, there are never too many survey-based studies to ascertain validity and reproducibility of the prior study results. The primary objective of the current survey was to ascertain whether the recently documented OSR skew in medical literature is reproducible among our respondent population and how our respondents' characteristics relate to the OSR skew (if any) in our respondent population.

SUBJECTS AND METHODS

After Institutional Review Board approval for survey-based research protocol, a survey questionnaire was uploaded on the SurveyMonkey® Online Portal [Appendix 1]. Subsequently, the created web-link for completing the questionnaire was sent out to the Indian anesthesiologists through their E-mail addresses as available in the member directory of the Indian Association of Anaesthesiologists. The answers collected from the respondents to these questionnaires were about themselves and their spouses during the periconceptional periods (8–10 months before birth) of their offspring. The data were about the following: respondents' gender, experience (in years) of anesthesia practice, current status as resident anesthetist/nonpediatric/nonselective/pediatric anesthetist, and number of children sired (if any) with the genders of the offspring. Subsequent parental data were about around the times of conception of offspring: age, whether worked in operating rooms, whether worked in academic/private practice, working hours in operating rooms, anesthesia systems (closed/open circuits) used in those operating rooms, propensity for practicing inhalational induction of anesthesia, availability of scavenging systems in the operating rooms, and working hours in nonscavenging operating rooms.

Statistical analysis

The data were subsequently tabulated and analyzed by analysis of variance for means and Chi-square test for proportions. The aim was to recognize statistically significant data (if any) at P < 0.05 when comparing the male anesthesiologists who sired male children versus who sired female children, with the female anesthesiologists who sired male children versus who sired female children.

RESULTS

Of 9986 unique E-mail invitations sent out for completion of our survey questionnaire, only 5040 people (50%) opened their E-mail invitations; however, only 1553 people responded (response rate was 16%) and among the respondents, due to very high incompletion rates and consequent missing homogeneous data, only 499 respondents' data were amenable to statistical analysis in regards to their first-born children (if any), and only 274 respondents' data were amenable to statistical analysis in regards to their second-born children (if any). The comprehensive completion of the analyzable survey data was provided by 32% of respondents. The data and their statistical significance have been tabulated in Tables 1a–d for first-born children and [Tables 2a–d] for second-born children. As compared to expected sex ratio of 1000 males per 940 females based on Census of India (2011),[6] the children sired by Indian anesthesiologists did NOT show any significant differences in their sex ratios. The only statistically significant (key) findings of survey results were following: (a) respondents (irrespective of their gender) who sired first-born or second born male children were anyway more likely to sire male children as reflected in the personal sex ratios among all offspring sired by them, and similarly respondents (irrespective of their gender) who sired first-born or second born female children were anyway more likely to sire female children; (b) male parents were significantly older than female parents around the time of conception of first-born or second-born children; (c) male parents were significantly more common to have worked in operating rooms around the time of conception of first-born or second-born children; and (d) as compared to female anesthesiologists, male anesthesiologists significantly reported that they were practicing inhalational induction of anesthesia more often around the conception of their second-born female children as compared to around the conception of their second-born male children.

Table 1a

First-born children to Indian anesthesiologists characteristics part-I

Table 1d

First-born children to Indian anesthesiologists characteristics part-IV

Table 2a

Second-born children to Indian anesthesiologists characteristics part-I

Table 2d

Second-born children to Indian Anesthesiologists characteristics part-IV

DISCUSSION

Exposure to medications (prescribed or over-the-counter) or exposure to chemicals (unintentional or occupational) during pregnancy have always been of great scientific concerns because testing for validity about effects (if any) of exposures during pregnancy has inbuilt experimental debacle. The reason for this scientific debacle lies in the fact that most of the data related to effects of exposure during pregnancy is interpreted from animal experiments or human self-report studies because the randomized controlled studies among the healthy human volunteers may not be ethical or possible considering the yet-to-define unknown levels of maternal-fetal risks involved with any potential chemical exposure; however, it cannot be denied that an adequate sample size prospective study investigating these potential effects is less prone to statistical biases but takes longer time to be completed. Furthering this garb of exposure to beyond the limits of known pregnancies, the conception periods of future generations may itself fall at risk under the cloak of potential chemical exposures wherein humans irrespective of their gender may need to be cautious during their entire reproductive age that has potential to fall in unintentional conception periods for unplanned pregnancies unless they strictly follow planned conception periods for wanted pregnancies. Herein lies the avenue for investigations into occupational hazards specific to reproductive age operating room personnel and anesthesiologists in particular. As compared to intravenous anesthetic agents that are administered through perfectly closed intravenous delivery systems and primarily excreted through liver and kidneys, inhalational anesthetic agents are primarily exhaled out and exchanged through imperfectly closed anesthetic gas delivery systems. This leads to much more likelihood to unintentional occupational exposure of anesthesiologists to inhaled anesthetic agents in gaseous forms.

Interestingly, the chemical exposure related maternal-fetal risks can primarily be assessed by self-reports/surveys because of ethical limitations in regard to conducting randomized controlled trials in healthy pregnant human volunteers and longer duration required for completing adequate sample-sized and statistical error-resistant prospective studies. However, survey-based study results can be marred by nonresponse bias, voluntary response bias (self-selection bias) and selection bias, and therefore, there are never too many survey-based studies to ascertain validity and reproducibility of the prior study results. Moreover, self-report surveys are marred by low response rates and low completion rates especially if they are voluntary and not mandatory.

Compared to other recent studies with analyzed survey respondents' numbers being 314 and 888 that demonstrated statistical significance favoring female offspring,[2345] and in spite of our survey trends appearing different (national sex ratio: 940 females per 1000 males; our survey's first-born sex ratio: 957 females per 1000 males; our survey's second-born sex ratio: 1045 females per 1000 males; our survey's combined first-second-born sex ratio: 987 females per 1000 males), our results did not achieve statistical significance most likely because of either extremely low numbers of respondents who completed the survey, or absence of overt skew favoring female offspring born among our respondent population.

It is not clear whether voluntary response bias (self-selection bias) secondary to our survey respondents' unknown strong personal opinions about anesthesia work environments' effects on OSR at the time when they had received our survey-invite titled “Anaesthesia Practice – Does it have an impact on Sex – Ratio amongst their offsprings? – a nationwide survey” [Appendix 1] and/or nonresponse bias marring self-report surveys with low response rates could explain our results; however, there were certain interesting findings among our results. Around the time of conceiving offspring, Indian male anesthesiologists on an average were in their thirties and 2–4 years older to their spouses, reflecting potential parental age trends prevalent among physicians and potential parental age differences among Indians. Respondents were innately more likely to sire either male offspring or female offspring that may have acted as physiological confounding factor affecting the statistical significance or clinical interpretation of our results; however, this inherent physiological propensity to sire gender-specific offspring might be affecting other self-report surveys and hence its confounding effect needs to be quantified for better interpretation of the studies eliciting OSRs and factors affecting OSRs.[23]

More than half of our respondent population was working in academic institute setting as compared to private practice setting that may reflect the potential likelihood among academic physicians to explore the unknown prompting them to contribute to our self-report survey. More than 80% of respondents (especially male anesthesiologists) were working in the operating rooms around the time of conceiving offspring reflecting the absence of convincing data elicited by well-designed studies to alert them otherwise unless anesthesiologists have safely assumed by default that there is nothing to worry about in regard to chronic unintentional occupational exposure to inhaled chemical agents. This is especially worrisome when less than one-fourth of our respondent population was exclusively using closed anesthesia gas delivery systems which are themselves imperfect in regard to prevention of occupational exposure without the scavenging systems in the operating rooms where almost three-fourths of our respondent population were working.

Finally, around the time of conceiving their second-born female children, male anesthesiologists reportedly were practicing inhalational induction of anesthetic agents more often, thus exposing themselves to increased amounts of leaking anesthetic gas agents around the anesthesia masks.[7] This was the only statistically significant finding of our study (P = 0.01) that itself could have been confounded by our Indian male respondent population who could have overestimated their level of exposure (related to inhalational induction anesthesia practice) presuming correlation (with potential subconscious blaming) of inhalational anesthetics with female gender of their second-born wherein the second child often represents completion of modern nuclear Indian families despite, (similar to other East Asians) Indian psyches (overtly or covertly) being still deep-rooted in having at least one male child to complete the family.[8910] Moreover, the selection bias in our study cannot be quantified because the anonymity of survey invitees' characteristics as well as the corresponding anonymity of survey respondents' characteristics precluded whether the survey respondents' sample was a representative sample of the practicing anesthesiologists (survey invitees) across the various geographical regions of India. However, the propensity of male anesthesiologists to sire second-born female children became statistically stronger (20% as compared to 6% for second-born male children; P = 0.003) when they had reported often-to-always practicing inhalational induction of anesthesia with equal to or >6 h daily work-exposure in their nonscavenging operating rooms; and this statistical finding may somewhat indicate the validity of our study results despite our survey's low response rate.

Limitation of study

Our study raised more questions instead of answering them. One thing was certain that self-report surveys can only be stepping stones because randomized controlled trials and basic laboratory research are the primary methods to eventually prove or refute the science that could convincingly explain the occurrence of phenomena. However, the medical researchers' hands are tied because of catch-22 situation in regards to ethical concerns regarding pregnant human volunteers' research and the research based on human semen samples (potentially perceived as invasion of privacy) that may explain OSR changes (innate/physiological or otherwise/pathological) by potentially quantifying changes in X-bearing sperms and Y-bearing sperms not only inside the paternal genital tracts but also inside the maternal genital tracts.[11] Therefore, they would have to continue to rely on the results of self-reports surveys like ours to recommend or alert population against unnecessary chemical agents' exposure not only during the pregnant periods but also during the periconceptional periods that may potentially extend over the entire reproductive age for the unplanned pregnancies. Although low response rate with potential nonresponse bias and selection bias may question the validity of our results, our survey findings may still inspire future investigators to test the questions raised by our study results.

CONCLUSIONS

In summary, among our limited respondent population, practice of inhalational induction of anesthesia was reportedly more common among Indian male anesthesiologists during the periconceptional period of their second-born female children; however, larger surveys and/or laboratory studies need to be designed to answer whether this is just an association reflecting coexistence of two factors or a direct causation with one factor leading to the other.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Table 1b

First-born children to Indian anesthesiologists characteristics part-II

Table 1c

First-born children to Indian anesthesiologists characteristics part-III

Table 2b

Second-born children to Indian Anesthesiologists characteristics part-II

Table 2c

Second-born children to Indian anesthesiologists characteristics part-III