The Dual Burden of Malnutrition Increases the Risk of Cesarean Delivery: Evidence From India

Abstract

Background: Among contemporary human populations, rates of cesarean delivery vary substantially, making it difficult to know if the procedure is inadequately available, or used excessively relative to medical need. A much-cited evolutionary hypothesis attributed birth complications to an "obstetric dilemma," resulting from antagonistic selective pressures acting on maternal pelvic dimensions and fetal brain growth during hominin evolution. However, the childbirth challenges experienced by living humans may not be representative of those in the past, and may vary in association with trends in ecological conditions. We hypothesized that variability in maternal phenotype (height and nutritional status) may contribute to the risk of cesarean delivery. In many populations, high levels of child stunting contribute to a high frequency of short adult stature, while obesity is also becoming more common. The combination of short maternal stature and maternal overweight or obesity may substantially increase the risk of cesarean delivery. Methods: Using data from two large Indian health surveys from 2005-6 to 2015-2016, we tested associations of maternal somatic phenotype (short stature, overweight) with the risk of cesarean delivery, adjusting for confounding factors such as maternal age, birth order, rural/urban location, wealth and offspring sex. Results: Secular trends in maternal body mass index between surveys were greater than trends in height. Maternal short stature and overweight both increased the risk of cesarean delivery, most strongly when jointly present within individual women. These associations were independent of birth order, wealth, maternal age and rural/urban location. Secular trends in maternal phenotype explained 18% of the increase in cesarean rate over 10 years. Conclusion: Our results highlight how the emerging dual burden of malnutrition (persisting short adult stature which reflects persistent child stunting; increasing overweight in adults) is likely to impact childbirth in low and middle-income countries.

Keywords: India; South Asia; cesarean; dual burden of malnutrition; obesity; obstetric dilemma; overweight; short stature.

Figure 1

Median values for (A) height and (B) body mass index by 5-year age group in the 2005–2006 survey, with the increment demonstrated by the 2015–2016 survey. Increments are adjusted for wealth and rural-urban location so as to match the profile of the baseline survey.

Figure 2

Rates of C-section stratified by (A) 5-year age group, (B) birth order, (C) wealth category group (5 = wealthiest) and (D) infant birth size in the 2005–2006 survey, with the increment in the rate demonstrated by the 2015–2016 survey.

Figure 3

Interactive associations of birth order and wealth category with the rate of C-section in the 2015–1016 survey (5 = wealthiest). Numbers per group are given in Table S3.

Figure 4

Odds of cesarean delivery associated with short stature, overweight and obesity, or their combination within mothers, in the whole sample. Results from logistical regression models, adjusted for maternal age, birth order, rural/urban status, offspring sex, offspring birth size, births within survey and wealth index. Error bars represent 95% confidence intervals.

Figure 5

Interactive associations of wealth category and maternal somatic phenotype with the crude rate of C-section. Numbers per group are given in Table S3.

Figure 6

Odds of cesarean delivery associated with short stature, overweight and obesity, or their combination within mothers, stratified by wealth category (5 = wealthiest). Results from logistical regression models, adjusted for maternal age, birth order, rural/urban status and offspring sex. Numbers per group are given in Table S3.