Birth mode and infectious morbidity risks in Qom children of Argentina.

OBJECTIVES: Cesarean delivery may increase childhood infectious morbidity risks via altered birth exposures and subsequent immune, microbial, and epigenetic development. Many Latin American indigenous populations experience dual burdens of infectious and chronic diseases, and are particularly vulnerable to rising rates of cesarean delivery and associated adverse outcomes. The Qom/Toba are an indigenous population in Argentina experiencing rapid lifestyle transitions. We hypothesized that cesarean delivery would be associated with increased risk of infectious symptoms in Qom children after adjusting for gestational and nutritional factors.

METHODS: We conducted a secondary analysis of birth records and monthly anthropometric and illness data collected previously from 90 Qom children (aged 1-55 months). We tested for additive effects of birth mode on risk of gastrointestinal (GI) and respiratory illness (RI) in mixed-effects logistic regression models adjusting for child weight-for-age (WAZ), weaning, and gestational and maternal age.

RESULTS: Cesarean deliveries accounted for 46% of births and were associated with maternal age < 20 and ≥ 30 years, gestational age < 39 weeks, and prenatal complications. GI and RI risks were reduced in association with cesarean delivery, greater WAZ, weaning, maternal age ≥ 30 years, and gestational age < 39 weeks.

CONCLUSIONS: The relationship between cesarean delivery and reduced infectious risks may reflect statistical confounding with relatively rapid postnatal growth and greater adiposity. Postnatal growth trajectories may be important mediators of long-term morbidity risks associated with cesarean delivery. The frequency of cesarean deliveries among the Qom remains concerning given traditionally high rates of fertility and adolescent pregnancy.