Maternal obesity, neonatal morbidity, and mortality, Southeast Metropolitan Health Service, Chile, 2014-2018. A retrospective cohort.

Introduction: Obesity represents a worldwide concern with growing prevalence over the years.Maternal obesity is an established risk factor for mothers and newborns. We aim to study the relationship between maternal obesity, neonatal morbidity, and mortality.Population and Methods: We conducted a retrospective cohort study from the Southeast Metropolitan Health Service birth database from (2014-2018), (n=19,946 mothers and newborns). We collected sociodemographic variables, nutritional status at the beginning and during pregnancy, and morbid antecedents for mothers.Data of newborns corresponded to birth, perinatal, and neonatal health conditions. We estimated means and frequencies. Relative risk, Odds ratio, p-value <0.05 and 95% CI determined statistical association. Multivariate analysis with logistic regression controlled confounding factors.Results and Discussion: Most incident neonatal morbidities and health conditions were fetal macrosomia (9.2%), and hospitalization (10.6%). Neonatal mortality (NM) was (5.2 ‰). Regarding mothers, 28.8% was obese, with difference from non-obese as age, educational level, socio-economic level, and morbid antecedents as diabetes mellitus. Risk of NM (ORa =1.5; 95% CI = 1.1-2.3) and fetal macrosomia (ORa =1.7; 95% CI = 1.7-2.1) was higher in newborns of obese mothers compared to those of non-obese mothers. Excessive gestational weight gain rate presented positive association with fetal macrosomia and neonatal emergency admission (ORa = 1.2; 95% CI =1.1-1, 4), but did not associate with NM (p = 0.265). Maternal obesity is confirmed as a risk for newborns, which is biologically plausible. It is recommended to promote the maintenance of normal weight before pregnancy and adequate gestational weight gain.