Effect of diarrheal illness during pregnancy on adverse birth outcomes in Nepal

Background. Adverse birth outcomes, including low birthweight, small for gestational age (SGA), and preterm birth, contribute to 60%-80% of infant mortality worldwide. Little published data exist on the association between diarrhea during pregnancy and adverse birth outcomes. Methods. Data were used from 2 community-based, prospective randomized trials of maternal influenza immunization during pregnancy conducted in rural Nepal from 2011 to 2014. Diarrheal illnesses were identified through longitudinal household-based weekly symptom surveillance. Diarrhea episodes were defined as at least 3 watery bowel movements per day for 1 or more days with 7 diarrhea-free days between episodes. The Poisson and log-binomial regression were performed to evaluate baseline characteristics and association between diarrhea during pregnancy and adverse birth outcomes. Results. A total of 527 of 3693 women in the study (14.3%) experienced diarrhea during pregnancy. Women with diarrhea had a median of 1 episode of diarrhea (interquartile range [IQR], 1-2 episodes) and 2 cumulative days of diarrhea (IQR, 1-3 days). Of women with diarrhea, 85 (16.1%) sought medical care. In crude and adjusted analyses, women with diarrhea during pregnancy were more likely to have SGA infants (42.6% vs 36.8%; adjusted risk ratio = 1.20; 95% confidence interval, 1.06-1.36; P = .005). Birthweight and preterm birth incidence did not substantially differ between women with diarrhea during pregnancy and those without. Conclusions. Diarrheal illness during pregnancy was associated with a higher risk of SGA infants in this rural South Asian population. Interventions to reduce the burden of diarrheal illness during pregnancy may have an impact on SGA births in resource-limited settings.