COVID-19 Pandemic Impact on the Birth Weight of Children Born in a Brazilian Metropolis.

Objective: To assess the birth weight of newborns whose mothers gave birth during the COVID-19 pandemic.

Methods: A cross-sectional study based on data collected from medical records and through postnatal interviews to assess maternal and neonatal health outcomes (n = 470) during the pandemic. All participants were assisted in three Brazilian public hospitals in 2020. Multinomial logistic regression was performed to assess factors associated with birth weight.

Results: Low and insufficient birth weight reached 9.8% and 25.7% prevalence, respectively. COVID-19 symptoms were reported by 8% of participants. Low birth weight was more often observed in premature children (OR: 70.9; 95% CI: 16.4-305.8) delivered by cesarean sections (OR: 7.70; 95% CI: 2.33-25.4). Insufficient weight was more frequent in premature children (OR: 5.59; 95% CI: 1.53-20.4) and children whose mothers did not exercise during pregnancy (OR: 2.85; 95% CI: 1.38-5.89). Women presenting higher gestational weight gain had a lower chance of delivering babies with insufficient weight (OR: 0.94; 95% CI: 0.90-0.99).

Conclusions: Inadequate birth weight was associated with prematurity, delivery type, lower gestational weight gain, and maternal physical inactivity during the pandemic. According to the results, it is necessary to have adequate prenatal care and promote a healthy lifestyle during pregnancy.