Incidence of small-for-gestational-age newborns in pregnant women with COVID-19

This study aimed to assess the incidence of small for gestational age (SGA) newborns in pregnant women infected with COVID-19 and examine the associated neonatal outcomes.

This study involved a secondary analysis of the REBRACO Network, a prospective cohort study conducted in 15 maternity hospitals in Brazil before the introduction of COVID-19 vaccination (February 2020 to February 2021). Demographic data of pregnant women tested for COVID-19 were analyzed, and fetal outcomes were compared between women with positive and negative COVID-19 results who had SGA fetuses.

A total of 729 symptomatic pregnant women with COVID-19 were included in the study. However, there were 248 participants with missing information regarding childbirth or loss of follow-up, and 107 participants without confirmatory tests for COVID-19. Among the remaining participants, 198 had confirmed COVID-19 and 176 tested negative. The incidence of SGA among women with COVID-19 was 22.4%, whereas the incidence among women who tested negative for COVID-19 was 14.8%. SGA newborns born to COVID-19 positive pregnant women were 1.6 times more likely to experience adverse outcomes (such as prematurity, stillbirth, neonatal death, and admission to a neonatal ICU) compared to non-SGA newborns [OR = 1.655 (1.145 - 2.394); P=0.017]. In SGA newborns of pregnant women with confirmed COVID-19 infection, mechanical ventilation use was found to be associated with the infection [OR = 0.692 (0.562 - 0.853); P=0.002].

The higher incidence of SGA newborns and its stronger association with prematurity in pregnant women with confirmed COVID-19 infection suggest that COVID-19 infection is a significant factor contributing to neonatal morbidity and mortality.