(1145) Postnatal growth trajectories of offspring exposed to maternal SARS-CoV-2 infection: a pandemic era cohort study

Prior birth cohorts have suggested an association between maternal infection in pregnancy and offspring risk for childhood obesity.  The objective of this study is to determine whether in utero exposure to SARS-CoV-2 is associated with differences in offspring weight, length, BMI, systolic and diastolic blood pressure at 12 months of age.

Study Design: This electronic health records-based cohort study included the live offspring of all individuals who delivered during the COVID-19 pandemic (March 1, 2020 - May 31, 2021) at any of 8 hospitals within the Mass General Brigham network.  Exposure was defined as a positive SARS-CoV-2 PCR during pregnancy. Offspring weight, length, and BMI percentiles for age were determined using sex-specific WHO growth curves at birth and 12 months (+/- 30 days).  Differences in mean offspring weight-for-age, length-for-age, and BMI-for-age percentiles and mean systolic and diastolic blood pressure (BP) between groups were compared at birth and 12 months (Welch’s two sample t-test).

Results: The study cohort included 18,323 pregnancies (17,446 unexposed and 877 exposed offspring). Maternal age, gestational age, public insurance, and diabetes were significantly different in SARS-CoV-2 positive pregnancies (Fig. 1A). At birth, weight-for-age percentiles were lower in exposed infants (p< 0.001, Fig. 1B); no difference was observed in mean length-for-age or BMI-for-age percentiles. At 12 months of age, mean BMI-for-age percentiles and weight-for-age percentiles were significantly higher in exposed vs. unexposed offspring (p=0.005 and p=0.03, respectively, Fig. 1B).  No significant differences in mean systolic or diastolic BP were observed between groups at 12 months.

Conclusion: Altered growth patterns with lower weight-for-age percentiles at birth and higher weight- and BMI-for age percentiles at 12 months of age were observed in infants with in utero exposure to maternal SARS-CoV-2 infection.  Larger cohorts and longer follow-up will be necessary to assess the clinical significance of these findings and evaluate risk across the lifespan.