ABSTRACT
OBJECTIVES: We describe clinical characteristics, pregnancy, and infant outcomes in pregnant people with laboratory-confirmed SARS-CoV-2 infection by trimester of infection. STUDY DESIGN: We analyzed data from the Surveillance for Emerging Threats to Mothers and Babies Network and included people with infection in 2020, with known timing of infection and pregnancy outcome. Outcomes are described by trimester of infection. Pregnancy outcomes included live birth and pregnancy loss (<20 weeks and ≥20 weeks gestation). Infant outcomes included preterm birth (<37 weeks gestation), small for gestational age, birth defects, and neonatal intensive care unit admission. Adjusted prevalence ratios (aPR) were calculated for pregnancy and selected infant outcomes by trimester of infection, controlling for demographics. RESULTS: Of 35,200 people included in this analysis, 50.8% of pregnant people had infection in the third trimester, 30.8% in the second, and 18.3% in the first. Third trimester infection was associated with a higher frequency of preterm birth compared to first or second trimester infection combined (17.8% vs. 11.8%; aPR 1.44 95% CI: 1.35-1.54). Prevalence of birth defects was 553.4/10,000 live births, with no difference by trimester of infection. CONCLUSIONS: There were no signals for increased birth defects among infants in this population relative to national baseline estimates, regardless of timing of infection. However, the prevalence of preterm birth in people with SARS-CoV-2 infection in pregnancy in our analysis was higher relative to national baseline data (10.0-10.2%), particularly among people with third trimester infection. Consequences of COVID-19 during pregnancy support recommended COVID-19 prevention strategies, including vaccination.
ABSTRACT
OBJECTIVE: We examined the relationship between trimester of SARS-CoV-2 infection, illness severity, and risk for preterm birth. STUDY DESIGN: We analyzed data for 6336 pregnant persons with SARS-CoV-2 infection in 2020 in the United States. Risk ratios for preterm birth were calculated for illness severity, trimester of infection, and illness severity stratified by trimester of infection adjusted for age, selected underlying medical conditions, and pregnancy complications. RESULT: Pregnant persons with critical COVID-19 or asymptomatic infection, compared to mild COVID-19, in the second or third trimester were at increased risk of preterm birth. Pregnant persons with moderate-to-severe COVID-19 did not show increased risk of preterm birth in any trimester. CONCLUSION: Critical COVID-19 in the second or third trimester was associated with increased risk of preterm birth. This finding can be used to guide prevention strategies, including vaccination, and inform clinical practices for pregnant persons.