Background: Limited data are available on the impact of COVID-19 on pregnant women and their newborns.
Objectives: To quantify the impact of having a COVID-19 diagnosis during pregnancy on fetal outcomes for first-time pregnant women.
Methods: Women aged 12-55 with evidence of pregnancy from 4/1/2020-6/30/2023 were identified in a US dataset that includes administrative claims for over 3 million mother-infant pairs across commercial payers, Medicare Advantage, and Medicaid. Only a mother’s first pregnancy episode was selected among episodes resulting in a live birth. A cohort of mothers with COVID-19 occurring between the estimated pregnancy start date and date of delivery (date of COVID-19 ICD-10 diagnosis deemed index date) were propensity score matched 1:1 to mothers without COVID-19 during pregnancy (random index date within pregnancy time period assigned) based on age at index, region, race, index year, trimester of index, Charlson Comorbidity Index, and presence of obesity. Outcomes of interest were proportion of pregnancy episodes with pre-term birth or low birth weight, controlling for the number of COVID-19 vaccines prior to index.
Results: 63,733 mother-infant pairs with evidence of COVID-19 during pregnancy were matched 1:1 to non-COVID-19 controls (overall sample median age, 29 [IQR: 25-33]; 40.63% reside in Southern US region; 35.93% Caucasian). A significantly greater proportion of mothers with COVID-19 experienced pre-term birth (4.81%) compared to mothers without COVID-19 (4.32%; p < 0.0001), with this difference persisting after adjusting for number of COVID vaccinations prior to index (odds ratio [OR]: 1.12, 95% CI: 1.06-1.18). In contrast, a slightly greater proportion of mothers without COVID-19 had infants with low birth weight (10.58% vs. 10.15%, p=0.012; adjustment for vaccinations, OR: 0.95, 95% CI: 0.92-0.99).
Conclusions: Pregnant mothers with COVID-19 may experience increased odds of pre-term birth but not low birth weight. Future research is needed to further understand the association between COVID-19 and fetal outcomes in first-time mothers.
