(28) Impact of Maternal SARS-CoV-2 Infection and Immunization Status on Intrauterine Growth

Henna Park, University of Illinois at Chicago, Chicago, IL, United States; Zaynab Kadhem, University of Illinois at Chicago, United States; De-Ann Pillers, University of Illinois at Chicago, United States; Joann Romano-Keeler, University of Illinois at Chicago, United States

Background: Histopathologic changes of the placenta have been observed after maternal SARS-CoV-2 infection during pregnancy. Such changes may result in placental insufficiency and adversely impact fetal development, including growth. In intrauterine growth restriction (IUGR), a fetus fails to achieve its growth potential. It is estimated to affect 10-15% of pregnancies worldwide and pose a greater long-term risk of cardiovascular and metabolic disorders for these infants. To date, no studies compare the incidence of IUGR between immunized and unimmunized SARS-CoV-2 positive (SARS-CoV-2+) mothers. In this study, we report the analysis of 126 infants born to SARS-CoV-2+ mothers at the University of Illinois at Chicago of varying immunization status.

Objectives: Our objectives were to: 1) Determine the incidence of IUGR infants among immunized and unimmunized SARS-CoV-2+ mothers. 2) Evaluate other markers of placental insufficiency, including preeclampsia, gestational hypertension, and prematurity.

Design/Methods: We conducted a retrospective chart review of infants born between March 2020 and May 2022 to laboratory confirmed SARS-CoV-2+ mothers. IUGR was defined as fetal weight < 10th percentile for gestational age. Baseline information collected included maternal age, perinatal complications, gestational age, and growth parameters at birth. Data was stratified by maternal SARS-CoV-2 immunization status.

Results: A total of 126 mother-infant dyads were analyzed. Mean maternal age was 27 (17-43) years. Mothers were predominantly African American (n = 78) or Latinx (n = 38). 33% (n = 42) were immunized and 67% (n = 84) were unimmunized. Mean gestational age was 37 (29-41) weeks and mean birth weight was 2014 (1360-4335) grams. Growth restriction was observed in 25 infants (20%), of which 14 (56%) had restricted birthweights, but normal head circumferences and lengths. Perinatal complications included preeclampsia (n = 26, 21%), gestational hypertension (n = 11, 9%), and prematurity (n = 21, 17%). 22 of 26 (85%), 9 of 11 (82%), and 12 of 21 (57%) of mothers were unimmunized, respectively.

Conclusion: Compared to historic levels, the incidence of IUGR was greater among SARS-CoV-2+ mothers. IUGR and other perinatal complications, suggestive of placental insufficiency, were largely observed in infants born to unimmunized mothers. Further studies are warranted to determine the impact of SARS-CoV-2 on placental function and fetal growth and the role of immunization on preventing placental insufficiency secondary to SARS-CoV-2.