Pregnant hospitalized COVID-19 patients: disease, delivery, maternal and fetal outcomes

Pregnancy is a risk factor for severe COVID-19, however, the clinical course of pregnant patients hospitalized due COVID-19 is not well documented. We sought to prospectively assess outcomes of pregnant patients hospitalized for COVID-19, including pregnancy outcomes for mother and infant.

The Michigan Medicine COVID-19 Cohort (M²C²), is a prospective, observational study, which consecutively enrolled adult patients (aged ≥ 18 years) who were hospitalized for COVID-19 at Michigan Medicine from February 1, 2020, to October 30, 2022. All pregnant patients within the M²C² cohort were matched 4:1 by age and infection variant with non-pregnant female (M²C²) patients to examine the association of pregnancy with a composite outcome of in-hospital death and the use of mechanical or non-mechanical respiratory support. Manual chart review of the electronic medical record was conducted to ascertain pregnancy and infant outcomes.

Pregnant women hospitalized for COVID-19 (n = 54) were more likely to have higher body-mass index, asthma, and obstructive sleep apnea compared to matched-pregnant women who tested positive for COVID-19 but were non-hospitalized (n = 216). Eighteen (33%) pregnant patients hospitalized for COVID-19 (n = 54) exhibited the composite outcome, as well as 36 (17%) of matched non-pregnant women (n = 216). In-hospital mortality was similar between both groups; 2/54 (4%) pregnant vs. 6/216 (3%) non-pregnant women (P = 0.66). However, pregnant women had a higher likelihood of requiring respiratory support (OR 3.42, (95% CI [1.64, 7.13]) compared to non-pregnant women, driven by increased use of non-mechanical ventilation for 10/54 pregnant vs. 11/216 non-pregnant women (19% vs. 5%, respectively). Pregnant women in the third trimester (> 27 weeks) experienced the composite outcome (13/29) more often than those hospitalized for COVID-19 earlier in pregnancy (< = 27 weeks) (5/21) (45% vs. 24%). Of the eight pregnant women requiring mechanical ventilation (15%), one was vaccinated and seven were unvaccinated. Of those who delivered during their COVID-19 hospitalization (16/54), cesarean section was required for 75% of deliveries (12/16), 69% (11/16) were delivered preterm (< 37 weeks 0 days), and 44% (7/16) required admission to the neonatal intensive care unit immediately following birth.

Pregnant women hospitalized for COVID-19 may experience differences in clinical care and medical treatment received compared to non-pregnant women, including higher rates of non-invasive respiratory support. Pregnant women may be more likely to experience higher rates of preterm birth and infants may be more likely to need neonatal intensive care. Maternal outcomes from COVID-19 hospitalization may worsen as pregnancy progresses to later trimesters. Lower likelihood of experiencing poor outcomes may be attributed to vaccination.