COVID-19 research briefs: Pregnant women may manifest fewer symptoms, but may need more intensive treatment if symptomatic

Reference

Allotey J, Stallings E, Bonet M, et al, for the PregCOV-19 Living Systematic Review Consortium. Clinical manifestations, risk factors, and maternal and perinatal outcomes of coronavirus disease 2019 in pregnancy: living systematic review and meta-analysis. BMJ. 2020;370:m3320.

Synopsis

Research Brief #59: These authors used modern meta-analytic methods, including searching multiple databases to find studies that reported data on pregnant women with suspected or confirmed COVID-19. This is a "living systematic review" with frequent updates, including monthly reporting through a dedicated website (COVID-19: a living systematic map of the evidence). For this publication, they included 77 studies with 13,118 pregnant and recently pregnant women with covid-19 and 83,486 non-pregnant women of reproductive age with covid-19. Roughly 1/3 of the studies came from the US and 1/3 from China. All of the studies used PCR to confirm the presence of COVID-19. Overall, for study trustworthiness (internal validity), 75 (96%) of the studies were at low risk of bias. However, only 10 of the studies were thought to be low risk of bias when it comes to representativeness (external validity). Overall, the rate of COVID-19 in pregnant and recently pregnant women was 10% (95% CI 7% to 14%), although the rate varied by the testing strategy. For example, in the studies that used universal testing, 7% of the pregnant women (range 4% to 10%) had COVID compared with 18% (range 10% to 28%) in the studies that tested based on symptoms. In the 26 studies that reported mortality data, 73/11,580 (0.1% but with high heterogeneity) of pregnant women with COVID-19 died. They fail to report the same rates for non-pregnant women or for uninfected pregnant women. Overall, pregnant women were less likely to have fever (OR 0.43, 95% CI 0.22-0.85, but high heterogeneity) and myalgias (OR 0.48, 95% CI 0.45-0.51, no heterogeneity). Compared with non-pregnant women of reproductive age with COVID-19, pregnant women with COVID-19 were more likely to require intensive care (OR 1.62, 95% CI 1.33-1.96; no heterogeneity) or mechanical ventilation (OR 1.88, 95% CI 1.36-2.60; no heterogeneity). Among the women who died, higher mortality was associated with increased maternal age, high body mass index, chronic hypertension and pre-existing diabetes. The presence of comorbidity was also associated with a higher risk of intensive care admission and mechanical ventilation. Overall, 17% (95% CI 13-21) of pregnant women with COVID-19 had preterm births and 6% (95% CI 3-9) had a spontaneous preterm delivery. Additionally, 18 of 2837 (0.6%) pregnancies among women with COVID resulted in a stillbirth and 6 of 1728 neonates (0.3%) died. Overall, these data suggest that pregnant women with COVID-19 are less likely to have typical symptoms and are more likely to require intensive care or mechanical ventilation. While this paper is data intense, the limited reporting of comparison data prevents making too many conclusions.