Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in pregnancy is associated with preeclampsia, stillbirth, preterm birth and other adverse outcomes, found new research published in CMAJ (Canadian Medical Association Journal) .
"Our findings suggest that pregnant people with COVID-19 have an increased risk of high blood pressure, stillbirth and preterm birth. Their newborns are more likely to need intensive care. Pregnant people with severe COVID-19 symptoms have a particularly high risk of these complications," says Dr. Nathalie Auger, Department of Social and Preventive Medicine, School of Public Health, University of Montreal, Montréal, Quebec, with coauthors.
Researchers reviewed 42 studies involving 438 548 pregnant people from around the world to determine the association between SARS-CoV-2 infection and adverse pregnancy outcomes. They found double the risk of preterm birth and a 50% increased risk of cesarean delivery in pregnant people with symptomatic COVID-19 than in those with asymptomatic COVID-19. Those with severe COVID-19 had a 4-fold higher risk of high blood pressure and preterm birth.
The reason for the increased risk of adverse outcomes is unclear, but could be because SARS-CoV-2 may lead to vasoconstriction and stimulate an inflammatory response affecting blood vessels.
The findings of this systematic review differ from prior findings from case reports and case series. "Our meta-analysis of recent good-quality cohort studies with comparative data does not align with these previous reviews, and provides clear evidence that symptomatic or severe COVID-19 is associated with a considerable risk of preeclampsia, preterm birth and low birth weight," write the authors.
"Clinicians should be aware of these adverse outcomes when managing pregnancies affected by COVID-19 and adopt effective strategies to prevent or reduce risks to patients and fetuses," they conclude.
"The impact of COVID-19 on pregnancy outcomes: a systematic review and meta-analysis" is published March 19, 2021.
Canadian Medical Association Journal