COVID-19 infection in early pregnancy ups risk of stillbirth

Pregnant women who contract COVID-19 during early and mid-pregnancy are at risk of stillbirth, but this risk may not be present when infection occurs at any time during the third trimester or before delivery, as reported in a study.

For this retrospective cohort study, data from 75 healthcare systems and institutes across 50 states in the US were used. The analysis included 191,403 pregnancies among 190,738 women of reproductive age (15–49 years) who had childbirth.

The main study endpoint was stillbirth, which was defined as an event that occurred at or after 20 weeks of gestation. The timing of SARS-CoV-2 infection was categorized as follows: early pregnancy (<20 weeks), mid-pregnancy (21–27 weeks), third trimester (28–43 weeks), and any time before delivery.

COVID-19 infection occurred in 2,342 women (1.3 percent) during early pregnancy, in 2,075 (1.2 percent) during mid-pregnancy, and in 12,697 (6.9 percent) during the third trimester.

In multivariable logistic regression analysis adjusted for the maternal and clinical characteristics, the odds of stillbirth were significantly higher among pregnant women with SARS-CoV-2 infection that occurred in early pregnancy (odds ratio [OR], 1.75, 95 percent confidence interval [CI], 1.25–2.46) or mid-pregnancy (OR, 2.09, 95 percent CI, 1.49–2.93) as compared with those who were never infected.

Other factors that predicted stillbirth across different trimesters were older age, Black race, hypertension, acute respiratory distress syndrome or acute respiratory failure, and placental abruption.

The findings suggest the potential vulnerability of the foetus to the SARS-CoV-2 infection in early pregnancies. As such, proactive COVID-19 prevention or timely medical intervention is important for women infected with SARS-CoV-2 during early and mid-pregnancy.