Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the first trimester of pregnancy does not appear to predispose to early pregnancy loss, according to data published in The American Journal of Obstetrics and Gynecology. Coronavirus disease 2019 (COVID-19) appears to have a favorable maternal course at the beginning of pregnancy, consistent with observations made during the second and third trimesters.
Between February 22 and May 21, investigators compared the cumulative incidence of COVID-19 in a case group of 100 women with spontaneous abortion and a control group of 125 women with ongoing pregnancy in Turin, Italy. All participants were in the first trimester and paired for last menstruation. Of the 23 women (10.2%) who tested positive for COVID-19, 11 women (11%) were in the spontaneous abortion group and 12 women (9.6%) were in the control group.
The mean (±SD) age for women in the case group was 35.5 (±4.7) and 33.7 (±4.7) in the control group (P =.001); all other baseline characteristics were similar in both groups. COVID-19 was not an independent predictor of early pregnancy loss (odds ratio [OR], 1.28; 95% CI, 0.53-3.08). A subgroup analysis of baseline characteristics between COVID-19-positive and -negative patients found no statistical differences in demographics or risk factors except for BMI (26.4 [±5.2] vs 23.2 [±4.2]; P =.03).
Investigators noted that while the number of infected patients in the case group was low, their similarity in terms of characteristics, except for BMI, suggests the conclusions may be extended to larger samples. A major limitation to the study was an inability to accurately backdate the time of infection in women with spontaneous abortion.
“[O]ur study provides reassuring findings for women who intend to become pregnant during the SARS-CoV-2 pandemic or who became infected during their first trimester of pregnancy,” investigators concluded, adding that there is a “favorable maternal course at the beginning of pregnancy, consistent with” previous trials.
Cosma S, Carosso AR, Cusato J, et al. COVID-19 and first trimester spontaneous abortion: a case-control study of 225 pregnant patients. Am J Obstet Gynecol. Published online October 8, 2020. doi: 10.1016/j.ajog.2020.10.005.