This evidence synthesis has been compiled by members of the CITF Secretariat and does not necessarily represent the views of all CITF members.

By Jeanie Quach and Mariana Bego

Findings in recent issues of JAMA Pediatrics and The New England Journal of Medicine suggest pregnant women are more likely to get severely ill from COVID-19 than women who are not pregnant. In addition, pregnant women with COVID-19 are more likely to have premature deliveries and other complications. Preliminary findings also show there the side effects of COVID vaccination in pregnancy are no different than in similarly aged non-pregnant females.

Pregnant women face greater adverse outcomes with COVID-19 infections

Main conclusions:

  • Pregnant women infected with SARS-CoV-2 were at higher risk (compared to non-pregnant women) for many severe complications.
  • Their babies were more likely to be born premature, with lower birth weight and delivered by caesarean section.

With the onset of the COVID-19 pandemic, many pregnant women have been fearful and anxious about having COVID-19, not knowing the outcomes for themselves or their babies. It is now evident that pregnant women infected with SARS-CoV-2 face a much higher risk of severe maternal and newborn complications. In the JAMA Pediatric journal, a multinational study in 18 countries recruited infected pregnant women with COVID-19 from 43 hospitals to assess maternal and neonatal outcomes over time and compared them to non-infected pregnant women.

Pregnant women infected with SARS-CoV-2 were at higher risk (compared to non-infected pregnant women) for many severe complications including high blood pressure causing potential damage to other organs, severe infections, intensive care unit admission, maternal mortality, and preterm birth. Their babies were more likely to be born premature, with lower birth weight and delivered by caesarean section. COVID-19 symptoms including fever, shortness of breath, cough, and chest pain were associated with increased risk of severe complications for infected mothers and their newborns.  This study highlights the importance of further follow-up for infected women and their newborns as long-term health consequences are still unknown.

Villar J, Ariff S, Gunier RB, Thiruvengadam R, Rauch S, Kholin A, Roggero P, Prefumo F, Vale MSD, Cardona-Perez JA, Maiz N, Cetin I, Savasi V, Deruelle P, Easter SR, Sichitiu J, Conti CPS, Ernawati E, Mhatre M, Teji JST, Liu B, Capelli C, Oberto M, Salazar L, Gravett MG, Cavoretto PI, Nachinab VB, Galadanci H, Oros D, Ayede AI, Sentilhes L, Bako B, Savorani M, Cena H, García-May PK, Etuk S, Casale R, Abd-Elsalam S, Ikenoue S, Aminu MB, Vecciarelli C, Duro EA, Usman MA, John-Akinola Y, Nieto R, Ferrazi E, Bhutta ZA, Langer A, Kennedy SH, Papageorghiou AT. Maternal and neonatal morbidity and mortality among pregnant women with and without COVID-19 infection: The INTERCOVID multinational cohort study. JAMA Pediatr. 2021 Apr 22. doi: 10.1001/jamapediatrics.2021.1050.

COVID-19 vaccinations recommended for pregnant women

Main conclusions:

  • No obvious safety signals regarding pregnant women who received mRNA COVID-19 vaccines.
  • The authors recommend a longer follow-up, including among large numbers of women vaccinated earlier in pregnancy to inform more accurate maternal, pregnancy, and infant outcomes.

COVID-19 vaccination has been recommended for pregnant women in many countries, including Canada. The US “CDC v-safe COVID-19 Pregnancy Registry” team recently published their preliminary findings in the New England Journal of Medicine, based on questionnaire responses from over 35,000 v-safe mRNA vaccinated women who self-identified as pregnant. The authors used data collected from mid-December 2020 until the end of February 2021.

Injection site pain was the side effect most frequently reported by pregnant women, whereas it was not a major side effect in non-pregnant women. Other side effects like headache, myalgia, chills, and fever were actually reported less frequently in pregnant women. Although not directly comparable, the proportion of adverse pregnancy and neonatal outcomes reported here appear to be similar to the published incidences in pregnant populations before the COVID-19 pandemic.

This preliminary report does not show obvious safety signals among pregnant women who received mRNA COVID-19 vaccines. However, the authors recommend that more longitudinal follow-up, including large numbers of women vaccinated earlier in pregnancy, is necessary to inform more accurate maternal, pregnancy, and infant outcomes.

As with other participant-reported surveillance systems, the main limitation of this study were potential mistakes in completion of the questionnaires.

Shimabukuro TT, Kim SY, Myers TR, Moro PL, Oduyebo T, Panagiotakopoulos L, Marquez PL, Olson CK, Liu R, Chang KT, Ellington SR, Burkel VK, Smoots AN, Green CJ, Licata C, Zhang BC, Alimchandani M, Mba-Jonas A, Martin SW, Gee JM, Meaney-Delman DM; CDC v-safe COVID-19 Pregnancy Registry Team. Preliminary findings of mRNA COVID-19 vaccine safety in pregnant persons. N Engl J Med. 2021 Apr 21. doi: 10.1056/NEJMoa2104983.