Pregnany outcomes

COVID-19 Roundup: Vaccination During Pregnancy, Pregnancy Outcomes, and Gene Variants

Vaccination and Pregnancy Outcomes1

Vaccination against COVID-19 during pregnancy was not associated with an increased risk for preterm birth or small-for-gestational-age (SGA) at birth, according to the results of a recent retrospective cohort.

Included were 46,079 live births from 8 Vaccine Safety Datalink health care organizations, of which 21.8% (n = 10,064) received 1 or more COVID-19 vaccine doses during pregnancy from December 2020 to July 2021. Preterm birth was defined as less than 37 weeks’ gestation, and SGA at birth was defined as a birth weight less than the 10th percentile for gestational age.

The results indicated that COVID-19 vaccination was not significantly associated with preterm birth overall (adjusted hazard ratio [aHR] = .91) or SGA at birth (aHR = .95), compared with unvaccinated pregnant women. There was also no association observed for vaccination by trimester for the first or only vaccine dose.

COVID-19 Infection During Pregnancy2

Individuals with COVID-19 during pregnancy are 2 to 3 times more likely to have certain adverse pregnancy outcomes, according to the results of a national cohort study.

Of the 78,283 pregnancies included, 3.4% (n = 2655) of pregnancies had documentation of a COVID-19 infection. Admission to intensive care, invasive mechanical ventilation, or extracorporeal membrane oxygenation treatment were required in 3.4% of positive patients.

A higher risk of induced abortion, cesarean section, clinician-initiated preterm birth, spontaneous preterm birth, and postpartum hemorrhage were associated with COVID-19 infection during pregnancy. However, the risk of miscarriage, antepartum hemorrhage, and still birth were not associated with infection during pregnancy.

Gene Variant3

A specific gene variant may provide a 20% lower risk of developing severe COVID-19 infection, according to the results of a recent study.

As the gene segment was inherited from Neanderthals in about half of all people outside Africa, the researchers focused their study on individuals of African ancestry without heritage from the Neanderthals. Included were 2787 patients of African ancestry who were hospitalized with COVID-19 and a control group of 130,997 individuals from 6 cohort studies.

The results indicated that 80% of participants of African ancestry carried the variant in question. The result was compared with a prior metastudy of individuals of European heritage.

“This study shows how important it is to include individuals of different ancestries. If we had only studied one group, we would not have been successful in identifying the gene variant in this case,” concluded study author Hugo Zeberg.


—Leigh Precopio



  1. Lipkind HS, Vazquez-Benitez G, DeSilva M, et al. Receipt of COVID-19 vaccine during pregnancy and preterm or small-for-gestational-age at birth – eight integreated health care organizations, United States, December 15, 2020 – July 22, 2021. MMWR Morb Moral Wkly Rep 2022;71(1):26-30.
  2. Regan AK, Arah O, Fell DB, Sullivan SG. SARS-CoV-2 infection during pregnancy and associated perinatal health outcomes: a national US cohort study. J Infect Dis. Published online December 27, 2021. Accessed January 14, 2022.
  3. Protective gene variant against COVID-19 identified. News release. McGill University; January 14, 2022. Accessed January 14, 2022.