During the COVID-19 pandemic, pharmacists have had to field a lot of questions from pregnant women who are worried about infection but also have serious concerns about vaccination.

Those worries became more urgent with increasing evidence that pregnant women with COVID-19 are at increased risk for severe illness and adverse birth outcomes, yet many remain reluctant to be vaccinated, according to the CDC.

Now, new data further support the safety of COVID-19 vaccination during pregnancy. A study published in the CDC's Morbidity & Mortality Weekly Report looked at a retrospective cohort of more than 40,000 pregnant women and found that vaccination during pregnancy was not associated with preterm birth or small-for-gestational-age (SGA) at birth overall, stratified by trimester of vaccination, or number of vaccine doses received during pregnancy, compared with unvaccinated pregnant women.

The CDC recommends COVID-19 vaccination for women who are pregnant, recently pregnant, who are trying to become pregnant now, or who might become pregnant in the future. The Yale University–led authors point out, "The absolute risk for severe morbidity associated with COVID-19 in pregnancy is low; however, women with symptomatic COVID-19 during pregnancy have a more than twofold increased risk for intensive care unit admission, invasive ventilation, and extracorporeal membrane oxygenation, and a 70% increased risk for death, compared with nonpregnant women with symptomatic infections."

They also add, "Evidence of the benefits of COVID-19 vaccination during pregnancy continues to accrue, including the detection of antibodies in cord blood. Together, these findings reinforce the importance of communicating the risks for COVID-19 during pregnancy, the benefits of vaccination, and information on the safety and effectiveness of COVID-19 vaccination during pregnancy."

The retrospective cohort study looked at live births from eight Vaccine Safety Datalink healthcare organizations, risks for preterm birth (fewer than 37 weeks' gestation) and SGA at birth (birthweight below the 10th percentile for gestational age) after COVID-19 vaccination (receipt of one or more COVID-19 vaccine doses) during pregnancy.

The authors compared risks for preterm and SGA at birth among vaccinated and unvaccinated pregnant women, taking into account time-dependent vaccine exposures and propensity to be vaccinated. The study included single-gestation pregnancies with estimated start or last menstrual period during May 17, 2020, through October 24, 2020.

Among the 46,079 pregnant women with live births and gestational age available from December 15, 2020, through July 22, 2021, 10,064 (21.8%) received one or more COVID-19 vaccine doses during pregnancy; nearly all (9,892; 98.3%) were vaccinated during the second or third trimester.

Results indicated that COVID-19 vaccination during pregnancy was not associated with preterm birth (adjusted hazard ratio [aHR] = 0.91; 95% CI = 0.82-1.01). In addition, among the 40,627 live births with birthweight available, COVID-19 vaccination in pregnancy was not found to be associated with SGA at birth (aHR = 0.95; 95% CI = 0.87-1.03).

"Results consistently showed no increased risk when stratified by mRNA COVID-19 vaccine dose, or by second or third trimester vaccination, compared with risk among unvaccinated pregnant women," the authors explain. "Because of the small number of first-trimester exposures, aHRs for first-trimester vaccination could not be calculated. These data add to the evidence supporting the safety of COVID-19 vaccination during pregnancy."

In addition to recommending vaccination for women who are pregnant, the CDC urges vaccines for those who are recently pregnant (including those who are lactating), trying to become pregnant now, or might become pregnant in the future.

The content contained in this article is for informational purposes only. The content is not intended to be a substitute for professional advice. Reliance on any information provided in this article is solely at your own risk.

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