Covid-19 vaccine during third trimester of pregnancy not associated with adverse maternal outcomes: BJOG
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) posed major challenges on public health systems. The current evidence suggests that Covid-19 infection in pregnant women is more severe compared to their non-pregnant counterparts, with an increased risk of hospital admission, preterm birth, intensive care unit (ICU) stay, mechanical ventilation, and even death.
Despite the increased risk, and FDA's current deliberation on whether to include pregnant women in clinical trials, pregnant women were not included in the initial COVID-19 vaccine trials. The COVID-19 mRNA vaccines (Pfizer-BioNTech BNT162b2 and Moderna mRNA-1273) currently utilized for mass vaccination do not comprise live vaccines, nor do they use an adjuvant.
Given all of the above, the American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal-Fetal Medicine (SMFM) recommend that COVID-19 vaccines should not be withheld from pregnant and lactating individuals.
The aim of this study carried out by Misgav Rottenstreich and team was to evaluate the Covid-19 vaccination rate (Pfizer-BioNTech BNT162b2) during the third trimester of pregnancy and the impact on adverse maternal and neonatal outcomes.
Women who received two doses of the vaccine were compared to unvaccinated women. Women who were recorded as having disease or a positive Covid-19 PCR swab during pregnancy or delivery were excluded from both study groups. Composite adverse maternal outcomes were reported. Secondary outcomes were vaccination rate and composite adverse neonatal outcomes.
Overall uptake of one or both vaccines were 40.2%, 712 women who received two doses of the Covid-19 vaccine were compared to 1,063 unvaccinated women.
Maternal composite outcomes were comparable between the groups, however, women who received the vaccine had higher rates of elective CDs and lower rates of vacuum deliveries.
An adjusted multivariable logistic regression analysis demonstrated that Covid-19 vaccination was not associated with maternal composite adverse outcome (aOR 0.8; 95% CI [0.61-1.03]); a significant reduction in the risk for neonatal composite adverse outcomes was observed (aOR 0.5; 95% CI [0.36-0.74]).
In terms of safety, the mRNA COVID-19 vaccines are novel in design and, to date, are the first mRNA vaccines to have been comprehensively evaluated for disease prevention in people. Although none of these vaccines contain a virus that replicates, nonspecific side effects from activation of the immune system may occur. Consistently, the Advisory Committee on Immunization Practices (ACIP) branch of the CDC lists pregnancy as a precaution for the administration of these vaccines.
While the findings of the current study are promising, there are several unanswered queries. Maternal and neonatal outcomes of maternal vaccination, during the conception period or early stages of the pregnancy, remain unclear.
In the current study, maternal and neonatal outcomes were found to be similar between groups, with no increase or decrease in adverse outcomes. In author's opinion, the relatively high vaccination rate among pregnant women reflects the high vaccination rate in the population and is related to well-organized and financially supported health care services.
In this multicenter retrospective cohort study, authors found that uptake of Covid-19 vaccination during the third trimester of pregnancy was not associated with an increased risk of adverse maternal outcome and lowered the risk for the adverse neonatal outcome. Further research is required to demonstrate the strengths and limitations of vaccine administration in early ad mid trimester pregnancies for better coverage.
Source: Misgav Rottenstreich et al; BJOG;
https://doi.org/10.1111/1471-0528.16941
