- COVID-19 during pregnancy is associated with an increased risk of adverse health outcomes, including maternal mortality and premature birth.
- Yet vaccination rates in pregnant people remain low because of concerns about the safety of COVID-19 vaccines.
- A major study by Centers for Disease Control and Prevention (CDC) involving over 40,000 pregnant women shows that receiving COVID-19 vaccine during pregnancy did not increase the risk of adverse birth outcomes such as premature birth and smaller-than-normal size at birth.
- This study, along with previous research, suggests that COVID-19 vaccines do not adversely affect the health of pregnant women or newborns.
Pregnant women with COVID-19 are a
This is despite guidance from the
The lower vaccination rate in pregnant women reflects their concerns about the safety of COVID-19 vaccines.
A large CDC study now complements previous research showing that receiving COVID-19 vaccine during pregnancy does not adversely affect neonatal health.
Co-author of the study, Dr Heather Lipkind, a professor at Yale School of Medicine, said, “This CDC study of more than 40,000 pregnant women adds to the evidence that supports the safety of COVID-19 vaccination during pregnancy. This study found that COVID-19 vaccine during pregnancy was not associated with premature or small-for-gestational pregnancy (SGA) when comparing vaccination with unvaccinated. This study adds to the evidence that COVID-19 vaccination is safe during pregnancy. ”
The study appears in the CDC’s weekly journal
The clinical trials that researchers conducted to test the safety and efficacy of COVID-19 vaccines did not include pregnant people.
However, subsequent studies showed no obvious safety concerns related to COVID-19 vaccines on the health of pregnant or newborn babies.
However, many of these studies have involved a small sample or no control group of unvaccinated pregnant individuals.
The present study investigated the effect of COVID-19 vaccination during pregnancy on birth outcomes in addressing these deficits.
To study the impact of vaccination on birth outcomes, the researchers compared premature birth and SGA rates at birth for both vaccinated and unvaccinated pregnant women.
Premature birth refers to the birth of the baby before 37 weeks of pregnancy. In contrast, SGA at birth describes babies who are less or less developed than 90% of newborns of the same pregnancy age. Pregnancy age refers to the duration of pregnancy, starting from the last period of the person.
The researchers examined the effects of vaccination on
The researchers estimated premature birth and SGA on birth rates using birth records and electronic health data from
‘Convincing consequences’ on vaccine safety
The present study included 46,079 pregnant women aged 16 to 49, whose pregnancy was estimated to have started between May and October 2020.
Of the unvaccinated pregnant women, 38.4% were Hispanic, 32.2% white, non-Hispanic, 15.7% Asian, non-Hispanic, and 9.1% Black, non-Hispanic. In the vaccinated pregnant women group, these percentages were: 24.5, 43, 25.6, and 2.7, respectively.
The researchers found that only about 21% of the pregnant women from the study had received at least one dose of the COVID-19 vaccine between December 2020 and July 2021.
Most of them received the Pfizer (54.4%) or Moderna (41.4%) mRNA vaccines, while only 4.2% received the Johnson & Johnson vaccine. Over 98% of these women received the first dose of the COVID-19 vaccine in either the second or third trimester of pregnancy.
After controlling for variables, the researchers found that the incidence of premature birth and SGA at birth was similar in vaccinated and unvaccinated pregnant women.
Furthermore, the trimester when the participant received the first or only COVID-19 dose did not affect the risk of premature births or SGA at birth. Similarly, the number of mRNA vaccine doses individuals received during pregnancy did not influence the incidence of these adverse birth outcomes.
Micro Life B talk to Dr Deshayne Fell, associate professor at the University of Ottawa, Canada. Dr. Fell, who was not involved in the study, “From other studies of [SARS-CoV-2] In the past 18 months, we know that there is an increased risk of premature birth, especially after [SARS-CoV-2] infection during pregnancy. ”
“So, this study by Lipkind et al. provides excellent evidence that COVID-19 vaccination is not associated with premature birth, and this information can be used to help support people’s decisions about COVID-19 vaccination during pregnancy. It is also very encouraging for those who have already been vaccinated during pregnancy. ”
“This well-done study report provides strong evidence against any unforeseen adverse effects of COVID-19 vaccination on birth outcomes. The study is quite large, consisting of a broadly representative population of multiple sites, the analyzes were accurately conducted to account for the time at risk of vaccine uptake, and careful adjustment was made for possible confounding factors. ”
“In terms of the most common adverse birth outcomes associated with premature birth or restricted fetal growth, the results of the study are quite convincing,” said Dr. David A. Savitz.
Dr. Savitz was a professor of epidemiology at Brown University and was not involved in the study.
The study authors acknowledged some limitations of their research. First, its timing meant that only a few women participated in the first three months of pregnancy. As a result, further research is needed to understand the effect of first-trimester COVID-19 vaccination on birth outcomes.
Second, the researchers used the Vaccine Safety Datalink data to identify vaccinated women. And while they had accumulated vaccination data using multiple data sources, the authors noted that some data may have been missed.
An underestimation of the number of women vaccinated could have biased their results.
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