Study Shows COVID-19 Vaccination Not Tied to Adverse Pregnancy Outcomes

Study Shows COVID-19 Vaccination Not Tied to Adverse Pregnancy Outcomes

(HealthDay News) — mRNA COVID-19 vaccination during pregnancy is not associated with an increased risk of adverse pregnancy outcomes, according to a study published in the June issue of Obstetrics & Gynecology.

Kimberly K. Vesco, M.D., M.P.H., from Kaiser Permanente Center for Health Research in Portland, Oregon, and colleagues evaluated the association between antenatal mRNA COVID-19 vaccination and risk of adverse pregnancy outcomes. Analysis included 55,591 individuals with singleton pregnancies with live deliveries (June 1, 2021, to Jan. 31, 2022), with data available from eight integrated health care systems participating in the Vaccine Safety Datalink.

The researchers found that 42.3 percent of the cohort received one or two mRNA COVID-19 vaccine doses during pregnancy, with receipt varying by maternal age, race, Hispanic ethnicity, and history of COVID-19. mRNA COVID-19 vaccination was associated with a decreased risk of preterm birth (adjusted hazard ratio [aHR], 0.89; 95 percent confidence interval [CI], 0.83 to 0.94) compared with no vaccination. There was no association between vaccination and small for gestational age (aHR, 1.06; 95 percent CI, 0.99 to 1.13), gestational diabetes (adjusted risk ratio [aRR], 1.00; 95 percent CI, 0.90 to 1.10), gestational hypertension (aRR, 1.08; 95 percent CI, 0.96 to 1.22), or preeclampsia-eclampsia-HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome (aRR, 1.10; 95 percent CI, 0.97 to 1.24).

“This information will be helpful for patients and clinicians when considering COVID-19 vaccination in pregnancy,” the authors write.

Several authors disclosed ties to the pharmaceutical industry.

How does the COVID-19 vaccine affect pregnancy?

The emergence of COVID-19 presented a unique challenge for pregnant women. Pregnancy itself weakens the immune system, making expectant mothers more susceptible to severe illness from respiratory infections. Given the lack of data during initial trials, early concerns swirled around the safety of COVID-19 vaccines for pregnant women. However, mounting evidence now overwhelmingly supports the safety and efficacy of COVID-19 vaccines for expecting mothers and their babies.

Initial anxieties stemmed from the fact that pregnant women were excluded from the initial clinical trials for COVID-19 vaccines. This was a standard precaution to ensure participant safety in a new vaccine. However, researchers anticipated the need to protect this vulnerable population and designed studies to monitor pregnant women who became vaccinated during the trials. Additionally, data on the safety of vaccines in general during pregnancy provided reassurance. mRNA vaccines do not contain live virus and cannot cause infection in the mother or fetus.

Studies on pregnant women and the COVID-19 vaccine

Large-scale studies involving tens of thousands of pregnant women have since been conducted. These studies have found no increased risk of miscarriage, preterm birth, stillbirth, or birth defects associated with COVID-19 vaccination during any trimester. Vaccination during pregnancy may offer some protective benefits to the developing baby. Studies suggest that COVID-19 vaccination during pregnancy can pass antibodies to the baby, potentially offering them some immunity in the early months of life before they can be vaccinated themselves.

Conversely, contracting COVID-19 during pregnancy can pose significant health risks. Pregnant women with COVID-19 are at an increased risk of developing severe illness, including pneumonia and blood clots. They are also more likely to experience complications like preeclampsia, a condition characterized by high blood pressure and damage to other organ systems, and preterm birth. Studies have even shown a possible link between COVID-19 infection and stillbirth.

Should pregnant women get the COVID-19 vaccine?

The Centers for Disease Control and Prevention (CDC) now recommends COVID-19 vaccination for all pregnant women, regardless of trimester. This recommendation is based on the clear evidence of the vaccines’ safety and effectiveness, coupled with the known risks of COVID-19 infection during pregnancy.

Some pregnant women may experience common side effects after vaccination, such as pain, redness, or swelling at the injection site, fatigue, headache, or muscle aches. These side effects are usually mild and short-lived.

Pregnant women, like everyone else, should discuss vaccination with their healthcare provider. The doctor can address any individual concerns and determine the best timing for vaccination during pregnancy.

While research on COVID-19 vaccines is ongoing, the current data overwhelmingly supports their safety and efficacy for pregnant women. Vaccination is the most effective way to protect expecting mothers and their babies from the serious health risks associated with COVID-19 infection.

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