COVID-19 vaccination in pregnancy
Lan N Vuong1,2, Minh N Chau2,3, Duy L Nguyen2, Toan D Pham2, Ben W Mol4, Tuong M Ho2,3
1University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
2HOPE Research Center, My Duc Hospital, Ho Chi Minh City, Vietnam
3My Duc Hospital, Ho Chi Minh City, Vietnam
4Department of Obstetrics and Gynaecology, School of Clinical Sciences at Monash Health, Monash University, Melbourne, Victoria, Australia
Dear Editor,
Vaccination has been the most effective strategy against Covid-19 disease caused by SARS-CoV-2. In view of the disruptive nature of the pandemic, vaccines have understandably been approved after shortened assessment trajectories. Pregnant women face more than double the risk of needing admission to an intensive care unit, intensive ventilation, extracorporeal membrane oxygenation and death.1
Early studies on vaccination in pregnant women showed no increased risk of pregnancy complications, but the studies were retrospective and limited to Pfizer-BioNTech.2,3 Here, we compare pregnancy and neonatal outcomes in Vietnamese women vaccinated against COVID-19 with Astra Zeneca and Pfizer-BioNTech.
Methods Between August 2021 and November 2021, 954 pregnant women were offered vaccination against COVID-19 at around 30-31 weeks of gestation at My Duc Hospital, Ho Chi Minh City, Vietnam. The choice for Astra Zeneca or Pfizer-BioNTech vaccines depended on the availability of the vaccines at the time of vaccination. We prospectively investigated the side effects in the vaccinated pregnant women within 1 week after vaccination and followed their pregnancies till deliveries.
Results There were 441 pregnant vaccinated with Astra Zeneca and 513 with Pfizer-BioNTech. Women receiving Pfizer-BioNTech were slightly older, more often multiparous, more often had conceived spontaneously, and more often (80.7% versus 60.1%) had received two doses. There were more side-effects reported after Astra Zeneca, but they were all mild (Table 2).
There were more women with preeclampsia and gestational diabetes mellitus after vaccination with Pfizer-BioNTech as compared to Astra Zeneca (both 1.0% versus 0.2%), but differences were not statistically significant (Table 3). The rate of birthweight <2500 gram was 2.5% after Astra Zeneca and 5.3% after Pfizer (RR 2.1; 95% CI 1.05, 4.18, P-value 0.046). Table 4 shows that this is due to a higher rate of growth restriction and not due to more preterm birth.