A lot of pregnant women in the United States are given messenger RNA (mRNA), coronavirus 2019 (Covid-19), vaccines. However, data on their safety during pregnancy is limited.
METHODS
We used data from the “vsafe after vaccination health monitor” surveillance system, v-safe pregnancy registry and the Vaccine Adverse Event Reporting System to determine the safety of mRNA Covid-19 vaccines for pregnant women.
RESULTS
There were 35,691 vsafe participants aged 16-54 years old who were identified as being pregnant. Pregnant women reported injection-site pain more often than those who were not pregnant. Headaches, myalgia and chills were less common. There were 3958 participants in the vsafe pregnancy registry. 827 of these were completed pregnancies. 115 (13.9%) were lost pregnancies and 712 (86.1%) were live babies. These were mostly among participants who were vaccinated during the third trimester. Preterm birth was 9.4%, and small size for gestational ages (in 3.2%). No neonatal deaths were reported. While not directly comparable, the proportions of adverse pregnancy outcomes and neonatal outcomes in people who were vaccinated against Covid-19 after a complete pregnancy were similar to those reported in studies that involved pregnant women before the Covid-19 epidemic. The most common of the 221 adverse pregnancy events reported to VAERS was spontaneous abortion (46 cases span>).
CONCLUSIONS
Preliminary results did not reveal any safety warnings among pregnant women who had received the mRNA Covid-19 vaccines. To inform the maternal, infant, and pregnancy outcomes, it is important to do more longitudinal follow up, including a follow-up on large numbers of pregnant women who were vaccinated earlier.
The first available vaccines against coronavirus 2019 (Covid-19), were two messenger RNA (mRNA), vaccines for Pfizer-BioNTech and Moderna. They were approved by the FDA as Emergency Use Authorization (EUA) in December 2020. The FDA granted emergency use authorization (EUA) to the vaccines in December 2020. They were a two-dose series of vaccines, three weeks apart for Pfizer BioNTech and one month apart for Moderna. These vaccines were recommended by the Advisory Committee on Immunization Practices. At authorization, only limited data were available on the safety of Covid-19 vaccines during pregnancy. Only limited human data on safety during pregnancy were available at authorization.
To characterize the safety and efficacy of the new Covid-19 vaccines using mRNA, nanoparticles of lipid, and state-ofthe-art manufacturing methods, pregnant women must be monitored after authorization. It is also important to establish their safety profiles in order to make recommendations for maternal vaccination against Covid-19. We present preliminary results of mRNA Covid-19 vaccine safe in pregnant people from three U.S. vaccination safety monitoring systems: the “vsafe after vaccine health checker” surveillance program,10 the vsafe pregnancy registry11, and the Vaccine Adverse Event Reporting System.12
