LAUSR

COVID-19 Vaccination During Pregnancy— Multiple Pregnancies Need More Focus To the Editor We read the article by Goldshtein et al.1 Using a population-based cohort, the authors studied the association of COVID-19 vaccination during pregnancy with adverse neonatal and early infant outcomes. The study validated the safety of BNT162b2 messenger RNA vaccination during pregnancy in newborns, which could potentially be delivered to many people with singleton pregnancies on a worldwide scale. However, infants born from multiple pregnancies were excluded because the relatively small number did not allow adjusted or stratified analysis. The incidence of multiple pregnancies is approximately 3% worldwide,2 meaning that there are millions of new multiple births worldwide every year. Compared with singleton pregnancies, multiple pregnancies are associated with a 2to 4-fold risk of maternal or neonatal death.3 A recent national cohort study indicates that multiple pregnancies are more frequently associated with COVID-19 diagnosis (0.7% vs 0.4%).4 Among all pregnant persons, COVID-19 infection is associated with an increased risk for maternal mortality or severe morbidity.5 Thus we have reason to believe that multiple pregnancies would be at increased risk of maternal or neonatal death compared with singleton pregnancies or the general population if combined with COVID-19 infection. The vulnerability and susceptibility of pregnant individuals and infants entail enhanced protective strategies against COVID-19. COVID-19 vaccines have proven safe and effective in reducing morbidity and mortality in the general population. However, to date, there are few population-based studies on the safety of vaccination in populations with multiple pregnancies, mainly because pregnant people have not been recommended for COVID-19 vaccination in most countries. In Israel, all pregnant individuals have been encouraged to receive the vaccine.1 Studies from Israel on vaccination safety in pregnant people—especially in those with multiple pregnancies, who are more vulnerable to COVID-19, and their offspring— are significant. Therefore, it would be beneficial if the authors could provide valid results of the association of COVID-19 vaccination during multiple pregnancies with adverse neonatal and early infant outcomes. More importantly, a future study with more participants with multiple pregnancies is urgently warranted using a well-established database.