COVID-19 mRNA vaccination status and concerns among pregnant women in Japan: a multicenter questionnaire survey

BACKGROUND

mRNA vaccination is an effective, safe, and widespread strategy for protecting pregnant women against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, information on factors such as perinatal outcomes, safety, and coverage of mRNA vaccinations among pregnant women is limited in Japan. Therefore, this study aimed to investigate the perinatal outcomes, coverage, adverse effects, and short-term safety of mRNA vaccination as well as vaccine hesitancy among pregnant women.

METHODS

We conducted a multicenter online survey of postpartum women who delivered their offspring at 15 institutions around Tokyo from October 2021 to March 2022. Postpartum women were divided into vaccinated and unvaccinated groups. Perinatal outcomes, COVID-19 prevalence, and disease severity were compared between the two groups. Adverse reactions in the vaccinated group and the reasons for being unvaccinated were also investigated retrospectively.

RESULTS

A total of 1,051 eligible postpartum women were included. Of these, 834 (79.4%) had received an mRNA vaccine, while 217 (20.6%) had not, mainly due to concerns about the effect of vaccination on the fetus. Vaccination did not increase the incidence of adverse perinatal outcomes, including fetal morphological abnormalities. The vaccinated group demonstrated low COVID-19 morbidity and severity. In the vaccinated group, the preterm birth rate, cesarean section rate, and COVID-19 incidence were 7.2%, 33.2%, and 3.3%, respectively, compared with the 13.7%, 42.2%, and 7.8% in the unvaccinated group, respectively. Almost no serious adverse reactions were associated with vaccination.

CONCLUSIONS

mRNA vaccines did not demonstrate any adverse effects pertaining to short-term perinatal outcomes and might have prevented SARS-CoV-2 infection or reduced COVID-19 severity. Concerns regarding the safety of the vaccine in relation to the fetus and the mother were the main reasons that prevented pregnant women from being vaccinated. To resolve concerns, it is necessary to conduct further research to confirm not only the short-term safety but also the long-term safety of mRNA vaccines.

Nationwide survey of fetal myelomeningocele in Japan: Background for fetal surgery

BACKGROUND

Fetal surgery for myelomeningocele (MMC) has yet not been performed in Japan, and the clinical background of fetal MMC in Japan remains poorly described. We examined the prenatal characteristics and perinatal outcomes of fetal MMC to prepare for the introduction of fetal surgery.

METHODS

A nationwide questionnaire survey was conducted with regard to fetuses with MMC between January 2012 and December 2014 at perinatal centers in Japan.

RESULTS

In 50 tertiary centers, 188 cases of MMC were identified, of which 126 (67%) were isolated cases. Only half of the cases involved referral to tertiary centers with a diagnosis of MMC. The median time point for a prenatal diagnosis was 26 weeks' gestation (range, 12-38 weeks); in 54% of cases the diagnosis occurred after 26 gestational weeks, which is over the limit for fetal surgery for MMC. Furthermore, in 22% of cases the diagnosis was made before 22 gestational weeks, and in three-quarters of these cases termination of pregnancy was selected. No fetal or neonatal deaths were observed in the isolated MMC group. MMC repair, ventriculoperitoneal shunt and clean intermittent catheterization were required after birth in 100%, 73% and 55% of isolated MMC cases, respectively. In total, 96% of the tertiary centers cared for <5 cases of fetal MMC per year.

CONCLUSIONS

Gestational age at MMC diagnosis was late mid-gestation, therefore earlier detection is essential when considering fetal treatment of MMC in Japan. Although the survival rate was excellent, in three-quarters of isolated MMC cases ventriculoperitoneal shunt was required. Early detection and centralization of MMC cases at specialized centers should be considered.