Association between a past history of nausea and vomiting during pregnancy and fever after the BNT162b2 COVID-19 vaccination.

Purpose: Nausea and vomiting during pregnancy (NVP) are common among pregnant women and can be severe enough to require hospitalization. However, the mechanism underlying NVP pathogenesis remains unclear. This study examined factors associated with adverse events after vaccination, including a past history of NVP.

Methods: A questionnaire-based survey was completed by non-pregnant women working at Nagasaki University Hospital who received two doses of the BNT162b2 coronavirus disease 2019 (COVID-19) vaccine. This study primarily examined the association between a past history of NVP and post-vaccination fever, as fever was determined to be the most objective and reliable indicator of the surveyed adverse events.

Results: Multivariate logistic regression analysis showed that post-vaccination fever was more strongly associated with a past history of NVP (odds ratio, 1.88; 95% confidence interval, 1.16-3.07) than either age (0.73; 0.56-0.96) or weight (0.85; 0.70-1.15), which were previously considered to be highly associated with the incidence of adverse events following COVID-19 vaccination.

Conclusion: These results suggest an involvement of a similar pathological condition in developing NVP and post-vaccination fever.