Objective. COVID-19 vaccination has a reduced efficiency against the Omicron variant. The aim of this study was to assess the clinical impact of COVID-19 vaccination on maternal and perinatal outcomes during the Omicron wave. Materials and Methods.This was an observational multicenter study, pregnant women who gave birth while infected by SARS CoV2 during the Omicron waves were included.Patients with incomplete vaccination and recurrent infections were excluded. Patients were divided into 2 groups: the Vaccinated Group included pregnant women with completed vaccination (≥ 3 doses of mRNA vaccine or 2 doses ≤ 6 months); the Non-vaccinated Group included pregnant women who had no COVID-19vaccination. Data about obstetrical and fetal outcomes in both groups were compared.Results. In total, 59 vaccinated and 49 unvaccinated patients were included. The incidence of patients requiring oxygen support was reduced from 36.7% to 1.7% with p < 0.001. The mode of delivery was comparable in both groups. The need for referral to an intensive care unit was reduced from 22.4% to 1.7% with p ≤ 0.001. The length of hospitalization was reduced from 6.8 ± 5 to 2.8 ± 2 days, with p ≤ 0.001. The prematurity rate was comparable in both groups, but the need for neonatal intensive care admission was reduced from 22.4% to 4.1% with p = 0.019. Conclusions.The COVID-19 vaccination seems to be efficient during the Omicron waves. Obstetrical and neonatal outcomes were improved with complete vaccination. Pregnant women should be advised to have a complete vaccination status.

Material and Methods. This was an observational multicenter study. Pregnant women who gave birth while infected by SARS CoV2 during the Omicron waves were included. Patients were divided into 2 groups: the "booster vaccination" group included pregnant women who had completed vaccination and had received an additional dose of vaccine during pregnancy; the "non-booster vaccination" group included pregnant women who had completed primary vaccination without booster shots. Data about obstetrical and neonatal outcomes in both groups were compared.Results. In total, 59 patients were included: 41 received booster shots during the current pregnancy, and 18 did not. Asymptomatic forms were seen in 58.5% of the "booster vaccination" group versus 16.6% of the "non-boosted vaccination" group with p = 0.003. The need for cesarean delivery was reduced from 72.2% to 41.4% with p = 0.028. The length of hospitalization was reduced from 4.67 ± 4 days in the "non-boosted vaccination" group to 1.98 ± 0.93 days in the booster vaccination group with p = 0.001. The booster vaccination allowed reduced rates of prematurity with p = 0.011 and neonatal intensive care admissions with p = 0.007. Conclusions.The COVID-19 booster vaccination seems to be beneficial during the Omicron waves. It improved obstetrical and neonatal outcomes. So, pregnant women could be advised to get a booster dose of the COVID-19 vaccine when they get pregnant.