Maternal and perinatal outcomes in the COVID-19 Omicron wave in comparison with the Delta wave: a multicentre observational study

ABSTRACT

Objective. The aim of the study was to compare maternal and neonatal outcomes of the COVID-19 in Omicron and Delta wave.
Materials and Methods. In this prospective observational multicentre study, we included unvaccinated patients who were hospitalized to deliver and who gave birth while infected. Patients who gave birth from May 15, 2021 to November 15, 2021 were allocated to the Delta group and those who gave birth from November 15, 2021 to the June 01, 2022 were included in the Omicron group.
The maternal and foetal outcomes were compared between the two groups. The significance level was set at p < 0.05.
Results.  We included 84 patients in the Delta group and 45 patients in the Omicron group. We noted more asymptomatic COVID-19 (p = 0.001), less dyspnoea (p = 0.021), and less need for oxygen (p = 0.008) in the Omicron group. Caesarean section delivery was seen in 62 patients from the Delta group, and vaginal delivery was seen in 20 patients from the Omicron group with p = 0.029. Even if the incidence of complications and clinical deterioration after delivery were comparable in both groups, the length of hospital stay and the number of deaths were significantly higher in the Delta group with p = 0.038 and p = 0.024, respectively. The fetal outcomes were comparable.
Conclusions. SARS-CoV-2 infection during the Omicron wave had a lower requirement for oxygen support and improved maternal outcomes in comparison with the Delta wave.