Objective To explore the clinical manifestations, risk of maternal-infant vertical transmission, as well as prevention and control of infection in pregnant patients with SARS-CoV-2 Omicron variant infection in a tertiary first-class hospital during later stage of pregnancy. Methods Clinical features, puerperae and infant outcomes as well as infection prevention and control measures of 3 pregnant women with SARS-CoV-2 Omicron variant infection and their newborns delivered in a tertiary first-class hospital were retrospectively analyzed. Results The average age of 3 pregnant women with SARS-CoV-2 Omicron variant infection was 29 years old and the average gestational age was 38⁺⁴ weeks. The initial clinical symptoms of 1 case were cough and expectoration, and the other 2 patients had no clinical manifestations of coronavirus disease 2019. All patients terminated their pregnancy with cesarean section, and the maternal milk, vaginal secretion, umbilical cord blood and amniotic fluid were tested for SARS-CoV-2 nucleic acid, results were all negative. The mother and baby were separated immediately after the delivery of the newborn, 2 newborns were transferred to isolation room of neonatal intensive care unit for treatment, SARS- CoV-2 nucleic acid test was performed daily during hospitalization, results were all negative; the third case had negative nucleic acid results for two consecutive times at an interval of 24 hours, and was transferred to isolation location for observation. The prognosis of parturients and neonates were good. Conclusion Evidence of maternal-infant vertical transmission of SARS-CoV-2 Omicron variant infection during late pregnancy was not found in this study. For pregnant women with full-term pregnancy or with aggravated respiratory symptoms, it is recommended to terminate the pregnancy in time. After delivery, the mother and baby should be separated and strictly isolated to ensure the safety of the newborn.