Omicron in a regional obstetrics department.

The Omicron variant is now predominant, and compared to the delta variant has a lower risk of severe disease in pregnant women. We are unaware, however, of studies that report the rate of infection in consecutive pregnant females presenting for delivery and the effect on the newborn at birth. We did antigen testing in 470 consecutive women who presented to the department for delivery using a rapid microfluidic immunofluorescence assay (SARS‐CoV‐2 Ag, LumiraDx, Alloa, UK). A positive test was confirmed by polymerase chain reaction (PCR) (Xpert® Xpress SARS‐CoV‐2; Allplex™ 2019‐nCoV Assay, Seegene Inc, Seoul, Republic of Korea). Sequencing identified the Omicron variant (BA.1) in over >99% of those with a positive PCR during this period. The study received approval from the hospital's ethics committee without the need for patient informed consent (0069‐21‐LND). A positive antigen test was found in 9.1% (43/470), confirmed by PCR in 35 (not done in the other eight patients). There were no pregnant patients hospitalized during this period because of a COVID‐19 infection. There were seven with minor symptoms (one low‐grade fever, two headache, three dry cough, and one patient with shortness of breath and a headache with a normal oxygen saturation). The frequency of a probable COVID infection had overlapping 95% confidence intervals in those not vaccinated, those vaccinated and those vaccinated and boosted in the last 4 months; 17/176 (9.7%, 5.7%–15.0%), 16/138 (11.6%, 6.8%–18.1%), and 10/156 (6.4%, 3.1%–11.5%), respectively. None of the 43 infected women had preeclampsia, or other acute obstetrical complications, and there were no premature babies small for dates. There was one premature (36 weeks) with a 3080 mg birth weight, and two babies with low birth weights (2280, 2375 mg) delivered at 38 and 39 weeks. None of the 43 babies had an APGAR <7 (0.0%, 0.8–8.2) compared to 14/427–3.3% (1.8–5.4%) of the mothers with negative serology.

We conclude that infection with the Omicron variant was common in patients presenting for delivery. They were mostly asymptomatic or had minor symptoms, and there was no maternal or newborn morbidity. Our findings are consistent with the reports from Texas, Ireland, and Turkey/London where serious disease was uncommonly found. In Ireland, only 32% of those infected were symptomatic, without stillborn, or preterm deliveries.

CONFLICT OF INTEREST

None.