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. 2022 Aug 24;1(1):e000190.
doi: 10.1136/bmjmed-2022-000190. eCollection 2022.

Severity of maternal SARS-CoV-2 infection and perinatal outcomes of women admitted to hospital during the omicron variant dominant period using UK Obstetric Surveillance System data: prospective, national cohort study

Hilde M Engjom #  1   2 , Rema Ramakrishnan #  2 , Nicola Vousden  2 , Kathryn Bunch  2 , Eddie Morris  3   4 , Nigel A B Simpson  5 , Chris Gale  6 , Patrick O'Brien  4   7 , Maria Quigley  2 , Peter Brocklehurst  8 , Jennifer J Kurinczuk  2 , Marian Knight  2
Affiliations

Severity of maternal SARS-CoV-2 infection and perinatal outcomes of women admitted to hospital during the omicron variant dominant period using UK Obstetric Surveillance System data: prospective, national cohort study

Hilde M Engjom et al. BMJ Med. .

Abstract

Objectives: To describe the severity of maternal infection when the omicron SARS-CoV-2 variant (B.1.1.529) was dominant (15 December 2021 to 14 March 2022) and describe outcomes by symptoms and vaccination status.

Design: Prospective, national cohort study using the UK Obstetric Surveillance System.

Setting: 94 hospitals in the UK with a consultant led maternity unit.

Participants: Pregnant women admitted to hospital for any cause with a positive SARS-CoV-2 test.

Main outcome measures: Symptomatic or asymptomatic infection, vaccination status by doses before admission, and severity of maternal infection (moderate or severe infection according to modified World Health Organization's criteria).

Results: Of 3699 women who were admitted to hospital, 986 (26.7%, 95% confidence interval 25.3% to 28.1%) had symptoms; of these, 144 (14.6%, 12.5% to 17.0%) had a moderate to severe infection, 99 (10.4%, 8.6% to 12.5%) of 953 received respiratory support, and 30 (3.0%, 2.1% to 4.3%) were admitted to an intensive care unit. Covid-19 specific drug treatment was given to 13 (43.3%) of the 30 women in intensive care. Four women with symptoms died (0.4%, 0.1% to 1.1%). Vaccination status was known for 845 (85.6%) women with symptoms; 489 (58.9%) were unvaccinated and only 55 (6.5%) had three doses. Moderate to severe infection was reported for 93 (19.0%) of 489 unvaccinated women with symptoms, decreasing to three (5.5%) of 55 after three doses. Among the 30 women with symptoms who were admitted to intensive care, 23 (76.7%) were unvaccinated and none had received three doses.

Conclusion: Most women with severe covid-19 disease were unvaccinated and vaccine coverage among pregnant women admitted to hospital with SARS-CoV-2 was low. Ongoing action to prioritise and advocate for vaccine uptake in pregnancy is essential. A better understanding of the persistent low use of drug treatments is an urgent priority.

Trial registration: ISRCTN 40092247.

Keywords: COVID-19; Infectious disease medicine; Obstetrics; Pregnancy complications; Public health.

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Conflict of interest statement

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: MK, MQ, PB, PO’B, and JJK received grants from the NIHR in relation to the submitted work. HME participated in this work as academic visitor to the National Perinatal Epidemiology Unit with funding from the Norwegian Research Council, grant number 320181, and travel grant from the Nordic Federation of Societies of Obstetrics and Gynecology Research fund, grant number 6302. KB, NV, RR, NABS, and CG declare no competing interests. EM is trustee and president of the Royal College of Obstetricians and Gynaecologists, trustee of British Menopause Society and chair of the Board of Trustees Group B Strep Support. PO’B is vice president of the Royal College of Obstetricians and Gynaecologists and co-chair of the Royal College of Obstetricians and Gynaecologists Vaccine Committee.

Figures

Figure 1
Figure 1
Visual abstract. ICU=intensive care unit; PCR=polymerase chain reaction
Figure 2
Figure 2
Inclusion flow chart of pregnant women admitted to hospital with SARS-CoV-2 infection, by admission group in the UK between 15 December 2021 and 14 March 2022
See this image and copyright information in PMC

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