Initial findings of universal screening for SARS-CoV-2 in women admitted for delivery in North Wales: a prospective multicentre cohort study

Abstract

We describe the prevalence of overall and asymptomatic SARS-CoV-2 infection in pregnant women admitted for delivery at three maternity units in North Wales. This was a prospective, multicentre cohort study of universal testing for SARS-CoV-2 infection offered to all pregnant women admitted for delivery. Four hundred and seventy-five women were tested by reverse transcription-polymerase chain reaction of nasopharyngeal swabs with concurrent universal screening for signs and symptoms of COVID-19 infection. The overall prevalence of SARS-CoV-2 infection in pregnant women in North Wales was 2.74% with an asymptomatic prevalence of 1.89%. Sixty-nine percent of infected women were asymptomatic. Pregnant women with SARS-CoV-2 infection are not reliably identified using symptom and temperature screening. The prevalence of maternal infection and asymptomatic carrier rates vary within small geographical regions. It is suggested that a trial period of universal testing may help determine whether such an approach is appropriate for an individual maternity unit.

Impact Statement

• What is already known on this subject? The mean incubation period for SARS-CoV-2 is five days and viral shedding may begin two to three days before the appearance of symptoms. Asymptomatic carriers contribute to transmission of the disease.

• What do the results of this study add? More than two-thirds of infected women were asymptomatic in this study contributing to the body of evidence that most infected pregnant women are asymptomatic. This study provides prevalence data for a rural geographical location in Wales with results similar to an urban London region. There was wide variation in prevalence across three maternity units in a small geographical area ranging from 1.68% to 4.43%.

• What are the implications of these findings for clinical practice and/or further research? This study supports the recommendations of universal SARS-CoV-2 testing for women attending for delivery regardless of symptom status. The results highlight that prevalence of infection amongst pregnant women cannot be assumed based on geographical location or demographics. A trial period of universal testing would establish local prevalence and helps determine whether such an approach is appropriate for an individual maternity unit. Future research could be directed to the prevalence of virus variants in pregnant populations.

Keywords:

• SARS-CoV-2
• COVID-19
• pregnancy
• delivery
• prevalence

Acknowledgements

The authors thank Nia Morris, NHS Librarian and Library Services Manager, John Spalding Library, Wrexham Medical Institute, Wrexham LL13 7YP, Nia assisted with literature search and referencing; Bethan Evans, Labour Ward Clinical Lead Midwife, Wrexham Maelor Hospital, Bethan Evans assisted with data collection at Wrexham Maelor Hospital; Joanna Kelly, Labour Ward Clinical Lead Midwife, Glan Clwyd Hospital, Joanna Kelly assisted with data collection at Glan Clwyd Hospital; Lorraine Gardner, Maternity Matron, Glan Clwyd Hospital, Lorraine Gardner assisted with data collection at Glan Clwyd Hospital; Eleri Pritchard, Labour Ward Clinical Lead Midwife, Ysbyty Gwynedd, Eleri Pritchard assisted with data collection at Ysbyty Gwynedd.

Ethical approval

Ethical approval was not required for this study as it was approved as a clinical pathway. This clinical pathway was approved by the North Wales clinical advisory group. This group was created during the early phase of the COVID-19 pandemic to enable the Health Board to be responsive to the clinical governance requirements to changing clinical pathways and delivery of care. It offered a multidisciplinary clinical consensus on changes to clinical pathways ensuring compliance with the best available evidence.

Author contributions

Hemant Maraj’s roles started at inception of the study and gaining clinical pathway approval at the health board’s clinical advisory group. He was involved in all aspects of carrying out the study, planning, analysing and writing up the final paper. Deepannita Bhattacharjee was involved in developing the clinical pathway, analysing and writing up the paper. Neha Jinsiwale was involved in data collection, maintaining integrity of the data, data analysis and writing up the paper.

Disclosure statement

No author has any interests to declare.

Additional information

Funding

There was no funding for this study.