Introduction
The first case of SARS-CoV2 was detected in the UK on
31st January 2020. On the 16th of
March, the UK Government advised pregnant women to ‘shield’, reducing
contact with others as much as possible, prior to a population-wide
‘lockdown’ commencing in the UK on 23rd March.
Although many routine healthcare services in the UK were stopped or
significantly reduced, maternity services have continued throughout the
pandemic, with some modifications to services where feasible. This has
meant that, unlike most people in the population, pregnant women in the
UK have been attending hospitals and other healthcare settings
throughout the pandemic for routine care rather than only for severe
health issues. Therefore, pregnant women may be diagnosed with SARS-CoV2
when they attend hospital because of COVID-19 symptoms, but also may be
diagnosed incidentally when they present for obstetric reasons.
Increasingly, many obstetric units offer routine screening for SARS-CoV2
in all women who are admitted to hospital, with a view to identifying
both symptomatic and asymptomatic patients.
In our unit, swabbing for SARS-CoV2 was initially only recommended for
women with symptoms suggestive of COVID-19, whether or not they attended
because of those symptoms or for other obstetric reasons. These symptoms
included a persistent cough or fever >37.8, with anosmia
added in April 2020. From the week commencing 19th of
April 2020, in line with governmental policy, increases in testing
capacity enabled us to significantly increase the numbers of women
tested. A pilot of surveillance screening of asymptomatic inpatients was
carried out on 22nd of April, alongside commencement
of routine swabbing of all women attending pre-assessment clinics for
planned Caesarean section. A week later, on 29th April
2020, routine swabbing of all maternity admissions began. There are
therefore two screening periods: ‘targeted’ screening prior to
19th April, and ‘enhanced’ screening after the
19th of April.
Here we review the
effect of these different screening strategies, in parallel with UK
government advice to pregnant women, on the numbers of SARS-CoV2 cases
detected within the maternity population at a large obstetric unit
(approximately 7000 deliveries per year) in central London.