Asymptomatic carriage of COVID-19 in pregnant women: a retrospective
cohort study
Abstract
OBJECTIVE Asymptomatic carriage of COVID-19 in pregnant women has been
reported. We sought to ascertain the impact of high quality rapid PCR
testing for COVID-19 in an unselected cohort of pregnant women attending
our maternity unit. DESIGN Retrospective cohort analysis SETTING
Cambridge, East of England POPULATION All pregnant women who were
admitted to Rosie maternity unit over a 4-week period (May to June 2020)
METHODS Pregnant women were screened for COVID-19 using nasopharyngeal
and oropharyngeal swabs on admission. Samples were analysed using the
SAMBA-II RT-PCR machine. Symptoms were defined as cough and/or fever
that could not be attributed to an obstetric cause. RESULTS NP and OP
swabs were obtained from 457/465 women during the study period (98%).
The median turnaround time for results was 5.3 hours (IQR 2.6-8.9). 92%
of results were returned within 24 hours. In our cohort, only one woman
tested positive, giving a screen positive rate of 0.2% (1/457). One
woman who tested negative developed a fever postnatally following
discharge but was lost to follow-up. There was no correlation between
asymptomatic carriage and regional prevalence of COVID-19. CONCLUSIONS
Testing using the SAMBA-II machine was acceptable to the vast majority
of pregnant women requiring admission and had a low turnaround time.
Asymptomatic carriage is low, but not correlated to community prevalence
rates. Screening pregnant women on admission will remain an important
component in order to minimise nosocomial infection and spread within
healthcare workers as COVID-19 rates increase in the UK.