A comprehensive analysis has found an increase rate of pre-term births in those with COVID-19 but was otherwise reassuring.
Pregnant women have been deemed to be at a higher risk of severe illness from COVID-19. Moreover, in a systematic review in May 2020, it was concluded that mothers infected with COVID-19 were at an increased risk of pre-term birth although the authors urged caution, as their data were derived from a small number of cases and also included the SARS and MERS viruses. In order to provide as much information as possible on the pregnancy outcomes associated with COVID-19 infection, a team from the Department of Obstetrics and Gynaecology, St George’s University Hospitals NHS Foundation Trust, London, UK, undertook a systematic review of all available literature on COVID-19 and pregnancy in order to provide comprehensive data and to direct the course of ongoing research and studies. They searched all major databases and included a wide range of studies e.g., case reports, case series, and randomised trials, provided that studies reported on women with a PCR-confirmed diagnosis of COVID-19. Extracted information on maternal outcomes including clinical symptoms, laboratory findings, any obstetric complications and perinatal outcomes including death and vertical transmission were also collected.
A total of 86 studies were identified which included 2567 pregnancies. Nearly a third of mothers (30.6%) were older than 35 years and half of the cohort (50.8%) were of Black, Asian or other ethnic minority groups. Overall, antiviral therapy was given to a fifth (21.1%) of women though a much higher proportion (51.15%) received anticoagulation and 18.2% required nasal or non-invasive oxygen support.
COVID-19 symptoms were predominately cough (71.4%), fever (63.3%), dyspnoea (34.4%) and loss of taste or smell (22.9%). The most common laboratory abnormality was a raised D-dimer (84.6%), followed by a raised C-reactive protein or procalcitonin (54%). Fortunately, only 7% of women needed admission to an intensive care unit. Pre-term birth which was primarily iatrogenic was found to be common (21.8%) though this was medically indicated in 18.4% of all cases. The incidence of neonatal COVID-19 infection was low at 1.2%.
Commenting on their findings, the authors noted that generally, pregnancy outcomes were good. The incidence of admission to maternal intensive care was low and likely to be similar to the rates for other non-infected women. Furthermore, there was a very low incidence of maternal mortality. The authors did note how their analysis had several limitations including the retrospective nature of most studies and a lack of standardisation of care, given that studies came from several different countries. While the incidence of vertical transmission appeared to be low, the authors felt that more evidence was needed to confirm whether this represents a significant problem. However, there was a higher-than-average increase in pre-term births which was consistent with findings from other studies.
Khalil A et al. SARS-CoV-2 infection in pregnancy: A systematic review and meta- analysis of clinical features and pregnancy outcomes. EClinicalMedicine 2021