A systematic review and meta-analysis of 77 international cohort studies (3) showed that pregnant women are less likely to report symptoms of SARS-CoV-2compared to non-pregnant women of reproductive age. However, pregnant women were also much more likely to require ICU admission and mechanical ventilation (OR 1.62 and 1.88 respectively). As with H1N1, women with SARS-CoV-2 were at increased risk of preterm birth requiring neonatal intensive care.There is a strong iatrogenic aetiology to this.
Another review found a 7% ICU admission rate for pregnant women compared with 4.2% for their nonpregnant counterparts. 74% of infections were detected in the third trimester of pregnancy (4), although there will be significant underreporting of asymptomatic and mild cases.
Both studies found risk of severe COVID-19 was increased with maternal age above 35, increased BMI >35, chronic hypertension, and pre-existing diabetes. Of particular note, a high proportion of women with severe COVID-19 were from black and minority ethnic groups. All of these characteristics are consistent with previous maternal mortality reports, and indeed within the non-pregnant COVID-19 population.
We have to be particularly cognisant of this evidence when organising maternity services and assessing pregnant patients. These women should be advised that data shows them to be at particular risk and therefore advised to seek help early if they have any concerns at all.
