COVID-19 and maternal and perinatal outcomes.

We echo the call made by Barbara Chmielewska and colleagues1 for better data to capture the effects of COVID-19 on maternal outcomes. Our own systematic review (PROSPERO CRD42020219889, in progress) specifically focuses on the amount of maternal mortality as measured by the maternal mortality ratio, and our findings so far concur with their conclusion of an increase, but we advise caution in the interpretation of this trend.