During the COVID-19 pandemic, above all before vaccines were available, an alarm was sounded regarding a possible correlation between severe cases of COVID-19 in pregnant women and preeclampsia, a condition characterized by high blood pressure (hypertension) in the expectant mother and high levels of protein in her urine (proteinuria). It can entail dangerous complications for mother and baby. Preeclampsia was more frequent in pregnant women infected by SARS-CoV-2 and was associated with a heightened risk of complications and death.

Differential diagnosis was a major clinical challenge at the time. While gestational preeclampsia, which is most frequent in the third trimester, elevates the risk of kidney and liver failure as well as causing placental dysfunction and high blood pressure, so does severe COVID-19, owing to the exacerbated inflammation caused by the virus. The protocols for treating the two conditions are different.

In the case of preeclampsia, the pregnancy must be interrupted and the baby delivered as soon as possible by cesarean section, whereas in a woman with COVID-19 the pregnancy can proceed, with clinical support until the infection improves. Assuring a correct diagnosis was even more important in severe cases of preeclampsia (known as HELLP syndrome), especially before the 34th week of pregnancy. Three years after the most lethal period of the pandemic, a review of the scientific literature supported by FAPESP and published in the American Journal of Repr.