Pre-eclampsia is the development of hypertension after the 20th week of pregnancy in a woman who previously had normal blood pressure.

In pre-eclampsia, the blood vessels of the placenta remain narrow as there aren't enough cells for invasion.

The sFlt-1 protein is partly responsible for vessels not developing normally, leading to an increase in blood pressure as there is limited space in which the blood flows.

There are now higher levels of the protein sFlt-1 in the maternal blood than the proteins involved in normal vessel formation.

We assume that in the case of women with HIV, an additional factor interferes with the normal development of blood vessels.