This story appears in the March 2018 issue of National Geographic magazine.
Every day hundreds of women die in pregnancy or childbirth. This statistic, which the World Health Organization deems “unacceptably high,” reflects problems in all nations, however prosperous. In the U.S., pregnancy-related deaths have risen steeply in the last two decades.
A primary culprit is a cardiovascular complication called preeclampsia. Marked by high blood pressure, swelling, and elevated protein in the mother’s urine, preeclampsia can be treated but still accounts for many maternal deaths each year—and usually results in premature birth. Worldwide it’s a leading cause of mother and fetal mortality, says Suchita Nadkarni, an immunologist at Queen Mary University of London. Her research aims to find early markers for the illness, which to date is only identifiable in the second or third trimester.
To work toward earlier detection, Nadkarni studies the placenta. The organ grows in a gestating mammal’s uterus to nourish a fetus—but can do that properly only if the immune system is working. When Nadkarni altered that system in mice, vital blood vessels (visible as red on the edges of the five slices on the right half of the image above) became abnormal (four slices on the left).
“Pregnancy is such a bizarre and wonderful thing,” says Nadkarni. “If we can better understand how the immune system functions in that state, then we can ask why it doesn’t work in preeclampsia.”