Preeclampsia affects one in 15 pregnancies and can result in eclampsia, a life-threatening illness during and shortly after childbirth. The reasons behind the disease remain hotly debated, but new research published in the Journal of Clinical Investigations suggests that babies in utero may have some control in preventing the disease.

Scientists found that unborn babies in pregnant mice released a hormone called adrenomedullin, which can prevent complications during pregnancy such as preeclampsia.

"We've identified the fact that the baby is important in protecting the mom from preeclampsia. If the baby's cells are not secreting this hormone, the mother's blood vessels don't undergo the dilation that they should," said Kathleen M. Caron, PhD, the study's senior author and assistant dean for research at the UNC School of Medicine.

The researchers created mice that produced either more or less than normal levels of the hormone adrenomedullin. The study found that fetuses released adrenomedullin into the placenta during the second trimester alerting immune cells called natural killer cells to help prepare the mother to dilate blood vessels to allow more blood to flow to the placenta.

Researchers may now have the tools to test for adrenomedullin levels and assess a woman's risk of preeclampsia before she becomes ill. The scientists who performed the study are now pursuing testing pregnant women to determine if the same pathway operates in humans.

"We really don't know that a pregnant woman is going to get preeclampsia until she has it... Identifying molecules that could predict preeclampsia would be really important" said Dr. Caron.

Previous studies have found that women who are exposed to semen through unprotected sex multiple times before becoming pregnant were less likely to develop preeclampsia.

The study published in The Journal of Clinical Investigation can be found here.