Protein in maternal blood may predict birth complications

A protein found in the blood of pregnant women could be used to develop tests to determine the health of their babies and aid decisions on early elective deliveries, a study reveals. Low levels of the blood marker known as DLK1 can predict poor foetal growth and complications in pregnancy, and could be used as a non-invasive prenatal diagnostic, the study suggested.

"Measuring DLK1 levels in the mother's blood could be a reliable and non-invasive way of predicting whether there are likely to be complications, especially those that cause reduced nutrient supply to the baby," said Marika Charalambous, researcher at the Queen Mary University of London.
DLK1 is a protein that is found in high levels in the mother's blood during pregnancy, in humans and rodents. But little has been known about its source, what it does, and whether it can indicate anything about the health of a foetus.

The study published in the journal Nature Genetics initially used mice experiments that involved knocking out the gene in either the foetus or the mother, and then measuring the mother's DLK1 level to determine its source. The researchers found that the protein originates from the embryo which means that its levels in maternal blood could provide a direct readout of the embryo's biological state.

The researchers studied 129 first-time mothers, taking measurements of DLK1 levels in their blood and recording the outcomes of their pregnancies. They found that low DLK1 levels were associated with reduced growth of the foetus resulting from pregnancy complications, including poor blood flow through the umbilical cord. The team then looked at how DLK1 affects the metabolism of a pregnant mouse.

When fasting for 24 hours, humans start a process known as 'ketosis', which is what the Atkins diet is based on, and involves burning the energy from fat stores to keep the body functioning. When DLK1 was inactivated in pregnant mice, their fasting response was impaired by not being able to begin ketosis. This indicated the importance of DLK1 in providing energy for the foetus and their growth, and DLK1 levels in the mother were found to be a good predictor of the mass of their offspring.