Pregnancy complications and poor fetal growth could be predicted by blood test

It could soon be possible to predict the likelihood of pregnancy complications with a blood test. This advance could be on the horizon due to the discovery in expectant mothers of a blood protein that researchers say is a reliable indicator of pregnancy complications and poor fetal growth.

Reported in the journal Nature Genetics, the findings demonstrate that a protein called DLK1 plays an important role in providing energy to the developing fetus. When measured in a mother’s blood, low levels of this protein may signal reduced fetal growth as a result of pregnancy complications.

Although levels of DLK-1 are known to be increased during pregnancy in the blood of rodents and humans, knowledge is scarce about what the protein does. Dr Marika Charalambous from Queen Mary Hospital of London (UK) and her team conducted a series of experiments to clarify this issue.

To do this, the researchers knocked out the DLK1 gene to better understand its function.The team discovered that DLK1 derives from the embryo and that its deactivation halts ketosis, the method by which the body burns fat stores to provide energy in the absence of glucose.

The researchers suggest that this finding indicates that DLK1 is important in the provision of energy to the fetus and therefore fetal growth. In addition, reduced levels of the DLK1 protein in the blood of pregnant mice were associated with lower fetal mass.

The team followed up on this by working with researchers from the University of Cambridge (UK) to examine whether blood levels of DLK1 in pregnant women are associated with fetal health. The team took blood samples at around 36 weeks of pregnancy and found that infants that were small for gestational age were more likely to be born to mothers with low levels of the DLK1 protein than high levels.

This was found to be due to restricted blood flow through the umbilical cord and other pregnancy complications.

“It’s incredibly important to start developing tests that can give an obstetrician much more information on the pregnancy before delivery, so that they can intervene before complications come to crisis point” said Dr Charalambous.

“Measuring DLK1 levels in the mother’s blood could be a reliable and noninvasive way of predicting whether there are likely to be complications, especially those that cause reduced nutrient supply to the baby. In those instances, you really need to get the baby out quickly, so women could opt to have an early elective delivery” She added.

Although promising, the researchers note that further studies are required for a better understanding of the potential of DLK1 as a diagnostic for pregnancy complications.

Sources: Cleaton MAM, Dent CL, Howard M, Corish JA, Gutteridge I, Sovio U et al. Fetus-derived DLK1 is required for maternal metabolic adaptations to pregnancy and is associated with fetal growth restriction. Nature Genetics doi:10.1038/ng.3699 (2016);
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