Preeclampsia is a rare but dangerous complication of pregnancy that affects between 5% and 8% of all pregnancies in the United States. The condition begins in the first trimester but no discernible symptoms are evident until the third trimester. Early detection usually brings the most positive outcomes and a new Norwegian study may lead to diagnosis even before symptoms arise.
In preeclampsia, the placenta doesn't develop sufficiently during the first trimester but few, if any, symptoms are produced. An exaggerated response from the woman's immune system is thought to trigger the reaction.
Later, however, usually in the third trimester, high blood pressure (hypertension) and high protein levels in the urine (proteinuria) reveal the disease. Complications include restricted fetal growth, preterm delivery, and an increased risk that mother and child will develop cardiovascular disease later in their lives.
The Norwegian researchers explored the disease at the molecular level, using nuclear magnetic resonance (NMR) spectroscopy and other technologies to analyze blood and urine samples from three groups of women.
The NMR technology allowed the research team to examine molecular weight metabolites. This technology — metaolomics — measures the substances formed during and after everyday chemical interactions (metabolism). The technology produces a metabolic profile for assessment of a person's state of health.
According to the study's lead author, Marie Austdal, of the NTNU, when the metabolisms of the women in the study were compared, the metabolism is clearly different when preeclampsia is diagnosed. Austdal describes the metabolic difference to be similar to that of cardiovascular disease; both conditions produce inflammation that can be measured in the urine and blood.
The research team used various means to analyze blood and urine samples of 30 women. The women were divided into three groups, with two controls:
- Women diagnosed with preeclampsia
- Women pregnant but not preeclamptic (control group)
- Women not pregnant (control group)
The preeclamptic women were matched by age with a woman in each of the control groups and by gestational age with a woman in the pregnant control group.
Three clearly different metabolic profile groups were revealed. Nine metabolite variances were found in the urine of the preeclamptic group that were not found in the pregnant control. The preeclampsia group was found to have higher levels of low- and very-low-density (LDL / bad) lipoproteins and lower levels of high-density (HDL / good) lipoproteins than the two control groups.
"This abnormal metabolism may be present earlier, so that the disease may be predicted before onset," said Austdale. The researchers next project will involve women in early pregnancy. The researchers hope to identify biomarkers before symptoms develop so management can begin earlier in pregnancy.
Source: Austdal, Marie, et al. "Metabolomic Biomarkers in Serum and Urine in Women with Preeclampsia." PLOS One. PLOS. Mar 17, 2014. Web. Mar 30, 2014.