Urinary Analysis in Early Pregnancy Predicts Likelihood of Preterm Birth

Analysis of metabolites in the urine during the early stages of pregnancy was found to be an effective approach for predicting the likelihood of a preterm birth.

Preterm birth (PB) and fetal growth restriction (FGR) convey high risk of infant mortality and morbidity, as well as increasing the chance of developing chronic disease in later life. Biomarkers identified early in pregnancy could predict poor birth outcomes and aid in their prevention and management.

Investigators at Imperial College London (United Kingdom) and the University of Crete (Greece) used proton nuclear magnetic resonance spectroscopy to analyze metabolites in urine samples obtained at the first ultrasound appointment from 438 pregnant women in the Rhea cohort. The Rhea cohort is a large population case-control mother-child study that started in Crete in 2007.

Results revealed that elevated urinary levels of lysine were associated with spontaneous premature birth. Decreased levels of acetate, formate, tyrosine, and trimethylamine were associated with poor fetal development. Women with decreased levels of these urine metabolites also showed signs of an increased risk of diabetes, such as higher blood insulin. Increased levels of an N-acetylated glycoprotein were significantly associated with induced preterm birth (IPB) in overweight and obese women only.

Senior author Dr. Hector Keun, senior lecturer in biological chemistry at Imperial College London, said, "While we know that metabolism in the mother changes substantially during pregnancy to help supply the growing fetus with nutrients, we were surprised to see so early in pregnancy a link between metabolites that we could easily detect in a urine sample and low birth weight. Our findings imply that it could be possible to improve the identification of women at higher risk of delivering smaller babies or premature delivery using noninvasive metabolic profiling technology early in pregnancy. Future investigation of the factors that produce the molecules associated with these pregnancy outcomes should improve our understanding of the genetic and environmental factors that influence restricted fetal growth and thus help us to reduce the likelihood of these events. We will also go on to test if exposure to these metabolites during pregnancy has a lasting impact on child development after birth."

The urine metabolites study was published in the July 11, 2014, online edition of the journal BMC Medicine.


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Imperial College London

University of Crete