Stillbirths are heartbreaking for families, and around half of these are caused when babies grow too slowly in the womb, known as fetal growth restriction. Slow growth also leads to the live births of babies that are dangerously small, and affects up to 1 in 20 pregnancies. Canadian researchers have found a protein that could lead to a blood test to tag the women and babies most at risk.
The study, published in The Journal of Clinical Endocrinology & Metabolism, used the Ottawa and Kingston (OaK) Birth Cohort to look at a range of biomarkers in women's blood in early pregnancy and found that women with high levels of IGF-binding protein-4 (IGFBP-4) were 22 times more likely to have the smallest babies.
Fetal growth restriction, which seems to be caused by problems with the development of the placenta, is untreatable, but knowing the chances can help doctors to monitor the unborn baby and give it the best opportunities possible, including giving the mother steroids to help the development of the baby's lungs. Even if very small babies make it to full term, they are at risk from other long-term health problems and disabilities in infancy and as adults, including high blood pressure and diabetes. Having a biomarker opens up the chance to create a blood test to find those at risk, and could also lead to routes to prevention and treatment of fetal growth restriction. Andrée Gruslin of the Ottawa Hospital hopes that a blood test could be available in the next few years.
"Usually, we don't find out until later in a pregnancy that a fetus isn't growing properly, but this test can tell us in the first trimester if there's likely to be a problem," says Gruslin. "By identifying these high-risk pregnancies early on, we will be able to monitor these women more closely and hopefully help them deliver a healthier baby."