Promising new way to predict older mums’ pregnancy risks

Our stillbirth experts recently published a new study in the medical journal BMC Pregnancy Childbirth which found that measuring placental growth factor (a protein naturally produced in the placenta when it’s working well) and antioxidant capacity (which can show if cells in the placenta are degenerating or inflamed) could help to predict pregnancy risks in the women aged 35 and over.

What did we do?

These latest findings from our Manchester Advanced Maternal Age Study (MAMAS) looked at 527 mums (158 in their twenties, 212 in their thirties and 157 in their forties) across six UK hospitals between March 2012 and October 2014. Our scientists in Manchester compared demographic and medical data with blood samples taken at 28 and 36 weeks of pregnancy.

Researchers matched samples from older and younger mothers with similar characteristics to look for any impact of their age, as well as comparing samples from older mothers with different pregnancy outcomes - including stillbirth, premature birth, babies admitted to neonatal intensive care, and babies born very small or with low Apgar scores (a test of how well the baby coped with birth).

What did we find?

Professor Alex Heazell, our research centre director and the lead author on the new study, explained: “Mothers aged 35 years or over are increasingly common in many countries, and unfortunately having a baby later in life has long been associated with higher pregnancy risks. We already know the changes in oxidative stress and inflammation we saw in this study are associated with many pregnancy complications – but for the first time here, we found they were also present in older mothers, which could be damaging the placenta and might explain why older mothers face these higher risks.

“If we measure these biomarkers in the placenta, along with demographic information and clinical variables that we already know affect pregnancy risk, that could give us a better way of predicting someone’s individual risk of an adverse pregnancy outcome at an older age. However, larger studies are required to see if these markers can be developed into an individual predictive model.”

The study found that placental growth factor could predict 74% of negative outcomes, while antioxidant capacity was accurate 69% of the time. They also found that previous successful pregnancies protected against future problems; mums who had given birth to a live baby before had approximately half the risk of negative outcomes compared to women in their first pregnancies. 

Prof Heazell's team previously found that placentas from mothers over 35 had more abnormalities and changes in function. This new study also adds to evidence on the risks of smoking: mums over 35 who smoked were 4x more likely to have a negative pregnancy outcome.

Why does it matter?

Jane Brewin, our CEO, commented: “This promising new avenue of research has really exciting potential for clinical practice; it could predict older mums’ pregnancy outcomes as early as 28 weeks, so doctors can act to prevent problems for the most vulnerable and avoid unnecessary medical treatment for those with lower risks.

“The tendency to start families later in life now means there’s a real and urgent need for better ways to predict how a mother’s age will affect her pregnancy health. Mums over 35 face higher risks of their babies being born too early, too small, or even stillborn – but if we can identify those in need of help, we can prevent these problems and save babies’ lives.”