Why do we need this research?

The way to check for health problems in the baby and mum during the last three months of pregnancy has hardly changed for a generation or more. One of the main methods still used to check if a baby is growing properly is to measure the mum’s tummy with a tape measure, which is known to be unreliable in identifying babies who are too small.

It is vital to be able to assess risks in pregnancy as accurately as possible in order to give the baby and mum the right care. Using screening methods which do not perform well can result in harm through failing to predict potentially preventable problems, and wrongly classifying low risk women as high risk which then results in unnecessary treatment.

Moreover, progress to develop better healthcare for pregnancies is hampered by lack of understanding of why complications occur. Research often only considers factors that affect the immediate health of mum and baby, overlooking the effects of potential complications on the long-term health of the child.

This research builds on findings from previous work done during the POPS study. This showed that analysis of maternal blood samples helped to identify a blood test that can predict poor growth of the baby in the womb. The research also demonstrated that ultrasound and blood tests which indicate poor growth can predict complications for the baby in the period immediately after birth.

What are the aims of this study?

The ultimate aim of the study is to identify women at the highest risk of complications at a time in their pregnancy where it is still possible to prevent a poor outcome. In order to achieve this, the research seeks to better understand the causes of pregnancy complications and produce tests which are better at predicting such complications. Longer term, the research will aim to explore the relationships between scanning and blood tests in pregnancy and the long-term health and educational attainment of the child.

What will the researchers do?

The study is aiming to recruit 4,500 pregnant women who are undergoing their first pregnancy. The women will have extra scans and blood tests alongside the usual care given during pregnancy so that blood samples can be collected. During the pregnancy, ultrasound scans of the baby and blood flow measurements will be taken. The results of these tests and scans will be recorded and then compared based on the outcome of each pregnancy to work out how well they predict different levels of risk for the baby.     

A crucial part of the study is to compare these results across a wide range of populations to see how well the predictions stand up when tested in different situations. Therefore, the researchers are working closely with other UK university centres (Bristol, Imperial College and University College London) that are sharing data and biological samples from a range of diverse populations.

What does the study expect to find?

From the POPS study which preceded this research, it has been shown that blood tests and ultrasound scans are able to predict problems for the baby during pregnancy to an extent, therefore this POPS2 study aims to show how reliable and accurate these predictions will be over a larger number and more diverse population of pregnant women.

Additional information:

Lead researcher – Professor Gordon Smith

Institution – Cambridge University

Funder – Wellcome Trust

Duration – January 2020 – July 2025

Find out more on the study website.