A new study by researchers at the University of Oxford, published today in Nature Medicine, identifies fetal head growth patterns that are associated with different developmental, behavioural, visual and growth outcomes at 2 years of age.
The researchers identify, for the first time, a critical time period during pregnancy from 20 to 25 weeks’ gestation that is the starting point for these five growth patterns of the fetal head with different infant outcomes.
This new study provides strong evidence that development in childhood is influenced by events affecting the mother before and/or during pregnancy.
The researchers monitored the growth inside the womb of over 3,500 babies in six countries across the world using serial ultrasound scans throughout pregnancy. The growth and development of those infants was then monitored until the age of 2 years.
José Villar, Professor of Perinatal Medicine at the University of Oxford, who co-led the study said: ‘The strength of our study, conducted in low, middle and high-income countries worldwide, is that we followed the babies from less than 14 weeks’ gestation to 2 years of age using the same methods across all sites, including rigorous quality control measures and international standards for measuring growth and development’.
‘The tools for doing so were produced by the INTERGROWTH-21st Project, which has previously described how fetuses should grow when their mothers are healthy, educated, adequately nourished, free of disease and living in a clean environment’.
The paper describes the work of over 300 researchers that recently completed the INTERBIO-21st Fetal Study involving over 3,500 pregnant women and their babies from Pelotas (Brazil), Nairobi (Kenya), Karachi (Pakistan), Soweto (South Africa), Mae Sot (Thailand) and Oxford (UK).
Aris Papageorghiou, Professor of Fetal Medicine at the University of Oxford, who co-led the study, said: ‘The study is unique because each pregnancy was accurately dated by ultrasound at less than 14 weeks’ gestation and all fetuses were scanned with the same type of ultrasound machine every 5 weeks throughout pregnancy. All the ultrasonographers were trained to measure the growth of the fetuses in a standardised manner’.
‘Much has been said about the importance of the first 1000 days of life in determining future health outcomes. In this study we have shown distinct patterns of fetal head growth during pregnancy and how they relate to infant outcomes. The greatest concern clinically relates to faltering fetal head growth, starting from around 20 to 25 weeks’ gestation, that has the strongest negative effect on cognitive, fine motor, language and visual development at 2 years of age’.
Stephen Kennedy, Professor of Reproductive Medicine at the University of Oxford, who co-led the study, said: ‘This is a landmark study which strongly indicates that prenatal and intrauterine environments determine the growth and development of infants across the world’.
‘Policymakers must take notice of these findings to ensure that mothers enter pregnancy as healthy as possible and receive good, evidence-based care from the first trimester of pregnancy onwards. In future, we hope to identify biomarkers in babies at birth indicative of faltering intrauterine growth of the fetal head as an alternative to having to carry out repeated ultrasound scans so as to determine which newborns might benefit from targeted interventions to improve developmental outcomes’.