Can we improve the detection of fetal growth restriction using the INTERGROWTH 21st chart?


A woman having an ultrasound examIntrauterine growth restriction, the pathological restriction of a fetus’ growth trajectory in utero, has adverse consequences for child health. Accurate in utero identification, and timely delivery of growth restricted fetuses, is critical for minimizing these risks.

In 2014, a high-quality fetal growth chart, the INTERGROWTH 21st chart, was published as a new international standard for monitoring fetal growth. Derived using the same conceptual framework and methodology as the current World Health Organization pediatric growth charts, the fetal growth standard provides a globally-standardized approach for evaluating child growth from “the womb to the classroom”.

Theoretically, the new INTERGROWTH chart has the potential to greatly improve detection of fetal growth restriction worldwide. However, major challenges exist in implementing the standard into clinical care in British Columbia and elsewhere. Most importantly, the relationship between the charts’ percentiles (i.e., size for age) and risks of important child health outcomes has not been defined. As a result, clinicians currently have no guidance on which percentile thresholds on the chart should be used to identify fetuses at increased risk of adverse outcomes due to intrauterine growth restriction. This knowledge gap represents a significant barrier to adopting a potentially valuable new tool into practice.

Data access has been approved for a research project which aims to remove this critical barrier to implementing the INTERGROWTH 21st standard in clinical practice by establishing the association between percentiles on the chart and important child health outcomes, overall and by gestational age.  The project is funded by the BC Children’s Hospital Research Institute.

“Our findings will provide evidence-based guidance on how the chart should be used to differentiate high- and low-risk fetuses in the applied clinical setting,” says project lead, Dr. Jennifer Hutcheon, Associate Professor at the University of British Columbia.

Hutcheon hopes that, with accurate tools for diagnosing growth restricted fetuses, obstetricians will be able to prevent unnecessary preterm delivery and its associated neonatal morbidity and mortality while minimizing risk for fetal death by ensuring a timely delivery for growth restricted infants.

PopData will link data from Perinatal Services BC, the BC Ministry of Health, the BC Vital Statistics Agency and the Human Early Learning Partnership for the project.