New WHO international fetal growth charts

A research article published in PLOS Medicine contributes to the evidence base regarding the use of population charts for detection of fetal growth disorders and how best to determine risk of complications.

In the article, Torvid Kiserud from the University of Bergen, Norway, and colleagues establish the World Health Organization fetal growth charts for head and abdominal circumference, length of the thigh bone, and fetal weight using ultrasound measurements during pregnancy.

The researchers included 1,387 healthy women with low-risk pregnancies and unconstrained nutritional and social background from ten countries in Africa, Asia, Europe, and South America, and found that fetal growth showed considerable natural variation, differing significantly between countries, and that fetal growth was to a small extent influenced by maternal age, height, weight, and parity, and by fetal sex.

These findings suggest that WHO charts for growth in estimated fetal weight are more suitable for international use than those commonly applied today, but may need to be adjusted for local clinical use to increase their diagnostic and predictive performance.