Head-size measurements can help screen for long-term IQ problems in very premature or very low birth weight babies, researchers say.

“Measuring head circumference and thus head growth in early childhood is a proxy measure of brain volume growth in early childhood,” said study senior author Dieter Wolke, of the University of Warwick in England.

Faster growth

It’s “simple and cheap to do and as shown in our research, slow head growth is a specific warning sign for potential neurocognitive problems,” Wolke, a psychology professor, said in a university news release.

The study included about 400 babies born in Germany in 1985–1986 and followed into adulthood. About half were born sooner than 32 weeks’ gestation and/or under 3.3 pounds (1.49kg). The others were born full-term.

The children’s head circumference was checked at birth, five months, 20 months and four years of age. The kids then took intelligence tests at six and eight years, and at 26 years of age.

The very premature/very low birth weight infants had smaller heads at birth, but between birth and 20 months their heads grew relatively faster than that of full-term children because they had to catch up, the researchers said.

Brain volume growth

Study first author Julia Jaekel, of the University of Tennessee, noted that “those who showed faster head growth, whether preterm or term-born, had higher intelligence scores at 26 years”.

In addition, the findings showed that “catch-up head growth was particularly beneficial for intelligence scores in very premature and very low birth weight children. It was a better predictor than how early or at what birth weight infants were born,” said Jaekel.

The results show that head growth reflects brain volume growth and is linked with long-term brain development, according to the researchers.

The study was published in the Journal of the International Neuropsychological Society.

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