Warwick research suggests smaller gestational size leads to poorer academic performance

Researchers at the University of Warwick have found that babies smaller than expected at birth tend to have poorer school performance as teenagers, the University has shared.

The Warwick researchers worked with the PsychGen Centre at the Norwegian Institute of Public Health, assisted by other collaborating institutions.

The study followed over 92,000 children from infancy until their early teenage years, to examine the relationship between their size at birth and early development, along with their performance in national school tests.

All children in the study were born at full term, ranging from 37 to 41 weeks of pregnancy.

The study found that babies were smaller than expected at birth, as in who weighed less than others of the same sex, earned lower scores in subjects like reading and mathematics.

Those differences persisted into adolescence, indicating a continuing relationship between size at birth and academic scores.

Differences linked to being born slightly earlier within the term period largely washed out by age five, while those linked to being smaller than expected were still apparent in school performance at 14–15 years of age

Xuan Zhao

The study also revealed that babies born by weeks 37–38 had mildly poorer movement and language skills in early childhood than those born between 39–41 weeks. These differences were largely mitigated around the time the children reached schooling age, however, those linked to being smaller than expected were still apparent in school performance during secondary school (ages 14–15).

The findings link to previous research made by the University, when it shared in 2023 that infants with very low birthweight relative to their peers in gestational age were more likely to suffer more developmental issues later in life.

Commenting on the results, Researcher Xuan Zhao from the Department of Psychology, said: “what surprised us was the contrast between the two patterns: differences linked to being born slightly earlier within the term period largely washed out by age five, while those linked to being smaller than expected were still apparent in school performance at 14–15 years of age.”

Professor Dieter Wolke, Professor of Developmental Psychology and Individual Differences added: “For babies born at term, being small for their stage of pregnancy may indicate adverse effects on the brain that affect learning and last into adolescence. However, the long-term effects of being born small may be altered by parenting home stimulation and school support for term born children.”

However, Professor Siobhan Quenby MBE from Warwick Medical School, cautioned: “not every baby born smaller than expected will experience difficulties. However, the study underlines the importance of monitoring a baby’s growth and ensuring that children receive appropriate support as they develop.”