Low Birthweight Increases Risk for Developmental Concerns in Full-Term Infants

Infants born at 37 weeks of gestation with a birthweight below the 25^th percentile demonstrate an increased risk for developmental concerns compared with infants who are not considered small for gestational age (between the 3^rd and 10^th percentiles), according to study findings published in Public Library of Science’s Medicine.

Researchers in the United Kingdom wondered if low birthweight percentiles in infants carried to full-term affected their childhood development.

To answer this question, they conducted a population-based cohort study of 686,284 infants born from 37 weeks’ gestation. They linked information on pregnancy and delivery from the Scottish Morbidity Records from 2003 to 2015 with developmental assessments of the children between ages 2 and 3.5 years.

Child development assessments included Ages and Stages Questionnaires-3 (ASQ-3), Ages and Stages Questionnaire: Social and Emotional-2 (ASQ: SE-2), and the Modified Checklist for Autism in Toddlers (M-CHAT). These outcome measures assessed fine and gross motor control, communication, and social development in these children.

The researchers observed that infants below the 25^th percentile in birthweight after 37 weeks’ gestation showed an increased risk for developmental concerns compared with infants with a birthweight scored between the 25^th and 75^th percentiles.

Infants with a birthweight between the 10^th and 24^th percentiles had an increased risk for developmental concerns (relative risk [RR], 1.07; 95% CI, 1.03-1.12; P <.001). Similarly, infants with a birthweight between the 3^rd and 9^th percentile (RR, 1.18; 95% CI, 1.12-1.25; P <.001) and those lower than the 3^rd percentile (RR, 1.37; 95% CI, 1.24-1.50, P <.001) also had an increased risk.

In contrast, infants whose larger birthweight reached the 75^th to 89^th percentiles (P =.56), 90^th to 96^th percentiles (P =.86), and the 97^th percentile or above (P =.27), did not demonstrate significantly increased risk for developmental concerns.

“Mild to moderate [small for gestational age] is an unrecognized, potentially important contributor to the prevalence of developmental concerns,” the researchers stated. “Closer surveillance, appropriate parental counselling, and increased support during childhood may reduce the risks associated with lower birthweight centiles,” they advised.

Study limitations include the use of the ASQ as a screening tool, the subjective design of developmental assessments, and lack of control for early childhood illness and variables in upbringing that may have also influenced the results.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.