Infant social withdrawal and rapid infant weight gain

Rapid infant weight gain (RIWG) and infant social withdrawal are important early markers of risk of subsequent overweight/obesity and mental health problems, respectively. While overweight and mental health problems are linked later in life, it remains unclear if this association is present already in infancy.

We examine if infant social withdrawal is associated with subsequent RIWG independently of an array of known risk factors (gestational age, birth weight, sex, parity, breastfeeding, maternal postpartum depressive symptoms, maternal smoking during pregnancy, maternal age at birth and pre-pregnancy BMI, family educational level, and employment status).

In a cohort of 12,468 children born 2015-19 in Copenhagen, we analyzed the association between infant social withdrawal around age 3 months, measured with the Alarm Distress Baby Scale (ADBB)-a validated screening tool, and subsequent RIWG. We retrieved information on social withdrawal and weight during infancy from health visitors' records and linked these to register data. Multivariate logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for RIWG, adjusting for the known risk factors outlined above.

Children showing signs of social withdrawal had 1.19 higher odds of RIWG compared to children showing no signs of social withdrawal (aOR 1.19; 95% CI: 1.03, 1.37, p = 0.017). RIWG was also more likely among boys, firstborns, children born small-for-gestational age, and those with mothers who smoked during pregnancy or had higher pre-pregnancy BMI. In contrast, higher birth weight and breastfeeding >4 months were protective factors. No associations were found with maternal postpartum depression, low education, parental labor market status, or maternal age.

We found an association between infant social withdrawal and subsequent rapid infant weight gain independently of an array of known risk factors, which may expand our understanding of the developmental origins of excess weight gain and its association with early childhood mental health.