Background and Aim Perinatal factors influencing the hypothalamopituitary axis (HPA) balance have been associated with behavioural disorders later in life. Whether low birth weight due to preterm birth is associated with later eating, sleeping and behavioural disorders has not been evaluated yet.

Design and Methods The study included 105 prepubertal children: 39 born preterm (preterm, <32 weeks), 29 born term but small for gestational age (SGA) and 37 born term with normal birth weight (control). Behavioural histories and blood samples were obtained.

Results Eating, sleeping and behavioural disorders were more frequent in preterm. The incidence, percentage, for eating disorders was 25.6 in preterm, 13.8 in SGA and 5.4 in control; for sleeping disorders 23.1, 10.3 and 2.7; and for behavioural disorders 38.5, 10.3 and 8.1, respectively. Growth hormone, ng/ml, was higher in preterm and SGA compared with control (2.2 ± 3.7, 4.2 ± 6.5 and 1.7 ± 2.7, values in mean ± SD). No differences were found for adrenocorticotrophin hormone, cortisol, prolactin. Leptin, ng/l, was significantly lower in SGA compared with preterm and control (3774 ± 2406, 8714 ± 10 168 and 9432 ± 11 623, respectively). Body mass index (BMI), kg/m², was lower in preterm and/or SGA versus control (17.7 ± 3.0, 16.8 ± 2.5 and 18.5 ± 3.2). In all children with eating disorders leptin levels were lower (1892 ± 1429 versus 8434 ± 10 045) and BMI also (10.6 ± 2.6 versus 12.5 ± 2.3).

Conclusion Children born preterm have a higher risk of developing eating, sleeping and behavioural disorders. No clear association with the HPA axis balance could be found; however, growth hormone levels were higher in children born preterm or SGA. Children with eating disorders were likely to have lower BMI and leptin levels.