An epidemiologic longitudinal study of sleeping problems and feeding experience of preterm and term children in southern Finland: comparison with a southern German population sample.

Objective: To determine the influence of breast-feeding on the prevalence and persistence of sleeping problems in southern Finland (SF) and southern Germany (SG).

Design: Prospective binational population study of infants admitted to special care units (SCUs) in geographically defined areas in SF and SG.

Subjects: In SF, the number of SCU infants was 1057 (very preterm, 47; preterm, 258; term, 752); 485 term infants were control subjects. In SG, the number of SCU infants was 4427 (very preterm, 284; preterm, 1419; term, 2724).

Main Outcome Measure: Parent reports of child sleeping problems at 5, 20, and 56 months of age.

Results: Night waking at 5 months of age was less frequent for SCU very preterm (25.5%), preterm (40.6%), and term infants (48%) than for term control subjects (56.7% to 59.9%) in SF. No differences in sleeping behavior according to gestation were found at 20 and 56 months. Sleeping problems were greater in SF infants (25.5% to 48%) than in SG infants (15.1% to 19.1%) at 5 months of age and were explained by a higher rate of breast-feeding in SF. Breast-feeding had no long-term effects on night waking or on co-sleeping in SF. In contrast, breast-fed infants continued to wake more often in SG.

Conclusions: Breast-feeding rather than gestational age is strongly related to night waking. More support for dealing with night waking might prevent early termination of breast-feeding.