Risk factors for deformational plagiocephaly at birth and at 7 weeks of age: a prospective cohort study.

OBJECTIVE The purpose of this work was to identify risk factors for deformational plagiocephaly within 48 hours of birth and at 7 weeks of age. PATIENTS AND METHODS This was a prospective cohort study in which 380 healthy neonates born at term in Bernhoven Hospital in Veghel were followed at birth and at 7 weeks of age. Data regarding obstetrics, sociodemographics, asymmetry of the skull, anthropometrics, motor development, positioning, and care factors related to potentially provoking deformational plagiocephaly were gathered, with special interest for putative risk factors. The main outcome measure at birth and at 7 weeks of age was deformational plagiocephaly, assessed using the plagiocephalometry parameter oblique diameter difference index, a ratio variable, calculated as the longest divided by the shortest oblique diameter of the skull x 100%. A cutoff point of > or = 104% was used to indicate severe deformational plagiocephaly. RESULTS Only in 9 of 23 children who presented deformational plagiocephaly at birth was deformational plagiocephaly present at follow-up, whereas in 75 other children, deformational plagiocephaly developed between birth and follow-up. At birth, 3 of 14 putative risk factors were associated with severe flattening of the skull: gender, birth rank, and brachycephaly. At 7 weeks of age, 8 of 28 putative risk factors were associated with severe flattening: gender, birth rank, head position when sleeping, position on chest of drawers, method of feeding, positioning during bottle-feeding, and tummy time when awake. Early achievement of motor milestones was a protective factor for developing deformational plagiocephaly. Deformational plagiocephaly at birth was not a predictor for deformational plagiocephaly at 7 weeks of age. There was no significant relation between supine sleeping and deformational plagiocephaly. CONCLUSIONS Three determinants were associated with an increased risk of deformational plagiocephaly at birth: male gender, first-born birth rank, and brachycephaly. Eight factors were associated with an increased risk of deformational plagiocephaly at 7 weeks of age: male gender, first-born birth rank, positional preference when sleeping, head to the same side on chest of drawers, only bottle feeding, positioning to the same side during bottle feeding, tummy time when awake < 3 times per day, and slow achievement of motor milestones. This study supports the hypothesis that specific nursing habits, as well as motor development and positional preference, are primarily associated with the development of deformational plagiocephaly. Earlier achievement of motor milestones probably protects the child from developing deformational plagiocephaly. Implementation of practices based on this new evidence of preventing and diminishing deformational plagiocephaly in child health care centers is very important.