Characteristics of 2733 cases diagnosed with deformational plagiocephaly and changes in risk factors over time.

OBJECTIVES To describe infant and maternal characteristics among infants with plagiocephaly and to quantify time trends in potential risk factors for plagiocephaly. DESIGN Case-only study. We described the characteristics of individuals born between 1987 and 2002. We also compared characteristics of individuals born from 1987 through 1990, before the American Academy of Pediatrics 1992 sleep-position recommendations, with those of individuals born from 1991 to 2002. SETTING Children's Craniofacial Center at Children's Hospital and Regional Medical Center in Seattle, Washington. PARTICIPANTS Subjects included 2733 infants diagnosed with deformational plagiocephaly or brachycephaly before 18 months of age who were born from 1987 to 2002. MAIN OUTCOME MEASURE Descriptive statistics, odds ratios, and 95% confidence intervals. RESULTS Among individuals born from 1991 to 2002, 91.6% had occipital-only flattening, 17.2% were brachycephalic, 67.7% were boys, and 9.9% were multiple birth infants. As compared with individuals born from 1987 through 1990, those born from 1991 to 2002 were more apt to be a multiple birth (odds ratio [OR] 3.4, 95% confidence interval [CI]: 0.8, 14.1) and to have a mother > or =35 years of age (OR, 3.2; 95% CI, 1.4 to 7.3); they were hospitalized less commonly at birth for 4 or more days (OR, 0.02; 95% CI, 0.01 to 0.06). CONCLUSIONS Several risk factors for plagiocephaly were more common among individuals born after the 1992 American Academy of Pediatrics sleep-position recommendations. These results are consistent with the explanation that supine sleeping modifies the association between such risk factors and plagiocephaly. Further studies with a control group are needed to validate this conclusion.