BACKGROUND

To characterize the prevalence of orofacial cleft malformations and investigate variations in prevalence according to maternal and infant characteristics, we analyzed a cohort of 298,138 live births delivered between 1987 and 1990 to residents of Washington State.

METHODS

Infants with cleft defects were identified using a statewide, population-based birth defects registry. Information on infant and maternal characteristics was obtained from Washington State birth certificates. Multiple logistic regression analysis was used to measure the association between potential risk factors and orofacial clefts. Cleft lip with or without cleft palate (CL +/- CP) and cleft palate (CP) were analyzed separately, depending on the presence or absence of other defects.

RESULTS

We identified 608 infants with cleft defects. The prevalences of isolated and non-isolated CL +/- CP were 0.87 and 0.30 per 1,000 live births, respectively. The prevalences of isolated and non-isolated CP were 0.34 and 0.54 per 1,000 live births, respectively. Compared with mothers aged 25-29 years, mothers aged < 20 years were twice as likely to have an infant with isolated CL +/- CP (RR = 2.0; 95% CI 1.3, 2.9). Compared to white mothers, black mothers were more likely to have an infant with non-isolated CL +/- CP (RR = 2.8; 95% CI 1.2, 6.6).

CONCLUSIONS

The prevalences of orofacial clefts in Washington State in 1987-90 were similar to those of other states. This study is among the first to report a greater relative risk for isolated CL +/- CP among the infants of mothers < 20 years compared to older mothers.