Protective effect of hyperemesis gravidarum for nonsyndromic oral clefts

OBJECTIVE: To evaluate whether hyperemesis gravidarum is associated with a decreased risk for nonsyndromic oral clefts and to examine the relationship between hyperemesis gravidarum, birth weight, and gestational age. METHODS: This was a population-based, matched case-control study of 1950 subjects with oral clefts (1368 with cleft lip with or without cleft palate; 582 with cleft palate) collected from the Hungarian Congenital Abnormality Registry and 1955 controls identified from the National Birth Registry. RESULTS: Fewer mothers of newborns with oral clefts had early-onset hyperemesis gravidarum than did mothers of controls (cleft lip with or without cleft palate: 83 cases and 121 controls, odds ratio [OR] = 0.67, 95% confidence interval [CI] 0.50, 0.89; cleft palate: 42 cases and 64 controls, OR = 0.63, 95% CI 0.42, 0.94). The use of dimenhydrinate was more common among mothers of subjects with cleft palate (OR = 2.47, 95% CI 1.11, 5.49), whereas iron seemed to have a protective effect against this condition (OR = 0.26, 95% CI 0.09, 0.80). Gestational age and birth weight were not significantly associated with hyperemesis gravidarum. CONCLUSION: This study suggests that hyperemesis gravidarum provides a protective effect against risk to oral clefts in newborns.