Department of Medical Laboratory Sciences and Technology, Division of Clinical Pharmacology, Karolinska Institutet, Karolinska University Hospital (Huddinge), Stockholm, Sweden. helena.karypidis@ki.se
OBJECTIVE: To determine whether the cytochrome P450 1B1 (CYP1B1) Val432Leu polymorphism is associated with risk of miscarriage. We also analyzed the possible interaction between this polymorphism and caffeine intake. DESIGN: The population-based case-control study included 507 women with miscarriage in the first trimester of pregnancy and 908 controls with a normal first-trimester pregnancy. The controls were frequency matched to cases. The material was analyzed taking maternal age, smoking habits, alcohol intake, caffeine intake, fetal karyotype, nausea, and vomiting into consideration. SETTING: University hospital and primary care facility. MAIN OUTCOME MEASURE(S): CYP1B1 Val432Leu genotype frequencies in cases and controls. RESULT(S): Carriers of the CYP1B1 432 Val/Val genotype were at a higher risk of miscarriage in the first trimester of pregnancy (odds ratio = 1.46; 95% confidence interval, 1.02-2.08). We also found a significant interaction between genotype and caffeine intake. CONCLUSION(S): CYP1B1 Val432Leu polymorphism is associated with first-trimester miscarriage, and it may also modify the risk among coffee drinkers.