摘要：Objective: To evaluate the possible relationship between preeclampsia and poly morphisms in the main genes involved in folate-homocysteine metabolism. Study d esign: Case-control study: 43 patients with preeclampsia and 122 controls witho ut pregnancy complications. Laboratory studies: tHcy and other amino acids, fola te and vitamin B12 and polymorphisms: 677C >T and 1298A >C(mTHFR); 699C >T, 844i ns68 and 1080C >T (CBS); 2756A >G (mTR); and 66G >A, IVS1+766G >A and IVS1+754 A >C (mTRR). Results: Plasma tHcy and folate values were significantly higher (P = 0.004 and P = 0.019), while met/tHcy ratios were lower (P C polymorphism (mTHFR) with the ratio met/tHcy (P = 0.014); the 699 C >T polymorphism (CBS) with the ratio tHcy/ΣAA (P = 0.013); the 2756A >G polym orphism (mTR) with tHcy (P = 0.034); and the IVS1+766G >A polymorphism (mTRR) w ith hyperhomocysteinem.a.(P = 0.012). Conclusion: An association between the pol ymorphisms analysed and preeclampsia could not be demonstrated.