RESUMEN
OBJECTIVE: To asses the association between intake of folate and B vitamins and the incidence of spontaneous abortion (SA) according to the maternal methylenetetrahydrofolate reductase (MTHFR) polymorphisms (677 C>T and 1298 A>C). MATERIAL AND METHODS: We conducted a nested case-control study within a perinatal cohort of women recruited in the state of Morelos, Mexico. Twenty-three women with SA were compared to 74 women whose pregnancy survived beyond week 20th. Intake of folate and B vitamins respectively, was estimated using a validated food frequency questionnaire. Maternal MTHFR polymorphisms were determined by PCR-RFLP and serum homocysteine levels by HPLC. RESULTS: Carriers of MTHFR 677TT and 1298AC genotypes respectively showed an increased risk of SA (OR 677TT vs. CC/CT=5.0; 95 percent CI: 1.2, 20.9 and OR 1298 AC vs. AA=5.5; 95 percent CI: 1.1, 26.6). CONCLUSIONS: Our results support the role of MTHFR polymorphisms as a risk factor for SA, regardless of dietary intake of B vitamins.
OBJETIVO: Evaluar la asociación entre aborto espontáneo (AE) y el consumo dietético de vitaminas B en mujeres mexicanas portadoras de los polimorfismos de la metilentetrahidrofolato reductasa (MTHFR) (677 C>T y 1298 A>C). MATERIAL Y MÉTODOS: Mediante un diseño de casos y controles anidados en una cohorte, se comparó la ingesta dietética materna de vitaminas B y folato, los polimorfismos maternos de la MTHFR y la concentración sérica de homocisteina de 23 casos de AE (< 20 semanas) y 74 controles (mujeres con embarazos > 20 semanas). RESULTADOS: Las portadoras de los genotipos MTHFR 677TT y 1298AC presentaron un incremento significativo en el riesgo de AE (RM 677TT vs. CC/CT=5.0; IC 95 por ciento: 1.2, 20.9 RM 1298 AC vs. AA=5.5; IC95 por ciento: 1.1, 26.6), respectivamente. CONCLUSIONES: Nuestros resultados apoyan el papel de la mutación de la MTHFR como posible factor de riesgo para el AE, independientemente del consumo de vitaminas B.