This invention relates to materials and methods associated with polymorphic variants in two enzymes involved in folate-dependent and one-carbon metabolic pathways important in pregnancy-related complications and neural tube birth defects: MTHFD1 (5,10-methylenetrahydrofolate dehydrogenase, 5,10-methenyltetrahydrofolate cyclohydrolase, 10-formyltetrahydrofolate synthase) and methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 1-like (MTHFD1L). These enzymes are extremely important in the promotion of DNA synthesis, a process that is critical for normal placental and fetal development.

Recently, the inventors have discovered that a MTHFD1 polymorphism is also a maternal genetic risk factor for placental abruption, premature separation of a normally implanted placenta. This polymorphism may also be a risk factor for first and second trimester miscarriages. Diagnostic and therapeutic methods are provided in this invention involving the correlation of polymorphic variants in MTHFD1 and MTHFD1L and other genes with relative susceptibility for various pregnancy-related and other complications such as cancer, cardiovascular disease, developmental anomalies and psychiatric illnesses. Both nutrient status and genetic background are independent yet interacting risk factors for impaired folate metabolism. However, the mechanisms that lead to pathology or the mechanisms whereby folate prevents these disorders are unknown. Therefore, a diagnostic and therapeutic invention of this kind would significantly improve the detection and treatment of disorders associated with folate metabolism.