Research of past decades has shown that pregnancy miscarriage (PM) and placental insufficiency (PI) underlie severe obstetric pathologies that result in complications of fetal development. The occurrence of PI developed during previous PMs varied from 47.6 to 77.3%. Pregnancy miscarriage can be considered to be the clinical manifestation of PI, which is a common complication in women with a previous history of PM. Endothelial dysfunction in the mother and in the fetoplacental complex are basic causes of PI. The angiotensin-converting enzyme (ACE) plays a key role in maintenance of proper balance between vasoconstriction and vasodilatation of blood vessels, and thus, in blood pressure regulation. DNA samples were genotyped for insertion/deletion (I/D) polymorphism of the