What is the condition characterized by infrequent menstruation with prolonged cycle lengths of greater than 35 days but less than 6 months?

Oligomenorrhea refers to infrequent menstruation characterized by cycle lengths that exceed 35 days but occur less frequently than six months. This condition may arise due to a variety of factors, such as hormonal imbalances, stress, excessive exercise, or weight changes, impacting the normal regulation of the menstrual cycle. It is important to understand that while oligomenorrhea involves infrequent cycles, the term specifically denotes the extended intervals between menstrual periods, which aligns perfectly with the definition provided in the question.

In contrast, amenorrhea refers to the absence of menstruation for three cycles or more and does not encompass prolonged cycle lengths. Polymenorrhagia involves menstrual cycles that occur less than 21 days apart, indicating an overly frequent menstruation, while menometrorrhagia describes irregular and heavy menstrual bleeding. Both of these conditions have distinct characteristics that do not match the definition of infrequent menstruation defined in the question. Thus, the attributes of oligomenorrhea make it the accurate choice.