True or False: Pregnancy is the most common cause of secondary amenorrhea.

The statement that pregnancy is the most common cause of secondary amenorrhea is true. Secondary amenorrhea is defined as the absence of menstruation for three or more cycles in a woman who has previously had regular menstrual periods. One of the most significant and prevalent reasons for this condition is pregnancy, as it leads to a natural cessation of menstruation.

In the reproductive age group, the likelihood of pregnancy occurring is high, making it a primary consideration in the differential diagnosis when a woman presents with amenorrhea. Other causes of secondary amenorrhea do exist, such as hormonal imbalances, stress, significant weight changes, and underlying health conditions, but they are less common than pregnancy in the general population of women who are of childbearing age. It is important for healthcare providers to confirm or rule out pregnancy as the first step when assessing secondary amenorrhea.