What test is commonly used to check for ovulation in females facing infertility?

The luteal-phase progesterone level is a widely accepted method for assessing ovulation in females experiencing infertility issues. This test is pivotal because it measures the level of progesterone in the blood during the luteal phase of the menstrual cycle, typically about one week after ovulation occurs. A significant increase in progesterone levels is indicative of normal ovulation, as the hormone is secreted by the corpus luteum after an egg is released from the ovary.

In cases of infertility, understanding whether ovulation is occurring is crucial, and measuring luteal-phase progesterone provides direct insight into the ovulatory function of a woman's ovaries. This information can help fertility specialists determine the underlying causes of infertility and guide appropriate treatment options.

The other tests listed are not primarily used to check for ovulation. The serum haptoglobin test is used to assess for hemolysis or liver disease, while an endometrial biopsy is typically performed to evaluate the uterine lining for abnormalities or conditions such as endometriosis. A stress test is related to cardiovascular assessments and has no relevance to ovulation or fertility evaluation. Hence, the luteal-phase progesterone level stands out as the most relevant and appropriate choice for checking ovulation in this context.