anovulace

Anovulace, also called anovulation, refers to the failure to release a mature ovum during a menstrual cycle. When ovulation does not occur, the corpus luteum does not form and progesterone production remains low, which can result in irregular or absent menstruation and infertility. Anovulation is a common cause of menstrual irregularity in women of reproductive age and can be temporary or chronic.

Causes of anovulace are varied and include physiological states such as puberty and perimenopause, and pathological factors affecting the hypothalamic-pituitary-ovarian axis. Common contributors include functional hypothalamic disturbances from stress, undernutrition, or excessive exercise; polycystic ovary syndrome (PCOS); thyroid disorders; hyperprolactinemia; ovarian insufficiency; and certain medications.

Diagnosis relies on history, physical examination, and targeted testing. A pregnancy test is routinely performed to exclude pregnancy. Evidence of ovulation can be sought with mid-luteal progesterone levels, basal body temperature tracking, or ovulation predictor kits. Hormonal evaluations may include LH, FSH, estradiol, prolactin, and TSH. Pelvic ultrasound and assessment for underlying conditions may be indicated, particularly when infertility or additional symptoms are present.

Treatment is tailored to the underlying cause and reproductive goals. For infertility, ovulation induction with agents such as letrozole or clomiphene citrate is common, with gonadotropins used in resistant cases. Metformin may be beneficial in PCOS, and thyroid or prolactin disorders are treated directly. When pregnancy is not desired, cycle regulation can be achieved with combined hormonal contraception. In adolescents, the approach may emphasize observation if spontaneous resolution is likely.

Prognosis depends on the cause and response to treatment. With appropriate management, ovulation can often be restored, but fertility outcomes vary and may require assisted reproductive technologies in some cases.