Ovulaatioon

Ovulaatioon is the release of a mature oocyte (egg) from a dominant follicle in the ovary as part of the menstrual cycle. It typically occurs about halfway through a cycle but can vary widely among individuals and across cycles. The event is driven by hormonal changes: rising estrogen prompts a surge of luteinizing hormone (LH), which triggers ovulation, after which the corpus luteum forms and secretes progesterone.

Timing and fertility window: Ovulation usually takes place around day 12 to 16 in a 28-day cycle but can occur earlier or later in longer or shorter cycles. The fertile window comprises roughly the five days before ovulation and the day of ovulation itself, because sperm may survive for several days and the ovulated egg remains viable for about 12 to 24 hours.

Signs and detection: Some people notice mittelschmerz (brief lower abdominal pain) at ovulation, and many observe changes in cervical mucus that becomes clear and stretchy. Basal body temperature may rise slightly after ovulation. Home ovulation tests detect the LH surge in urine, while medical ultrasound can confirm follicle rupture.

Variations and health aspects: Not all individuals with female reproductive anatomy ovulate regularly; causes of irregular or absent ovulation include stress, excessive weight change, polycystic ovary syndrome (PCOS), thyroid disorders, or certain medications. Understanding ovulation is relevant for conception, fertility planning, and certain medical evaluations. If cycles are absent, very irregular, or accompanied by severe pain, medical advice may be warranted.