Ovulation is the release of a mature egg from its developing follicle in the outer layer of the ovary. This usually occurs approximately 14 days before the next menstrual period (the 14th day of a 28-day cycle).
Ovulatory dysfunction or anovulation where an egg is not released from the ovary every month, is the single most common cause of female infertility. Predominantly anovulation is caused by hormonal imbalances such as polycystic ovarian syndrome (PCOS), hypothalamic-pituitary function disorder or ovarian aging can result in failure to ovulate.
Ovulation usually occurs every month of a woman’s life from puberty through to the time of menopause. It is defined as the release of a mature egg from the ovary.
The egg travels down the fallopian tube to meet the sperm. If the egg is fertilized by a sperm, pregnancy is likely to occur. If fertilization does not happen, then menstruation is likely to occur.
The whole process is controlled by two glands in the brain:
- The FSH that is released from the hypothalamus causes the follicles (containing eggs) in the ovaries to mature.
As your body approaches ovulation, an increasing amount of another hormone called estrogen is produced. These high estrogen levels trigger a sudden surge in LH which then leads to the mature egg being released from the ovary. This important step is known as ovulation. Ovulation test may include assessments for:
- Urine Luteinizing Hormone (LH) ovulation predictor kits
- Progesterone level on day 21 of the menstrual cycle
- Basal body temperature (BBT)
- Transvaginal ultrasound