Anovulation and ovulatory disorders account for approximately 20% of all cases of female infertility.
Ovaries are responsible for two major functions, production and release of oocytes (ovulation), and release of steroid hormones (estradiol, progesterone and androgens).
The term ovulatory disorders, denotes, a group of ovulatory disorders which lead to anovulation or defective ovulation.
Ovulatory disorders usually manifest as oligomenorrhea, hypomenorrhea or amenorrhea. Still, even women with a normal cycle (25-35days), may experience defective ovulation (15%).
Diagnosis of ovulatory disorders can be made by performing one of the following tests.
- PRG (progesterone)
This hormone is produced by the ovaries after ovulation has occurred and reaches its peak 7 days later. The test must be performed one week before the next period, meaning around the 21st day of a 28 day menstrual cycle, or the 28th day of a 35 day menstrual cycle. Progesterone levels predict ovulation quality. Normal values are considered between 16 ng/ml and 32 ng/ml.
- FSH (follicle-stimulating hormone) and E2 (estradiol)
When menstrual cycle disorders or inability of ovulation induction are present, day 3 of cycle measurement of FSH and E2 reflects ovarian function. Increased FSH levels are encountered in older women and reflect a decrease of follicular number and defective quality oocytes. If the level of FSH is over 25 mIU/ml, the chance of achieving pregnancy is less than 2%. Repeat testing is required because hormonal levels may fluctuate from cycle to cycle. If levels remain increased (>20 mIU/ml), menopause ensues.
- LH (luteinising hormone)
LH measurement, which normally increases 36 hours before ovulation, is an indirect method for ovulation prediction. The hormone can be measured in the blood or in urine (urine kits are available in pharmacies).
- Ultrasound Testing
During the follicular phase (first phase) of the cycle, by performing serial ultrasound scans, we can observe follicular size and progression. After ovulation, follicles disappear and free fluid in the pouch of douglas is observed.
Ultrasound testing can also detect genetic uterine anomalies, uterine fibroids, ovarian cysts, endometriosis and polycystic ovaries. Polycystic ovaries are characterised by increased ovarian size due to multiple small ovarian cysts, 2-8 mm in diameter. Polycystic ovarian syndrome is a common cause of anovulation and infertility in women.
Ultrasound testing allows also evaluation of the endometrium during the menstrual cycle. Thin endometrium (<7.5 mm) can cause infertility due to defective implantation. Very thick endometrium may be due to endometrial polyps or fibroids. In these cases, saline infusion sonography may give proper diagnosis.
- Endometrial Biopsy
Endometrial biopsy is performed to confirm ovulation and to determine whether the lining of the uterus (endometrium) is adequately developed to support pre-embryo implantation. Normal endometrial development depends upon secretion of the hormone progesterone by the corpus luteum (collapsed egg follicle) and the action of progesterone upon the uterine lining. If an abnormality is found, treatment with ovulation induction medication or progesterone suppositories may be administered.
Endometrial biopsy is easy, painless and can be done in the office. It is performed between the 21st and 25th day of the cycle.
Secretory endometrium is suggestive of ovulation. If there is a delay of endometrial development more than two days, luteal phase defect is the diagnosis . This regards 4% of women. LPD may cause infertility, or abortion.
In case of ovulatory disorders, hormonal therapy which aims at hormonal substitution or stimulation, gives very good results.