Ovulation

The Ovulation Process

Every month a normally ovulating female releases a mature egg according to precise timing governed by hormones.

The hypothalamus is a small gland located at the base of the brain, which can be thought of as a “thermostat.” Estrogen levels are monitored by the hypothalamus and as they increase, the hypothalamus signals the pituitary to reduce production of FSH. Once the hormone levels indicate that the follicles are mature, the hypothalamus signals the pituitary to release a surge of luteinizing hormone (LH). The spike in LH levels triggers ovulation approximately 36 hours after the surge. The ovaries begin to produce progesterone, which also supports the development of the endometrium. Rising levels of human chorionic gonadotropin (hCG), produced by the placenta, are an indication of pregnancy. If pregnancy does not occur, the lining of the endometrium breaks down and is released during menstruation.

Lack of ovulation is termed “anovulation” and irregular ovulation is termed “oligoovulation”.

Causes of Ovulatory Disorders

Ovarian Failure

Women are born with all the eggs they will have for a lifetime and one is usually ovulated during each monthly menstrual cycle. As women age, infertility increases as ovarian function begins to decline until menopause, where no more eggs are released and FSH levels are very high. Ovarian failure, or diminished ovarian reserve, means that the ovaries cannot produce the quality and quantity of eggs that will normally fertilize and develop. Day 3 FSH levels are elevated in these patients and response to the clomiphene citrate challenge test is abnormal.

Diminished ovarian reserve may occur early in some women, and the main causes include: cigarette smoking, genetic abnormalities (certain X chromosome abnormalities), aggressive medical treatments (radiation for cancer), and ovarian surgery, such as for endometriosis. These women are often candidates for HRC’s donor egg program.

Polycystic Ovarian Syndrome (PCOS)

PCOS is a common condition characterized by elevated androgens (male hormone), reduced insulin sensitivity, and numerous cysts on the ovary. Elevated androgens can lead to infrequent or irregular ovulation.

Thyroid Dysfunction

Abnormally high (hyperthyroidism) or low (hypothyroidism) levels of thyroid hormone can cause irregular ovulation thought to be due to the high levels of estrogen associated with these conditions.

Hyperprolactinemia

Prolactin is responsible for breast milk production in pregnant women. Elevated levels of the hormone prolactin can lead to ovulatory disorders and infertility. Elevated levels in the absence of pregnancy cause irregular ovulation by reducing the levels of FSH and LH.

Adrenal Dysfunction

Androgens are produced by the adrenal glands and abnormally elevated levels lead to oligoovulation. Increased androgens are associated with elevated levels of prolactin, and/or tumors on the ovary, pituitary, or adrenal gland.

Other Causes of Ovulatory Disorders

Excessive exercise, stress, and anorexia can also lead to irregular ovulation. Sometimes eggs will not fertilize and develop into health embryos for unexplained reasons. In many cases, these couples achieve pregnancy with donor egg in vitro fertilization (IVF).

Signs of Ovulation

Some women ovulate on the same day of their menstrual cycle every month. Other women may ovulate on different days each month. It helps to pay attention to the signs that will indicate you are ovulating. The average menstrual cycle is usually between 28 and 32 days; therefore women with a 28-day menstrual cycle usually ovulate between days 13 to 15 — about two weeks after the start of the menstrual period.

Common ovulation signs in most women include:

• Change in cervical mucus (fluid). One of the roles cervical mucus plays is to help the sperm travel up through the uterus and into the fallopian tubes. When your cervical fluid has a creamier consistency, resembling egg whites, it is a sign that you are near ovulation or are ovulating.
• Change in basal body temperature (BBT). Typically, your temperature remains consistent prior to ovulation. As you get closer to ovulation, you may notice a slight decline, and then there will be a sharp increase right after ovulation. The increase is an indication that ovulation has just occurred. By tracking your BBT accurately over a few months, you may be able to predict when ovulation occurs.
• Change in cervical position or firmness. You can study your body to figure out what your cervix normally feels like and how it changes during ovulation. During ovulation, your cervix is soft, high, open and wet.

There are secondary signs of ovulation, which may not be as consistent. They include: light spotting, slight cramping/pain on one side of the pelvis, increased sex drive, tender breasts, bloating in the abdomen and a heightened sense of taste, smell or vision.

Ovulation predictor kits (OPKs) are tests that detect the level of luteinizing hormone (LH) in your urine. LH typically rises prior to ovulation. Using an OPK during a range of possible ovulation times during the month allows a woman to pinpoint the LH surge so she knows before ovulation occurs and can have sexual intercourse prior to ovulation, which is considered the best time.

Clomid Ovulatory Disorders

Ovulation disorders are a common cause of infertility and are present in up to 30 percent of cases. Your fertility specialist at HRC will order numerous tests to assess ovulation. These may include FSH, LH, estrogen, progesterone, androgens, thyroid and adrenal tests. Other infertility tests might include an ultrasound exam to visualize the ovaries and a clomiphene citrate (Clomid) Challenge Test.

Treating Ovulatory Disorders

Irregular ovulation can usually be treated effectively with medications such as Clomid, Metformin, Bromocriptine, or FSH unless it is due to reduced ovarian reserve or ovarian failure.

The best option for patients with ovarian failure is IVF using donor eggs.

To schedule a consultation with one of our Reproductive Specialists, call us at 866-HRC-4IVF or click the button below: