Ovulation induction: how does it work?

In women who have difficulty ovulating or who are undergoing assisted reproduction treatment, ovulation induction is used.

Ovulation induction is a pharmacological treatment that is part of the medium assisted procreation procedures.

Ovulation induction is recommended for:

• induce ovulation in women who cannot ovulate on their own such as women with polycystic ovary syndrome , who have very irregular cycles
• increase the number of egg cells that reach maturity in a single cycle, to increase the chances of conception (particularly in IVF treatments)
• in cases of unexplained infertility where medications may cause 2-3 eggs to mature, as opposed to just one. This treatment improves the quality and quantity of ovulation, increasing pregnancy rates.

What drugs are used to induce ovulation?

The main drugs used are:

• Clomiphene citrate (Seraphene and Clomid): This is an oral drug that induces ovulation by blocking estrogen receptors. This artificial anti-estrogen effect makes the body believe that estrogen levels are low. This in turn stimulates the production of more follicle stimulating hormone (FSH). Clomiphene citrate should be taken under monitoring (which can be ultrasound or done with dosing blood estrogen levels and dosing LH levels in urine)
• Follicle-stimulating gonadotropins : stimulate the ovaries to produce follicles in women who do not ovulate spontaneously, who have very irregular cycles or are used to increase the number of eggs produced in women who ovulate regularly. They are also used in IUI and IVF treatments. Follicular monitoring is important to avoid complications. Follicle-stimulating gonadotropins are divided into menopausal (ie obtained from hormones extracted from the urine of women in menopause) or recombinant. The menopausal gonadotropins are commercially available in injectable form under the names: Fostimon, Humegon, Menogon and Metrodin.
  Recombinant gonadotropins are obtained artificially and are marketed in injectable form under the names: Gonal-f and Puregon both based on recombinant FSH and Luveris based on recombinant LH.
• Human chorionic gonadotropins  (or HCG): they are used to induce ovulation by mimicking the action of LH which induces the bursting of the follicle and therefore ovulation. They also stimulate the corpus luteum to secrete progesterone to prepare the lining of the uterus for implantation of the fertilized egg. Ovulation is usually 30-36 hours after the injection of human chorionic gonadotropins. However, it is advisable to have intercourse even on the evening of the injection. Human chorionic gonadotropins are marketed in injectable form under the names: Gonasi, Ovitrelle /Ovidrel, Pregnyl or Profasi.

After ovulation progesterone may be prescribed to support the luteal phase.

In some cases, the doctor prefers to prescribe chorionic gonadotropins instead of progesterone (especially in the case of in vitro fertilization).

In this case, false positive pregnancy tests are obtained if the tests are carried out close to the end of the therapy.