WHAT IS OVULATION INDUCTION ALL ABOUT AT DENVER FERTILITY CLINICS?

There are various causes of anovulation; one of the most common is polycystic ovarian syndrome (PCOS). Women who have PCOS or have irregular menstrual cycles are the primary candidates for ovulation induction.   Ovulation induction can also be used in women who have regular cycles and ovulate regularly.

At Rocky Mountain Fertility Center, The most common medications used to help with the  growth of follicles are listed below. Treatment with these medications can result in a successful pregnancy if the patient’s remaining eggs are viable and there are no other causes of infertility. The medications are:

• Clomiphene is an oral tablet that is taken between days 3-7 or 5-9 of the menstrual cycle. It works by inducing the pituitary gland to release hormones that stimulate ovulation. Clomiphene is successful in more than 80% of cases, but carries certain risks.
• Injectable gonadotropins contain follicle stimulating hormone (FSH). This hormone induces the development of one or more follicles in women who do not ovulate naturally. The injections are begun early in the menstrual cycle and continued daily for up to two weeks until an ultrasound examination confirms the development of a mature follicle.

• Letrozole is an oral medication that works in a similar fashion to Clomiphene.  It is not FDA approved for ovulation induction but is used by most fertility specialists. Letrozole is cleared from the body very quickly, and is less likely than Clomiphene to affect the endometrium or cervical mucus.

Once ultrasound examination of the ovaries confirms the development of a mature follicle, an injection of HCG is administered. This will induce ovulation in approximately 36-42 hours.

About 90% of women who do not ovulate naturally can successfully induce ovulation with one of these therapies. Ovulation induction is typically tried for up to about three to six months, and if it does not result in pregnancy, in vitro fertilization is usually considered as the next step.

The major risk associated with ovulation induction medications is ovarian hyperstimulation syndrome (OHSS), which can occur in about 1% of cycles. OHSS can result in enlarged ovaries, abdominal pain, and buildup of fluid in the abdomen. In extreme cases, OHSS may require hospitalization.

The risk of OHSS is lower with Letrozole and Clomiphene than it is with the HMG medication, and when Injectable gonadotropins are carefully monitored, OHSS can almost always be avoided. Multiple pregnancies are also possible when ovulation induction; approximately 25% of cases result in multiple pregnancies as a result of this therapy.