What Is Ovulation Induction?
Ovulation induction involves stimulating the ovaries to develop a follicle or follicles. This technique can be used to induce ovulation of one egg in a woman who does not regularly ovulate, or it can be used to stimulate the development of multiple eggs in women who have had difficulty conceiving (superovulation).
Follicle stimulating hormone (FSH) is the signal your brain sends to the ovary to stimulate follicular growth. Ovulation induction therefore involves increasing the level of FSH in your body. This is typically done in one of two ways:
ORAL MEDICATION (E.G., CLOMIPHENE CITRATE, TAMOXIFEN, LETROZOLE)
These medications trick your brain into thinking you are not producing a follicle and, as a response, temporarily increase your own production of FSH.
INJECTABLE MEDICATION (GONADOTROPINS, E.G., FOLLISTIM®, GONAL-F®)
These medications are either purified or synthesized versions of FSH, so they directly increase your FSH levels. These medications do not rely on your own ability to produce FSH and so may be necessary in certain conditions when oral medications may not work.
Every patient responds differently to ovulation induction. A balance must be struck between increasing the number of eggs to improve the chance of pregnancy while not producing too many and putting you at significant risk for high order multiple pregnancies (triplets or more) or ovarian hyperstimulation. Under most circumstances, the patient is monitored closely with blood work and/or ultrasounds during ovulation induction to ensure the dose and response are appropriate. This way, if pregnancy does not occur after one cycle, adjustments can be made if necessary for the next cycle.
To achieve pregnancy, ovulation induction must be followed by some technique for getting the sperm and egg together. This is most commonly achieved through intrauterine insemination (IUI) or in vitro fertilization (IVF). In certain cases where infertility is due primarily to a lack of ovulation, however, the combination of ovulation induction with intercourse can significantly improve the chances of pregnancy.
What Is Intrauterine Insemination (IUI)?
With natural conception, sperm is deposited in the vagina and must swim through the cervix and uterus into the fallopian tubes. This is a very long journey and is even more difficult in cases of thickened cervical mucus or poor sperm motility (movement). Only a small percentage of sperm ejaculated in the vagina actually makes it into the tubes.
Intrauterine insemination involves placing washed sperm (either from a partner or donor) directly into the uterus at the time of ovulation, increasing the amount of sperm in the tubes and ultimately increasing the chance of pregnancy. This technique can be beneficial for patients with mild abnormalities of the sperm or couples with unexplained infertility, where no obvious cause for infertility has been found.
IUI can be timed to a woman’s natural ovulation or can be done after ovulation induction, with oral or injectable medications.
The basic steps in an ovulation induction/IUI cycle include:
- A baseline ultrasound is performed 3 days after your period starts.
- Ovulation induction medications (either oral or injectable) are started.
- Periodic ultrasounds are performed with or without blood work to measure follicular growth and follow the response to medication.
- Injection of HCG is given to trigger the final maturation and release of the egg(s) (ovulation)
- The IUI is performed 1–2 days later, timed to when the egg is being released.
- A progesterone blood test is performed several days after the IUI to confirm ovulation.
- A pregnancy test is performed 2 weeks after the IUI.
For IUI to be successful, at least one fallopian tube must be open so the sperm and egg can come together and fertilization can occur. If both tubes are blocked, in vitro fertilization is recommended as fertilization occurs outside the body and thus does not require open tubes.