Regular menstrual cycles each month are the result of regular ovulation. If a female is having irregular cycles, out of the range of every 21-35 days, or not having cycles at all, her ovulation is either irregular or not happening at all. In a normal cycle, at the start of each month, there is a group of eggs that are ready to be chosen from. In women who are ovulating regularly, one egg is chosen from that group and all of the others die off. If one is not chosen from that group because the patient is not ovulating, that group of eggs still dies off.
Ovulation induction is the process by which medications are given in order to help a women ovulate or to regulate her ovulation. This is done so that patients know when to time intercourse in an effort to conceive. In patients with irregular or no ovulation, depending on the cause of the irregularity, we can use lifestyle modifications, medications, either oral pills like clomiphene citrate or letrozole, or injections, called gonadotropins, to stimulate the development of a single follicle and subsequent ovulation of a single egg. We are not depleting a woman’s supply of eggs more rapidly, we are just growing one from that group that would have died off anyway.
Depending upon the particular patient, one of several treatments may be recommended. In women who do not ovulate, oral medications, rather than injection medications, are often recommended as the initial treatment. Some of the advantages of oral medications compared to injections include the ease of oral administration, fewer side effects, lower cost (of the medication itself, as well as the monitoring), lower risk of multiple pregnancies, and a reduced time commitment (related to monitoring during treatment). If the woman has tried oral medications or if oral medications are unlikely to be helpful, the next step is often to try ovulation induction with injection medications. Oral or injection medications may be used along with timed intercourse (TIC), intrauterine insemination (IUI), and/or in vitro fertilization.
When initiating treatment for ovulation induction, in most cases, one will have a baseline ultrasound to assess the ovaries at their “resting” state. If the ovaries look as they should, the patient will take the oral medication or give an injection once per day, for a number of days. The pill is taken by mouth and the injection can typically be given under the skin. After taking the medication for an allotted time period, the patient may be asked to have a pelvic ultrasound to measure follicle growth, and possibly a blood test to measure hormone levels. Depending upon the results of these tests, the dose of the medication may be increased or decreased. Blood testing and pelvic ultrasound may be repeated more times during a cycle. For women who do not ovulate on their own, the goal is to have one follicle that is at least 18 mm in size. If more than one follicle develops, depending on the number, the cycle may be cancelled due to a higher risk of becoming pregnant with twins, triplets, or more. In rare cases, the cycle may be converted to an in vitro fertilization cycle, so that the clinician can ultimately control the number of embryos that are transferred in the uterus.
The side effects of both oral and injection medications are usually minimal. With oral medications, there are side effects of hot flashes and night sweats as well as headaches to name a few. While these side effects are less likely with injection medications, patients can feel more emotional on all of the medications. Because the ovaries grow during treatment, a patient can have abdominal discomfort, and in more severe cases, nausea and vomiting. The most serious risks of oral and injection medication therapy are the development of ovarian hyperstimulation syndrome (OHSS) and conceiving a multiple pregnancy. OHSS is a condition in which the ovaries become enlarged and in severe cases, the woman may develop severe abdominal pain, vomiting, and blood clots. However, severe OHSS occurs in less than 2 percent of women undergoing treatment with injections and less than 1 percent of women undergoing treatment with oral medications.
The take home point is that if your menstrual cycles are irregular or you are not having a menstrual cycle at all, ovulation induction is the process that can help to regulate ovulation! Once ovulation is regulated, one can understand when to time either intercourse or an intrauterine insemination so they have a better chance of conceiving!
– Kari von Goeben, M.D.