Minimal Stimulation IVF-ET

The first IVF-ET baby, Louise Brown, was born in 1978 and was conceived without the benefit of any fertility drugs. In the years that followed her birth, the experience of most clinics was that the success of IVF-ET was improved by administering injectable fertility drugs to the woman. Thus, the use of injectable fertility drugs became the routine in IVF-ET. One disadvantage of injectable drugs is that they substantially increase the cost of IVF-ET. Not only are the injectable drugs themselves expensive; but their use necessitates more office visits and testing in the days preceding oocyte retrieval and more work for the IVF-ET laboratory personnel after retrieval to care for the resultant increased number of oocytes. In order to give some chance of pregnancy to infertile couples who simply cannot afford conventional IVF-ET with injectable drugs, some clinics have continued to offer IVF-ET without injectable drugs, which significantly decreases the total costs of the procedure, as well as the success rate.

There are several slightly different ways in which IVF-ET can be performed without the use of injectable gonadotropins. One is "minimal stimulation IVF-ET" in which the woman takes the relatively inexpensive oral fertility drug clomiphene citrate (Serophene® or Clomid®) early in her cycle. The other way is to take no fertility stimulants whatsoever, and simply aim to retrieve the oocyte produced in the woman's natural cycle. The maximum "take home baby" rate (chance of having an actual living child) of minimal stimulation IVF-ET is generally believed to be about 10%. In the U.S.A. in 1998, the most recent year for which figures are available, the "take home baby" rate of natural cycle IVF-ET in women less than 40 years old was 8.5% per cycle started, and 13% per oocyte retrieval procedure. The particularly low success rate of natural cycle IVF-ET may reflect a selection bias. That is, physicians may recommend natural cycle IVF-ET to patients who have previously demonstrated poor responsiveness to fertility drugs (thinking the fertility drugs will be of no benefit to them), thereby effectively selecting patients for natural cycle (IVF-ET) who have a particularly poor chance of becoming pregnant. Even if this is the case, it is unreasonable to expect any more than a 10-15% take home baby rate from minimal stimulation IVF-ET with current technology and methods.

The patient evaluation before minimal stimulation IVF-ET is the same as for conventional IVF (see pages 9-10). The patient undergoing minimal stimulation IVF-ET will take birth control pills in the cycle before stimulation. We will perform a baseline ultrasound around the time of your expected period after the pills. If that ultrasound is normal, the patient will take clomiphene (50 mg), two tablets by mouth daily, cycle days three through seven. The next ultrasound will be performed on cycle day eight. Several more ultrasounds will be performed in subsequent days, the exact number and frequency depending on the rate of growth of the oocyte-containing structures (follicles). Usually, no blood work is needed for monitoring for couples undergoing minimal stimulation IVF-ET. On the date that the ultrasound indicates that the largest follicle has an average diameter of 18-20 mm, human chorionic gonadotropin (hCG) 10,000 units intramuscularly or subcutaneously will be injected in the evening. Oocyte retrieval will be performed 35 hours after the hCG injection. A GnRH antagonist and/or gonadotropins may be administered late in the cycle to suppress an unwanted spontaneous LH surge

The basic techniques of oocyte retrieval, insemination, embryo culture, embryo transfer, progesterone supplementation after embryo transfer, and pregnancy testing after embryo transfer are very similar or identical to those used in conventional IVF-ET and are discussed elsewhere. Because patients undergoing minimal stimulation or natural cycle IVF-ET have only very few or one follicle(s), it may be possible to perform the oocyte retrieval procedure without the services of the anesthesiologist. Your physician can provide some medications for pain relief during the procedure, and most patients do well with this approach. You should discuss this matter with your physician before making a final decision.

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