Overall, the success rates for IVF have improved markedly since 1978 (when Louise Brown was conceived), but success rates vary widely depending on the couple’s infertility factors and the clinic performing the IVF procedure (see Table 4). Success rates for U.S. IVF clinics are published on the CDC’s website (https://www.cdc.gov/art/index.html). The standardization of clinic success rates evolved from 1994 passage of the Fertility Clinic Success Rate and Certification Act (the so-called Wyden law), which seeks to protect U.S. consumers from inflated IVF success rates. Importantly, many subtleties influence clinic-specific IVF pregnancy rates, including patient selection bias (that is, some clinics tend to treat tougher cases, so their success rates might be lower than those of clinics that take only routine cases). The paucity of clinics that offer Natural Cycle IVF (NC-IVF) is likely related to this reporting requirement. NC-IVF can be an effective fertility treatment but the pregnancy rate will be less than for stimulated cycle IVF and the number of cancelled cycles will also be higher as patients may ovulate before egg collection, or fail to fertilize or fail to have a viable embryo to transfer.

Table 4 Factors Influencing IVF Success Rates

1. Patient’s age
2. Type of infertility diagnosis
3. Duration of infertility (Best prognosis if <5yrs)
4. Experience/expertise of the clinic
5. Number of embryos transferred
6. Type of IVF performed: Stimulated vs. Natural Cycle IVF

Unfortunately, at the present time all IVF cycles are reported the same way with the CDC failing to segregate results from NC-IVF from stimulated cycle IVF. Needless to say, this reporting method does not encourage clinics to offer NC-IVF as the apparent IVF success rate will be reduced by the inclusion of NC-IVF in the calculations.

For women younger than 34 years of age, most will achieve pregnancy within 1 to 3 treatment cycles; indeed, many succeed in their first attempt. For women older than 35 years, the success rates tend to decrease simply because the aging process affects the quality of these women’s eggs. For a detailed discussion of IVF success rates, couples should visit the website for the clinic where they are considering treatment. They should also discuss their specific likelihood of success with their reproductive endocrinologist. IVF pregnancy rates do vary by clinic, so patients should carefully scrutinize their chances for success at the particular clinic rendering treatment.

Carol comments:

This was one part of the process that I found to be a bit more predictable. In both my pregnancies, it took two IVF attempts to achieve a viable pregnancy. As tough as it was after each failed attempt, I tried to take something positive away. For example, after my very first IVF attempt resulted in a chemical pregnancy, I focused on the fact that I now knew an embryo could implant in the lining of my uterus.When I was trying to get pregnant the second time, I did a FET [frozen embryo transfer] with frozen embryos from the previous cycle. Again, it resulted in a chemical pregnancy. Based on that experience, we decided that we would not pursue another FET. I am convinced that maintaining a positive attitude during the process makes a big difference.