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Within one 24-hour period last week, I read two news articles on in vitro fertilization (IVF) that had completely opposite messages. One said that IVF success rates are upwards of 90% while the other said that less than 25% of women get pregnant after IVF. So what is the truth?

The Society for Assisted Technology (SART) is the principle professional organization for fertility specialists in the United States. Each year SART collects information from the nation’s fertility clinics, compiles them, and publishes them online. This allows patients and health care providers to both understand the fertility clinic success rates in their area and determine how that stacks up against the national average. For example, I was able to find out that in 2009, the most recent year available, there were more than 140,000 IVF cycles done in the US. Of those, 47% of cycles resulted in pregnancies for women under age 35 and 41% of cycles resulted in live births. So why does the media have such conflicting reports? Here is the fine print:

Age: The statistics I mentioned above were for women age 35 and younger. As in nature, older women are less likely to get pregnant from IVF and be able to carry a baby to term than younger women. For example, birth rates from IVF drop to 31% for 35-37 year olds, 22% for 38-40 year olds, 12% for 41-42 year olds, and 4% for women older than 42. Much of this age-related decrease is due to the fact that older women are less likely to respond to the hormones that cause the release of multiple eggs retrieved from a woman’s ovaries before IVF. This is good news for many oncofertility patients since younger women tend to respond better to hormones. One caveat for cancer survivors is that some cancers and their treatments may also affect the uterus and the ability to carry a child to term.

When comparing different fertility centers it is also important to note that the demographics of patients may vary between centers. In fact, the SART statistics include the following disclaimer,  “Caution: Patient characteristics vary among programs; therefore, these data should not be used for comparing clinics.” Besides age, differences in the overall health of the patients and diagnosis that causes infertility may affect success rates.

Number of Cycles: Another factor in IVF rates is number of cycles a woman undergoes and the SART database includes statistics on the success of each IVF cycle. Some women are able to participate in multiple cycles if the first one does not result in a baby. However, young cancer patients may not have time to undergo more than one egg retrieval cycle before starting fertility-damaging treatment. In addition, as the cost of IVF can be more than $10,000 and not all insurance covers treatment, multiple cycles can be financially prohibitive.

Multiple births: Between 15 and 30% of deliveries from assisted reproductive technologies result in multiple births, such as twins, compared with 1-2% in spontaneous pregnancies.  This is a result of implanting more than one embryo in a woman’s uterus after IVF. The industry standard is to transfer up to 2 embryos into a woman at a single time, although the American Society for Reproductive Medicine does authorize the transfer of more than 2 embryos for women over 38. Interestingly, implanting more embryos does not generally seem to increase the chance of pregnancy-just the chance of a multiple pregnancy. Since multiple pregnancies also increase the risk of complications it is important to examine the average number of embryos transferred at a clinic.

For all women, especially cancer survivors, it is important to keep in mind that a lot of factors go into the IVF success rates. Thus, many media reports can include information that is not completely accurate. Read additional mythbusters in oncofertility.

 

 

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Success rate in IVF

[...] Rates and Decreased IVF Success Rates, Says Advanced Fertility Center of Chicago ResearchMythbusters in Oncofertility: The Truth about IVF Success Rates Subscribe to RSS [...]

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