In Vitro Fertilization (IVF)
Do Women With Endometriosis Have Lower IVF Success Rates?
One of the long unanswered questions from women experiencing endometriosis has been, “Do women with endometriosis have lower IVF success rates, particularly do they have lower rates of embryos implanting and lower live birth rates?”
Endometriosis and Embryo Implantation
The question of whether endometriosis lessens the chance of an embryo implanting has been discussed and studied over the last 25 years. Early studies that used day three embryos were mixed; some of these studies showed a lower chance of implantation in women with endometriosis, while others did not. Certainly, these older studies used embryos of very mixed quality. Recent studies using more uniform Day 5-6 embryos (blastocysts) have been more helpful as we can better determine the quality of embryos on Day 5. These studies have also shown mixed results.
Do Women With Endometriosis Have Lower IVF Success Rates?
A recent study in the February 2021 Journal of Fertility and Sterility used the most uniform embryos to study pregnancy rates; these were embryos that had Preimplantation Genetic Testing (PGT) and were determined to be chromosomally normal. These chromosomally normal embryos showed no decrease in implantation rates or ongoing pregnancy rates in women with endometriosis compared to other women who had undergone IVF with PGT
459 frozen embryo transfer cycles among 328 unique patients from the years 2016-2018 were studied; most of these cycles were in women who had male factor infertility, 54 cycles were in women with endometriosis, and 50 were in women of probable normal fertility who had to have their embryos tested for genetic purposes. The average age of these women was 35, with a normal average BMI.
The positive pregnancy rate in the patients with endometriosis was 80%, with a 61% live birth rate. These results were not statistically different from the other two groups and, in fact, trended to be slightly higher than the other two study groups, which showed live birth rates of 50% and 52%). It must be emphasized that all these transfers occurred during a frozen embryo transfer cycle.
How Does Endometriosis Cause Inflammation?
In women with endometriosis, there appears to be an increased inflammatory response in the pelvis with implantation of the lining of the uterus (the endometrium) on the ovaries, uterus, and surrounding tissues. Studies have shown that the endometrial tissue, which is not in the lining of the uterus, shows many abnormal properties compared to normal endometrium. There have been some studies that look at the lining of the uterus in women with endometriosis compared with women without endometriosis exhibit abnormal properties as well. Therefore, the question of whether the implantation of embryos may be lowered, too. This very well-designed study showed that the implantation rate in women with endometriosis was not any lower than other women when transferring frozen embryos.
Are Frozen Embryo Transfers More Successful for Endometriosis Patients?
This study should be very reassuring to all women with endometriosis as pregnancy rates, early pregnancy loss rates and live birth rates were no different than in women with male factor infertility and a group of women without proven infertility. Of note, all women were placed on oral contraceptive pills, which can suppress endometriosis for the month prior to the controlled frozen embryo transfer cycle. This raises the question of whether all women with endometriosis who undergo IVF should only have a frozen embryo transfer cycle rather than a fresh IVF cycle, and should all be treated with three weeks of oral contraceptive pills to suppress the endometrium prior to their transfer.
Endometriosis and Pregnancy Success
This is a very powerful study pointing to the fact that in women with endometriosis, their uterus is no less receptive to an embryo and having an ongoing pregnancy than in women with other infertility diagnoses.
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If you have more questions on endometriosis or you are experiencing difficulty getting pregnant, please contact us for an initial consultation. We are here to help.
