Small study finds phytoestrogens boost IVF-ET success
Verfasst: 02 Jan 2005 11:26
Small study finds phytoestrogens boost IVF-ET success
Last Updated: 2004-12-31
NEW YORK (Reuters Health) - High dosages of phytoestrogens can improve pregnancy rates in women undergoing in vitro fertilization and embryo transfer (IVF-ET), Italian researchers report.
Women who took 1,500 mg of soy isoflavones per day along with progesterone injections for luteal phase support had significantly greater rates of implantation, clinical pregnancy, ongoing pregnancy and delivery than women given progesterone injections with placebo, Dr. Vittorio Unfer of the Obstetrics and Gynecology Center in Rome and colleagues report in the December issue of Fertility and Sterility.
Progesterone injections for luteal phase support after oocyte retrieval are standard practice, Dr. Unfer and his team write, but the role of estrogen supplementation has been controversial. However, ovarian estrogen production does play a role in endometrial development in cycles in which patients undergo a downregulation protocol with GnRH-a, they note. They conducted the current study to determine if high doses of phytoestrogens -- shown by the researchers in previous research to have estrogenic effects on the endometrium of postmenopausal women -- could help support implantation.
The researchers randomized 213 patients to receive phytogestrogen supplementation or placebo each day after oocyte retrieval. Women continued to take the supplement until a pregnancy was sonographically confirmed, or until a negative serum pregnancy test. Women in the phytoestrogen group completed a total of 155 cycles, while women on placebo completed 129 cycles.
The phytoestrogen tablets contained 40%-45% genestein, 40%-45% diadzein and 10%-20% glycitein by weight.
Among women given the supplements, 25.4% of the embryos transferred achieved implantation, compared to 20.2% among women given placebo. Clinical pregnancy was seen in 39.3% of women on phytoestrogens and 20.9% of those on placebo. The rate of successful delivery per clinical pregnancy was 30.3% among women who took phytoestrogens vs. 16.2% for women on placebo.
The phytoestrogens could work by producing estrogenic effects on the endometrium, the researchers note, or they might exert an anti-estrogenic, modulating effect in the presence of high levels of circulating endogenous estrogen.
Larger studies to evaluate efficacy and safety are necessary before phytoestrogens can be routinely recommended for IVF-ET, the researchers write. "Nevertheless, our findings suggest new avenues for future fertility research and treatment with phytoestrogens and strengthen the importance of investigating the features of estrogenic action on endometrium before implantation," they conclude.
Source : Fertil Steril 2004;82:1509-1513.
Last Updated: 2004-12-31
NEW YORK (Reuters Health) - High dosages of phytoestrogens can improve pregnancy rates in women undergoing in vitro fertilization and embryo transfer (IVF-ET), Italian researchers report.
Women who took 1,500 mg of soy isoflavones per day along with progesterone injections for luteal phase support had significantly greater rates of implantation, clinical pregnancy, ongoing pregnancy and delivery than women given progesterone injections with placebo, Dr. Vittorio Unfer of the Obstetrics and Gynecology Center in Rome and colleagues report in the December issue of Fertility and Sterility.
Progesterone injections for luteal phase support after oocyte retrieval are standard practice, Dr. Unfer and his team write, but the role of estrogen supplementation has been controversial. However, ovarian estrogen production does play a role in endometrial development in cycles in which patients undergo a downregulation protocol with GnRH-a, they note. They conducted the current study to determine if high doses of phytoestrogens -- shown by the researchers in previous research to have estrogenic effects on the endometrium of postmenopausal women -- could help support implantation.
The researchers randomized 213 patients to receive phytogestrogen supplementation or placebo each day after oocyte retrieval. Women continued to take the supplement until a pregnancy was sonographically confirmed, or until a negative serum pregnancy test. Women in the phytoestrogen group completed a total of 155 cycles, while women on placebo completed 129 cycles.
The phytoestrogen tablets contained 40%-45% genestein, 40%-45% diadzein and 10%-20% glycitein by weight.
Among women given the supplements, 25.4% of the embryos transferred achieved implantation, compared to 20.2% among women given placebo. Clinical pregnancy was seen in 39.3% of women on phytoestrogens and 20.9% of those on placebo. The rate of successful delivery per clinical pregnancy was 30.3% among women who took phytoestrogens vs. 16.2% for women on placebo.
The phytoestrogens could work by producing estrogenic effects on the endometrium, the researchers note, or they might exert an anti-estrogenic, modulating effect in the presence of high levels of circulating endogenous estrogen.
Larger studies to evaluate efficacy and safety are necessary before phytoestrogens can be routinely recommended for IVF-ET, the researchers write. "Nevertheless, our findings suggest new avenues for future fertility research and treatment with phytoestrogens and strengthen the importance of investigating the features of estrogenic action on endometrium before implantation," they conclude.
Source : Fertil Steril 2004;82:1509-1513.