In women with polycystic ovaries, it has proved more effective to use frozen embryos than fresh embryos. A Chinese study then verified whether the same results were found in women with a regular cycle.
The researchers followed 2,157 women between the ages of 20 and 35 who were undergoing in vitro fertilization. All women had a regular cycle, so between 21 and 35 days. None of them had problems related to high blood pressure, diabetes, polycystic ovaries. In contrast, in the group there were women with fallopian tube problems or those suffering from unexplained infertility. In some cases, the cause of infertility was related to the male partner.
Each woman followed a cycle of gonadotropin-releasing hormone to stimulate ovulation. Following oocyte fertilization, doctors implanted fresh embryos in half of the participants. These also received extra progesterone treatment. The other half of the participants, however, received frozen embryos.
The rate of parts in the two groups was similar: 50.2% for the group of fresh embryos and 48.7% for that of the frozen embryos. However, in the first group there was a much higher rate of abortion in the second quarter (4.7%) than in the second group (1.5%). Furthermore, women who used frozen embryos had fewer problems with ovarian hyperstimulation syndrome.