Although fresh embryos are typically preferable for couples going through in vitro fertilization, a new study suggests that women who have been diagnosed with polycystic ovary syndrome (PCOS) are likely to have a “safer and more successful” pregnancy if they use frozen embryos.
The joint study from Penn State College of Medicine and Chinese researchers, published in the New England Journal of Medicine, found that using frozen embryos can help improve the rate of live births and lower the rate of complications such as high blood pressure, preterm delivery, low birth weight, birth defects and pregnancy loss in women with PCOS.
According to the Mayo Clinic, PCOS is a common endocrine system disorder that causes enlarged ovaries. Women with PCOS may have infrequent or prolonged periods, acne, excess hair growth or obesity issues, including type 2 diabetes and heart disease. The cause of PCOS is not known but it can contribute to infertility and needs to be treated by a doctor because you may need medication to help you ovulate if you're trying to become pregnant.
Women in the Penn State study were randomly chosen to receive either fresh embryos or frozen embryos for their first cycle of IVF. Interestingly, the women who received frozen embryos were nearly 86 percent less likely to have ovarian hyperstimulation syndrome (where ovaries become swollen and painful due to having too many injectable hormones in your system), a higher rate of live births and higher birth weights.
However, researchers say there were two negative outcomes associated with the use of frozen embryos for IVF. Women who received frozen embryos were more likely to have preeclampsia and had a slightly higher incidence of neonatal death. While the neonatal death rate was not statistically significant, researchers say both outcomes need to be studied further.
In any case, experts say that if a couple needing IVF has less embryos available for implantation, "freezing them may give a woman a better chance of becoming pregnant."