In a nutshell
This study compared the effects of frozen embryo transfers against fresh embryo transfers in women undergoing in vitro fertilization (IVF). The frozen embryo transfers significantly reduced the risk of ectopic pregnancy.
Some background
Couples who are trying to get pregnant often turn to assisted reproduction methods such as IVF (a fertility treatment where an egg is fertilized by sperm outside the body and then implanted into the woman’s uterus). IVF is a major risk factor for ectopic pregnancy. Ectopic pregnancy is a pregnancy that is implanted outside of the uterus. Usually ectopic pregnancies implant within the fallopian tubes (called a tubal pregnancy). Rates of ectopic pregnancies in IVF patients range from 2% to 5%.
Research has indicated that frozen-thawed embryo transfers result in fewer ectopic pregnancies compared to fresh embryo transfers, but there has been very little data to support this.
Methods & findings
This study included 31,925 women undergoing IVF from 2006 to 2013.
Fresh embryos were transferred in 15,042 patients. Of these, 6,431 (42.7%) had pregnancies. In the 12,255 patients where frozen-thawed embryos were transferred, 5,564 (45.4%) had pregnancies.
The percentage of ectopic pregnancies per pregnancy was 4.62% for the fresh embryo group and 2.22% for the frozen-thawed transfers. There were no significant differences in ectopic pregnancy rates based on the method of embryo freezing.
The bottom line
The study concluded that frozen-thawed embryo transfers were associated with a much lower risk of ectopic pregnancy compared with fresh embryo transfers. The authors noted that ovarian stimulation was also associated with an increased risk of ectopic pregnancy, and that any method of reducing the risk of ectopic pregnancy could be very important in assisted reproduction techniques.
What’s next?
Published By :
Fertility and Sterility
Date :
Sep 17, 2014
