Thursday 16 December 2010
Clinical research by Chicago-area infertility specialist Richard Sherbahn, MD, reveals increased embryo quality and higher live birth rates with in vitro fertilization when the follicular fluid is in an ideal temperature range.
Maintaining the temperature of follicular fluid in an ideal range during the in vitro fertilization (IVF) egg retrieval procedure can improve IVF live birth success rates, according to a clinical study conducted by the Advanced Fertility Center of Chicago (AFCC).
“During IVF, we retrieve eggs from a woman’s ovaries,” explains Dr. Sherbahn, a board-certified reproductive endocrinologist and infertility specialist. “The eggs are retrieved from ovarian follicles and we obtain the eggs and follicular fluid in which they develop.
“When the eggs are removed from the ovary, the fluid and the eggs experience a temperature change because the woman’s body temperature is warmer than the room temperature,” he says, “We found that if this temperature change is excessive, IVF live birth rates are significantly decreased.
“In our study, we performed 1,659 egg retrieval procedures in women under age 43,” Dr. Sherbahn explains. “The extracted fluid and eggs went into our laboratory and we checked the fluid temperature. Our objective was to see if the follicular fluid temperature made a difference in an embryo’s ability to develop into a good-quality blastocyst—and its effect on the IVF live birth success rate.”
A blastocyst is an embryo that has developed for five to six days after fertilization and has developed two distinct cell types and a central cavity filled with fluid. In vitro fertilization done with transfer of blastocyst-stage embryos has been shown to have a higher rate of success than transferring earlier-stage embryos.
“Our research found that maintaining follicular fluid temperatures in a narrow range resulted in improved outcomes: higher rates of blastocyst development, higher rates of embryo implantation in the uterus and more live births,” Dr. Sherbahn reports.
The cases were divided into three groups for analysis: the ideal-temperature group had a live birth rate of 52.8% per egg retrieval. The low-temperature group and high-temperature group had live birth rates of 44.1%, and 37.7% respectively.
“Our research indicates that the more the ideal temperature is maintained, the better the resulting embryo quality and the higher the live birth success rates,” Dr. Sherbahn concludes.
“We use heated blocks for the test tubes containing the fluid and the eggs rather than letting them sit in an open environment with no temperature control,” he explains. “We constantly monitor the blocks and the fluids to maintain the ideal temperature for the eggs.
“The standard temperature for culturing human embryos is 37.0 degrees Centigrade (98.6 degrees Fahrenheit)—but carefully controlled studies have not been published to prove this truly is the ideal temperature. Likewise, there has not been anything published clarifying the ideal temperature for eggs during the egg retrieval. Our study is a start; further research is needed in this area,” explains Dr. Sherbahn.