The Impact of Oocyte Maturity and Embryo Quality on Pregnancy Rate of In Vitro fertilization-EmbryoTransfer(IVF-ET) Program

Lee, Yu Il; Kim, Jae Hoon; Park, Hyun Jeong

Abstract

There are a number of factors affecting the pregnancy rate in in vitro fertilization(IVF): the etiology of infertility, ages of husband and wife, the type of ovarian stimulation,the number of aspirated oocytes, the maturity of oocyte, embryo quality, the number offertilized oocytes, the cumulative embryo score, and the number of embryos transferred. Amongthem the maturity of oocyte and the quality of embryo appear to be the most importantfactors influencing the pregnancy rate. The aim of this study designed to evaluate the effectof oocyte maturity, embryo quality, the number of embryos transferred, and the cumulativeembryo score to fertilization rate on whether the patient conceived or not. A total of146 consecutive cycles of in vitro fertilization-embryo transfer(IVF-ET) were studied usingtwo ovarian hyperstimulation protocols; follicular stimulating hormone(FSH)/ humanmenopausal gonadotropin(HMG)/human chorionic gonadotropin(hCG) and gonadotropin releasinghormone agonist(GnRH-a)/FSH/HMG/hCG.Following were the results.1. The quality and quantity of oocytes and embryos, fertilization rate, and cumulativeembryo score between two ovarian hyperstimulation protocols were not different.2. The more mature oocytes exhibited, the greater fertilization rates in both methods(p < 0.01).3. The average numbers of embryos transferred were 3.65 +/- 0.27 in conceived groupand 2.54 +/- 0.18 in nonconceived group, which was statistically higher in conceived group(p < 0.001).4. The pregnancy rate was higher if any matured embryo(Grade I) was present amongthe embryos transferred(p < 0.05).5. The average cumulative embryo score was 69.70 +/- 6.13 inconceived group and 43.51 +/- 3.41 in nonconceived group, which was statistically higher in conceived group(p < 0.001).These data suggest that the pregnancy rate is higher when the oocyte maturation isBetter, the number of embryos transferred is greater, there is at least one matured embryoamong the embryos transferred, and the cumulative embryo score is higher.