Do intrauterine injection of human chorionic gonadotropin (hCG) before embryo transfer increases implantation and pregnancy rates in patients undergoing in vitro fertilization?

Abstract

To compare the value of the intrauterine injection of hcg in the implantation and ongoing pregnancy rates between two groups of patients undergoing in vitro fertilization. Prospective Study. Group A(n=38) received 500 IU of hCGvia intrauterine administration 7 minutes before embryo transfer andit was compared to a control group B(n=83) with no intrauterine hCG administration.Themain outcome measures were the implantation, the ongoing pregnancy rate, biochemical pregnancy, miscarriage, and twin pregnancy rates. The sample was further subdivided according to the stage of embryo transfer (blastocyst or cleavage). Both groups weresimilar for age, years of infertility, endometrial thickness, serum estradiol levels, number of MII oocytes obtained, fertilization rate and number of embryos transferred. We found no statistically differences in implantation(17.53 vs 17.67%; P=0.78) and ongoing pregnancy rates(26.31% vs 26.51%; P=0.29).The miscarriage rate(10% vs 9.09%, P=0.239) and twin pregnancy rates (40% vs 22.73%, P=0.4072) were also similar. There was a statistically significant difference in the biochemical pregnancy rate between the 2 groups (35.7% vs 9.37%, P=0.0442). When analyzing only blastocyst transfers(n=42), the implantation, miscarriage, ongoing,and biochemical pregnancy rates were similar. Nonetheless, the twin pregnancy rate was statistically significantly higher(66% vs 8.3%; P= 0.021) in Group A (13/38) as compared with Group B(29/84). The intrauterine administration of 500 UI of urinary hCG before the embryo transfer does not improve the implantation and pregnancy rates in patients undergoing in vitro fertilization treatment. We observed a statistically significant increase in twin pregnancy rates when using hCG before the transfer of blastocysts, nevertheless the sample should be increased before giving recommendations.