Endometrial infusion of human chorionic gonadotropin at the time of blastocyst embryo transfer does not impact clinical outcomes A randomized double blind placebo controlled trial

This randomized double-blinded placebo-controlled trial of 300 patients undergoing fresh or frozen embryo transfer (ET) demonstrates that endometrial human chorionic gonadotropin infusion at the time of blastocyst ET does not improve sustained implantation rate.

Kathleen H. Hong, M.D., Eric J. Forman, M.D., Marie D. Werner, M.D., Kathleen M. Upham, B.S., Christina L. Gumeny, B.S., Ayesha D. Winslow, M.S., Thomas J. Kim, M.D. Richard T. Scott, Jr., M.D., H.C.L.D.

Volume 102, Issue 6, Pages 1591-1595


To determine whether endometrial hCG infusion at the time of human blastocyst transfer impacts implantation rates.

Randomized double-blinded placebo-controlled trial.


Infertile couples with the female partner less than 43 years old (n = 300) undergoing fresh or frozen ET of one or two blastocysts.

Patients undergoing ET were randomized into either a treatment or a control group. The treatment group received an infusion of 500 IU of hCG diluted in ET media. The control group received a sham infusion of ET media. Infusions were done using a separate catheter less than 3 minutes before actual ET.

Main Outcome Measure(s):
Sustained implantation rate: ongoing viable gestation (primary outcome) and ongoing pregnancy rate (secondary outcome).

A total of 473 blastocysts were transferred into 300 patients. There were no differences between the two groups in sustained implantation rate (48.1% in the hCG group, 44.2% in the control group) or ongoing pregnancy rate (58.8% in the hCG group, 52.0% in the control group).

Endometrial infusion of hCG at the time of blastocyst ET does not improve sustained implantation rates.

Clinical Trial Registration Number:

  • Shvetha Zarek

    Dr. Hong and colleagues performed a double blind, placebo- controlled trial of 300 infertile couples randomized to either endometrial infusion of 20 µl of embryo transfer culture media with 20, 000 IU of purified urinary placental hCG or 20 µl of ET media without hCG. Infusion was administered 3 minutes before embryo transfer. Couples could undergo fresh or frozen embryo transfer, with or without CCS with either single or double embryo transfer. They report that there were no significant differences in their primary outcome, sustained implantation rate (defined as a transferred embryo that reached a viable gestational age >24 weeks) in the intervention and control group. (48.1% v 44.2%. p=.39). In addition, the authors performed a planned interim safety analysis and with a futility analysis halfway through the study and determined that it was unlikely that a demonstrable difference in the primary outcome would be detected between the two groups in the remainder of the study.

    Congratulations to the authors for presenting an excellent, well designed study on the utility of endometrial hCG treatment before embryo transfer. It was interesting to note that although, overall, there were no significant differences in the primary and secondary outcomes, the hcg arm consistently demonstrated higher sustained implantation rate per embryo and/or ongoing pregnancy rate per transfe by treatment arm and by sub-group analyses including embryo transfer order, fresh versus cryopreserved embryo transfers, and by embryo transfers with CCS screened euploid embryos. Thank you very much for a thought provoking study.

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