Single blastocyst transfer: a prospective randomized trial.

OBJECTIVE

To determine the efficacy of single blastocyst transfer.

DESIGN

Prospective randomized trial.

SETTING

Private assisted reproductive technology unit.

PATIENT(S): Forty-eight women undergoing IVF-embryo transfer with day 3 FSH <or=10 mIU/mL and at least 10 follicles >12 mm in diameter on day of hCG administration.

INTERVENTION(S): Embryo culture to the blastocyst stage in sequential media G1/G2 followed by transfer of either one or two blastocysts.

MAIN OUTCOME MEASURE(S): Implantation rate, ongoing pregnancy rate, and twinning.

RESULT(S): The transfer of a single blastocyst resulted in an implantation and ongoing pregnancy rate of 60.9% with no twins. The transfer of two blastocysts resulted in an implantation rate of 56%, an ongoing pregnancy rate of 76% with a 47.4% incidence of twins.

CONCLUSION(S): Single blastocyst transfer is an effective method of eliminating multiple births while maintaining high pregnancy rates in this selected group of patients.