Goto Sakae, Shiotani Masahide, Kitagawa Masaru, Kadowaki Takashi, Noda Yoichi
Hanabusa Women's Clinic, Kobe, Hyogo, Japan.
Fertil Steril. 2005 Mar;83(3):721-3. doi: 10.1016/j.fertnstert.2004.07.974.
To evaluate the effectiveness, for patients who have only two embryos on day 2, of a two-step (consecutive) embryo transfer (ET) procedure in which a cleaved embryo is transferred on day 2 and a single blastocyst is transferred on day 5.
Observational comparative study.
Private IVF clinic.
PATIENT(S): Ninety two-step ET cycles were performed in patients who had two embryos on day 2 (two-step group). Ninety day-2 ET cycles were performed in age- and infertility-matched patients who had two embryos on day 2 (control group).
INTERVENTION(S): Cleaved-ET, extended culture of one embryo, and a second transfer of a blastocyst.
MAIN OUTCOME MEASURE(S): Implantation and pregnancy rates.
RESULT(S): The pregnancy and implantation rates in the two-step group (respectively 33.3% and 17.2%) were significantly higher than those in the control group (18.9% and 9.4%). Thirty-nine of the patients in the two-step group (43.3%) could not proceed to the second step of ET because no viable blastocyst could be obtained, but four of them conceived anyway.
CONCLUSION(S): Taking advantage of both day-2 ET and blastocyst transfer, two-step ET may be an effective option for ET in patients who have an insufficient number of embryos.
