Clinical outcomes of two different endometrial preparation methods for cryopreserved-thawed embryo transfer in patients with a normal menstrual cycle.

Aim: To compare the clinical outcomes of cryopreserved-thawed embryo transfer among patients with a normal menstrual cycle who had natural or hormone-replacement cycles. Methods: From January 2004 to June 2006, cryopreserved embryos following conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) were thawed and transferred in a total of 720 natural cycles and 136 hormone-replacement cycles. Results: Cryopreserved-thawed embryo transfer in patients who had a natural or hormone-replacement cycle resulted in clinical pregnancy in 43.1% and 40.4%, respectively; a rate of miscarriage of 14.5% and 23.6%, respectively; and a rate of ongoing pregnancy and delivery of 36.5% and 30.9%, respectively. None of these differences were statistically significant. Conclusions: Patients with a normal menstrual cycle who have natural or hormone-replacement cycles can be expected to have comparable clinical outcomes with cryopreserved-thawed embryo transfer. (Reprod Med Biol 2007; 6: 53-57).

Five cases of dizygotic triplet pregnancy following assisted reproductive techniques.

Of 816 patients who became clinically pregnant by assisted reproductive techniques between September 2000 and August 2004, we experienced 10 cases (1.2%) of monozygotic twinning, and in five of these 10 cases, implantation of another embryo resulted in dizygotic triplets. Here, we report these five cases of dizygotic triplets. Fresh embryo transfer was performed in all five cases. Intracytoplasmic sperm injection or assisted hatching was not carried out in these cases. Blastocyst transfer was performed in three cases. Three embryos were transferred in case 1 (40-year-old female). While only two embryos were transferred in the other four cases so as to avoid triplet pregnancy, triplet pregnancies were confirmed. Triplet pregnancy was maintained in three cases, but in the other two cases, monochorionic twinning resulted in miscarriage during the first trimester. For the three patients who delivered the triplets, while the postnatal growth has been normal for all nine babies, the mothers were hospitalized for a long period of time, and an emergency cesarean section was performed on two patients. Because triplet pregnancy could not be completely prevented even when only two embryos were transferred, physicians should be sure to obtain informed consent in similar cases. (Reprod Med Biol 2005; 4: 59-64).

Elective single embryo transfer: Comparison of blastocyst and cleavage-stage embryo transfer.

Objective: Blastocysts are reportedly suitable for preventing multiple pregnancies as a result of the high implantation rate per embryo. The present study compared clinical results for elective single embryo transfer (ET) between blastocysts and cleavage-stage embryos in order to ascertain the usefulness of blastocyst culturing in single ET. Methods: Between January 2002 and December 2004, conventional in vitro fertilization ET and/or intracytoplasmic sperm injection was carried out for single ET in 86 cycles, to prevent multiple pregnancies (for medical reasons or because of patient wishes). Results: Among the 80 cycles in which a fresh embryo was transferred, pregnancy/implantation rates per ET were 35.3% for day 2/3 ET and 50.0% for day 5 ET, and pregnancy/implantation rates per oocyte retrieval were 35.3% for day 2/3 ET and 44.2% for day 5 ET. Ongoing pregnancy/delivery rates per oocyte retrieval were 32.4% for day 2/3 ET and 38.5% for day 5 ET. Monozygotic twinning occurred in one case of day 5 ET. Conclusions: Pregnancy rates per single ET tended to be higher for day 5 ET than for day 2/3 ET. However, no marked differences were identified in ongoing pregnancy/delivery rates per oocyte retrieval between groups. (Reprod Med Biol 2005; 4: 197-201).