Clinical outcomes of transfer of frozen and thawed single blastocysts derived from nonpronuclear and monopronuclear zygotes.

PURPOSE: In assisted reproductive technology, normal zygotes are bipronuclear (2PN) during fertilization confirmation; however, sometimes, nonpronuclear zygotes (0PN) and monopronuclear zygotes (1PN) are found during routine observations. METHODS: To elucidate the clinical usefulness of in vitro-fertilized embryos, we investigated the rates of clinical pregnancy, live birth, miscarriage, and congenital abnormality after transfer of frozen-thawed 1PN- and 0PN-derived single blastocysts at Denentoshi Ladies Clinic, Kanagawa, Japan. RESULTS: The rates of pregnancy and live birth for 1PN-derived blastocysts obtained by conventional in vitro fertilization were 37.5% and 27.1%, respectively, which was not significantly different from those for 2PN-derived blastocysts; however, the rates for 0PN-derived blastocysts were significantly lower. The pregnancy and live birth rates for 0PN-derived embryos obtained by intracytoplasmic sperm injection (ICSI) were 45.7% and 34.8%, respectively, which was not significantly different from those for 2PN-derived blastocysts; however, the rates for 1PN-derived blastocysts were significantly lower (4.0% for both) than those for 2PN- and 0PN-derived blastocysts. No congenital abnormalities were found in infants resulting from transfer of 0PN- or 1PN-derived blastocysts. CONCLUSIONS: Both 1PN- and 0PN-derived blastocysts can be used for embryo transfer; however, care should be taken in making decisions about 1PN-derived blastocysts, especially if they are obtained by ICSI.

Aging increases oxidative stress in semen.

PURPOSE: As age increases, oxidative stress increases, sperm motility decreases, and DNA fragmentation increases. To date, reports of age-related effects on semen have focused on reactive oxygen species (ROS) or total antioxidant capacity (TAC) as indicators of oxidative stress. However, assessments of ROS and TAC must be considered within a more comprehensive context in order to correctly evaluate oxidative stress and interpret findings. In this regard, the purpose of this study was to investigate the relationship between the static oxidation reduction potential (sORP) and paternal age with the goal of using the sORP as an indicator of semen oxidative stress. MATERIALS AND METHODS: Semen samples from 173 men were analyzed for the following parameters: volume, motility, and beat cross frequency (BCF). The sORP was measured by using the MiOXSYS™ system. The correlation between semen parameters and the sORP level was analyzed as a function of age. The rate of sORP positivity was compared between men <34 and ≥34 years of age, with a positive sORP defined as a level ≥1.38. RESULTS: Volume, motility, and BCF were negatively correlated with age (p<0.001). The semen sORP level was positively correlated with age (p<0.05). The rate of sORP positivity was significantly increased in men ≥34 years of age compared with that in men <34 years of age (33% compared with 12%, respectively; p<0.01). CONCLUSIONS: The sORP may play a role in age-related decreases in semen parameters (volume, motility, and BCF). The rate of sORP positivity increased significantly after 34 years of age.

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).