Objective. We examined which specific factors contributed to the increase in Cesarean delivery rate at our hospital over a 10-year period. Methods. From January 2002 to December 2012, data on the Japanese singleton deliveries at ≥22-week gestation managed at Japanese Red Cross Katsushika Maternity Hospital were collected. Potential factors associated with the increasing Cesarean delivery rate were selected according to previous studies. In this study, the incidences of intrauterine fetal demise, umbilical artery pH <7.1, and severe perineal laceration were calculated for each year. Results. The Cesarean delivery rate at our institution increased significantly during the study period (17.3% in 2002 versus 23.4% in 2012, P < 0.01). During the study period, the Cesarean delivery rates in the cases of nulliparity, preterm delivery, low birth weight (<2,500 g), previous Cesarean deliveries and breech presentation were increased significantly. The incidence of intrauterine fetal demise and low umbilical artery pH was significantly decreased, and a negative correlation was found between the Cesarean delivery rate and the incidence of low umbilical artery pH for each year (r = −0.92, P < 0.01). Conclusion. At our institute, the neonatal outcomes seemed to be improved associated with the increased Cesarean delivery rate between 2002 and 2012.

OBJECTIVE: To evaluate the incidence of ovarian hyperstimulation syndrome (OHSS) in potential hyper ovarian responders in corifollitropin alfa without routine GnRH antagonist protocol.DESIGN: Retrospective cohort study. MATERIALS AND METHODS: Two hundred fifty donors aged 20 -34 years with anti-M€ ullerian hormone (AMH) S2.5 ng/mL were included. According to the number of retrieved oocyte, all donors were divided into two subgroups: normal (retrieved 8-20 oocytes, n¼98) and hyper (retrieved >20 oocytes, n¼152) responders. The hormone levels were monitored for determining whether other additional injections (r-LH or/and r-FSH) were necessary after one corifollitropin alfa shot. Oocyte maturation was achieved by GnRH agonist administration and the oocyte pick-up (OPU) was performed at 36 hours after triggering. The diagnosis of OHSS was based on both clinical symptoms and laboratory results including four key indicators: WBC (Cumm), PLT (10 3 /Cumm), Hb (gm/dL) and Hct (%). The following clinical outcomes from recipients were also analyzed.RESULTS: In hyper responders, significantly higher levels of body weight (52.2 kg vs. 54.0 kg), AMH (6.1 ng/ mL vs. 9.9 ng/ mL), AFC (13.2 vs. 15.4), basal LH (4.0 mIU/ mL vs. 5.4 mIU/ mL), peak E2 (2979 pg/mL vs. 5259 pg/ mL) and retrieved oocytes (15.5 vs. 30.4) were observed. The two groups were comparable in age (24.7 vs. 24.5), basal E2 (38.6 pg/mL vs. 42.4 pg/ mL), peak LH (3.8 mIU/mL vs. 3.5 mIU/ mL)maturation rate (MR , 75.9 % vs. 74.5 %) and total supplemented dosage of r-FSH (496.1 IU vs. 447.2 IU) and r-LH (241.1 IU vs. 249.2 IU). For evaluation of OHSS incidence, the pre-and post-OPU laboratory results including WBC, PLT, Hb and Hct, were monitored, and no clinical significance was found. Therefore, the degrees of OHSS were mainly classified by the clinical symptoms. There were no significant difference in the incidences of mild or moderate OHSS between normal and hyper responders (mild: 6.1% vs. 5.9%, p¼0.95 ; moderate: 5.1% vs. 9.2%, p¼0.21 ). Under this stimulation protocol, most of cases occurred OHSS were mild or moderate in both groups. In addition, the clinical outcomes did not differ between normal and hyper responders.CONCLUSIONS: Accordingly, the most concern of corifollitropin alfa administration is the possibility of relatively higher incidence of OHSS in hyper responders. In this study, the results revealed that the incidence of OHSS is no significantly different between normal and hyper responders even without GnRH antagonist administration. Therefore, with well-monitoring, this patient-friendly protocol, less injection, is also suitable for the potential hyper responders.

The rat, as well as the mouse, is one of the most valuable experimental animals for biomedical and physiological research. There are numerous valuable mutant rats including transgenetic strains. Cryopreservation of rat oocytes and sperm as haploid germ cells is a key technology for banking the genetic resources efficiently. The aim of the present study was to examine survival of vitrified/warmed oocytes and developmental competence of resultant zygotes in the rat. Rats used in the present study were all Wistar rats. Epididymal spermatozoa were frozen as described previously (Seita et al. 2005 Reprod. Fertil. Dev. 18, 256). After thawing, spermatozoa were sonicated to obtain sperm heads for intracytoplasmic sperm injection (ICSI). Oocytes were collected from immature females superovulated with eCG and hCG. Oocytes were equilibrated in 7.5% (v/v) ethylene glycol (EG) + 7.5% (v/v) dimethylsulfoxide (DMSO) + 20% (v/v) FCS in PB1 for 5 min and then transferred into 15.0% EG (v/v) + 15.0% DMSO (v/v) + 20% FCS + 0.5 m sucrose in PB1 (vitrification solution) for 1 min at room temperature (22–24�C). During exposure to the vitrification solution, oocytes were loaded on a Cryotop� (Kitazato Supply Co., Tokyo, Japan). At warming, the film of Cryotop was directly immersed into PB1 containing 0.5 m sucrose and 20% FCS at 37.5�C. The warmed oocytes were washed three times and put into a HEPES-buffered (22 mm) modified R1ECM (310 mOsm) medium. The sperm heads were microinjected intracytoplasmically into the warmed oocytes. Then, presumptive zygotes were transferred surgically into the oviducts of recipient females (Day 0), and Caesarean section of the recipients was performed on Day 22. After vitrification and warming, 245 of 275 (88%) oocytes survived morphologically, 240 of the warmed oocytes were injected, and 156 oocytes (65%) were morphologically normal after the injection. To confirm development to term of zygotes derived from cryopreserved oocytes and sperm, 143 injected oocytes were transferred to 9 recipients, resulting in 3 pregnancies and the generation of one live pup. The results indicate that rat zygotes derived from cryopreserved oocytes and sperm through ICSI can develop to term, and full developmental competence can be preserved in rat oocytes after cryopreservation.

alized window of implantation (WOI). This study aims to closely examine the characteristics of patients who underwent an ERA and compare success rates of patients who transferred a PGT-A euploid embryo with an adjusted WOI and with a standard WOI.MATERIALS AND METHODS: Patients who underwent an ERA at a private fertility clinic in NYC during 2019 and 2020 were included. The outcome of the first programmed FET cycle following the ERA with PGT-A euploid embryo(s) was evaluated for patients with Receptive ERA vs. those with an adjusted WOI due to a non-receptive ERA. Exclusion criteria were untested embryos and natural FET cycles.Continuous variables were measured as mean and standard deviation and compared with a two-sample t-test. Categorical variables were compared with a Fisher test. A p-value of <0.05 was considered statistically significant.RESULTS: A total of 46 PGT-A euploid transfers following an ERA were included. Out of the 46 patients, 23 patients received receptive results, while the other 23 patients were classified as non-receptive (including pre-, early, or post-receptive). The distribution of infertility diagnoses was similar between both groups. A PGT-A euploid FET in the receptive group resulted in a 70% implantation rate and 39% rate of ongoing clinical intrauterine gestation. In the non-receptive group, the rates were respectively 65% and 35% and statistically similar.CONCLUSIONS: Adjusted timing of FET for non-receptive ERA patients produced similar pregnancy rates as patients with a receptive ERA.IMPACT STATEMENT: As the use of ERA tests become more popular, it is important to determine its efficacy and role in routine care. From this retrospective cohort study, the adjusted timing of FET for non-receptive ERA produced similar pregnancy rates as patients with receptive ERA.

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