Does fresh single embryo transfer outcome predict the result of a subsequent vitrified-warmed blastocyst of the same cohort?

Reflecting the current trends, the utilization of frozen-thawed transfer cycles has been steadily increasing worldwide; outcome predictors of these cycles are therefore a major research goal. Our aim was to investigate whether the outcome of a fresh single blastocyst transfer (SBT) can serve as a prognostic factor for the subsequent vitrified-warmed SBT originating from the same cohort. A retrospective cohort study was performed at a single unit. Non-donor fresh cycles were analyzed as predictors of the following vitrified-warmed cycle. Only SBTs were included. Cycles designated to a freeze-all policy and cycles involving pre-implantation genetic analysis were excluded. A total of 1127 vitrified-warmed single blastocyst cycles were included. The indications for artificial reproductive technologies were comparable across the study groups. Vitrified-warmed cycles following a live birth outcome in the fresh cycle were more likely to result in a clinical pregnancy than those following a fresh cycle, which failed to reach a live birth. The same trend was observed for live birth rate following vitrified-warmed transfer in the fresh cycle. After correcting for possible confounders, age and embryo quality were significantly correlated with the chance for a live birth, but the previous fresh cycle did not affect the results. We therefore conclude that after adjustment for age, embryo quality and number of previous oocyte retrieval cycles, the fresh cycle outcome was not a significant influential factor for the following vitrified-warmed cycle.

Predictive value of serum HCG concentrations in pregnancies achieved after single fresh or vitrified-warmed blastocyst transfer.

Possible differences between serum HCG levels in pregnancies achieved after transfer of a single fresh or a vitrified-warmed blastocyst were evaluated. Out of 1130 single blastocyst transfers resulting in positive HCG results, 789 were single fresh blastocyst transfers and 341 single vitrified-warmed blastocyst transfers. The initial serum HCG levels of 869 clinical intrauterine pregnancies were evaluated, 638 after the transfer of a single fresh blastocysts and 231 after the transfer of a single vitrified-warmed blastocysts. The HCG levels from cycles resulting in a clinical intrauterine pregnancy were significantly higher after the transfer of a single vitrified-warmed blastocyst (383 ± 230 IU/l) versus a fresh transfer (334 ± 192 IU/l; P = 0.01). Threshold values for predicting a clinical pregnancy for a fresh blastocyst were 111 IU/l and for a vitrified-warmed blastocyst 137 IU/l. Our study shows that the overall beta-HCG levels are comparable after the transfer of a fresh or vitrified-warmed blastocyst, suggesting that vitrification most probably does not affect the ability of the embryos to produce beta-HCG. This study further shows that when clinicians counsel patients, they should take into account that higher HCG levels are needed after a vitrified-warmed blastocyst transfer to predict a clinical intrauterine pregnancy.

Vitrified-warmed single-embryo transfers may be associated with increased maternal complications compared with fresh single-embryo transfers.

Cryopreservation of embryos allows single-embryo transfer and storage of supernumerary embryos, maximizing cumulative pregnancy rates. The purpose of this retrospective cohort study was to compare pregnancy outcome in singletons born after fresh or vitrified-warmed single blastocyst transfer (SBT). Singleton live births resulting from SBT of fresh or vitrified-warmed embryos were compared. Primary outcomes were perinatal outcomes including small for gestational age (SGA), low birthweight, preterm deliveries (PTD), large for gestational age (LGA) and congenital malformations. Maternal complications included pre-eclampsia, placenta previa, placental abruption, gestational diabetes mellitus (GDM) and chorioamnionitis. Adjustment for confounding factors was performed. Of 1886 fresh SBTs and 1200 vitrified-warmed SBTs during the study period, vitrified-warmed SBTs compared with fresh SBTs resulted in significantly lower clinical pregnancy rate (P < 0.0001). Live birth and miscarriage rates calculated only for pregnancy with known outcome revealed lower live birth rates and higher miscarriage rates for the vitrified-warmed group. Perinatal complications were calculated for clinical pregnancies with known outcomes (12.9% catchment failure was excluded from analysis). The vitrified-warmed group showed a trend toward higher rates of pre-eclampsia, GDM, Caesarean delivery and LGA neonates. Rates of PTD and SGA were comparable. In conclusion, vitrified-warmed SBT might be associated with increased feto-maternal complications.

Observation of the Incidence of Acrosome Reaction in Human Spermatozoa Treated with Mibefradil as a T-type Ca2+i Channels Inhibitor / 대한불임학회지

OBJECTIVE : The sperm acrosome reaction is a Ca2+ -dependent exocytotic event that is triggered by adhesion to the mammalian egg's zona pellucida. Previous studies suggested a role of Ca2+ channels in acrosome reactions. This study was conducted to investigate the T-type calcium channel is operated in acrosome reaction of human spermatozoa. METHOD : Human semen samples were obtained from healthy donors with nomal criteria. The spermatozoa were divided into five groups: Group 1 were non-treated as a control; Group 2 where spermatozoa were exposed to 5 micrometer Ca2+ A23187 (Ca2+i); Group 3 where spermatozoa were exposed 5 micrometer Ca2+i and mibefradil; Group 4 where spermatozoa were exposed 5 micrometer Ca2+i and nifedipine, and Group 5 where spermatozoa were treated with 5 micrometer Ca2+i and both of mibefradil and nifedipine. Spermatozoa in all groups were retrieved after incubation for 15 and 30 minutes at 37degrees C. After staining with PSA-FITC, fluorescence was observed under a fluorescence microscope, and AR was evaluated on a total >100 spermatozoa/side. RESULT AND CONCLUSION : We observed on acrosome reaction inhibition rate in human spermatozoa the various of concentration of mibefradil, nifedipine. Maximum response was noted with 1.0 micrometer mibefradil and the decrease of acrosome reaction inhibition rate 45%. Nifedipine in acrosome reaction inhibition rate was only about 25%. The Ca2+i-induced AR of spermatozoa was significantly suppressed by mibefradil. Incidence of the suppression was depending on concentration of mibefradil. Results from the present study suggest that the human spermatozoa possess T-type channel. The observation that reversible inhibitor of T channels in male germ cells provides a new mechanism of contraceptive action.

Cryopreservation of human immature follicular oocytes / 대한불임학회지

No abstract available.