Individual variation of the percentage of Y-chromosome bearing sperm content in human ejaculates.

The study aimed to determine the variation of Y-chromosome-bearing sperm content among individual ejaculates. A real-time polymerase chain reaction (qPCR) with unique primers was developed and used to calculate the percentage of Y-chromosome-bearing sperm in individual ejaculates from 50 randomly selected men. There was a significant difference in the overall mean ± SD between the proportion of Y-chromosome-bearing sperm and X-chromosome-bearing sperm (45.36 ± 7.88 vs. 54.42 ± 7.88). Of the 50 ejaculates, 17 had more than, and 14 had less than the 99% confidence interval of the mean of the Y-chromosome-bearing sperm (45.58 ± 2.87). These results suggest that the inconsistency in sperm-based sex-selection outcomes appears to be a function of differences in the ejaculates and highlights the need for further study in environmental and genetic factors contributing to X or Y bearing spermatozoan instability.Abbreviations: qPCR: real-time polymerase chain reaction; ROS: reactive oxygen species; DTT: dithiothreitol; SRY: sex-determining region Y.

Frequency of embryo multinucleation detected by time-lapse system and its impact on pregnancy outcome.

OBJECTIVE: To compare the detection rate of multinucleation with the time-lapse system and conventional control timing proposed by European Society of Human Reproduction and Embryology (ESHRE) consensus and evaluate its impact on pregnancy rates. DESIGN: Retrospective study. SETTING: A private IVF center. PATIENT(S): A total of 686 embryos from 511 intracytoplasmic sperm injection (ICSI) cycles. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): A time-lapse system was used to acquire embryo images until ET; the stored data were reviewed for the presence and persistence of multinucleation. The detection rate of multinucleation was compared with ESHRE/ALPHA consensus-proposed embryo evaluating times (23 ± 1, 26 ± 1, 44 ± 1 hours). Morphokinetic characteristics of multinucleated embryos and the effect of multinucleation on pregnancy rate were researched. RESULT(S): Multinucleation was detected in 159 embryos of 145 ICSI cycles. Using ESHRE/ALPHA consensus embryo evaluating times, only 44 (27.6%) out of 159 multinucleated embryos could be identified. In cycles with multinucleated ETs compared with cycles with no multinucleated embryos, clinical pregnancy rates (respectively, 23.4 vs. 44) and implantation rates (respectively, 23.3 vs. 43.6) were significantly lower. Time to 2-cell, 4-cell, and 6-cell stage was significantly longer in multinucleated embryos. Patient age (odds ratio [OR], 0.95; confidence interval [CI], 0.92-0.98) and presence of multinucleation (OR, 0.37; CI, 0.24-0.56) were the only significant predictors of clinical pregnancy rate. CONCLUSION(S): The time-lapse monitoring system seems to be a valuable tool to identify all cases with multinucleation. We conclude that the detection of multinucleation by time-lapse monitoring is associated with lower implantation and clinical pregnancy rates.