Natural selection between day 3 and day 5/6 PGD embryos in couples with reciprocal or Robertsonian translocations.

PURPOSE: For translocation carriers, preimplantation genetic diagnosis (PGD) provides the opportunity to distinguish between normal/balanced and unbalanced embryos prior to implantation and, as such, increases the likelihood of a successful ongoing pregnancy. The data presented here compares autosomal reciprocal and Robertsonian translocation segregation patterns in day 3 versus day 5/6 IVF-PGD embryos to determine if there is a difference in the chromosome segregation patterns observed at these developmental time points. METHODS: A retrospective analysis on PGD translocation carriers at Monash IVF was performed. Segregation patterns were compared between day 3 and day 5/6 embryos to ascertain whether selection against malsegregants exists. RESULTS: For reciprocal translocations, 1649 day 3 embryos (139 translocations) from 144 couples and 128 day 5/6 embryos (59 translocations) from 60 couples were analysed. Day 3 segregation analysis showed that 22.3% of embryos were normal/balanced (consistent with 2:2 alternate segregation) and 77.7% were unbalanced (malsegregation). Day 5/6 segregation analysis showed that 53.1% of embryos were normal/balanced and 46.9% were unbalanced. For Robertsonian translocations, 847 day 3 embryos (8 translocations) from 54 couples and 193 day 5/6 embryos (6 translocations) from 31 couples were analysed. Day 3 segregation analysis showed that 38.7% of embryos were normal/balanced (consistent with 2:1 alternate segregation) and 61.3% were unbalanced. Day 5/6 segregation analysis showed that 74.1% of embryos were normal/balanced and 25.9% were unbalanced. CONCLUSIONS: This data demonstrates an increase in the proportion of genetically normal/balanced embryos at day 5/6 of development. This suggests a strong natural selection process between day 3 and day 5/6 in favour of normal/balanced embryos. These findings support performing PGD testing on day 5/6 of embryo development.

Supersensitive fluorescent semen analysis: validation on azoospermic and oligozoospermic samples.

OBJECTIVE: To compare the clinical utility of a supersensitive fluorescent semen analysis (SSSA) procedure published by Cooper et al. (2006) with a conventional World Health Organization (WHO)-based semen analysis technique in males with severe oligozoospermia or azoospermia who are undergoing fertility assessment. DESIGN: Prospective single-center study. SETTING: IVF clinic. PATIENT(S): Patients attending an infertility clinic for semen analysis. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Presence of spermatozoa in the ejaculate. RESULT(S): Semen samples from 100 men were analyzed using conventional WHO 4th Edition semen analysis and determined to be either severely oligozoospermic or azoospermic (reported lower limit of detection of 0.1 million sperm/mL). An aliquot of the same unprocessed sample was also analyzed using the SSSA protocol (reported lower limit of detection of approximately 8000 sperm/mL). The SSSA method confirmed the results of conventional semen analysis in 77% of cases. In 22% of cases, sperm were identified only using SSSA. Overall, SSSA was capable of identifying the presence of sperm in significantly more samples than conventional semen analysis. CONCLUSION(S): The reliable differentiation of extreme oligospermia from azoospermia has profound implications in fertility management. This paper provides the first data comparing sperm detection rates using SSSA or conventional WHO-based approaches in extreme oligozoospermic and azoospermic men in an IVF setting. Results indicate that approximately one in four men classified as azoospermic by conventional semen analysis may actually have sperm present. The improved sensitivity of the SSSA technique may be of significant benefit to patients, particularly in fertility and assisted reproductive technique decision making.