Sheryl T. Homa

The association between male infertility and sperm disomy: Evidence for variation in disomy levels among individuals and a correlation between particular semen parameters and disomy of specific chromosome pairs

BackgroundThe association between infertility and sperm disomy is well documented. Results vary but most report that men with severely compromised semen parameters have a significantly elevated proportion of disomic sperm. The relationship between individual semen parameters and segregation of specific chromosome pairs is however less well reported as is the variation of disomy levels in individual men.MethodsIn order to address these questions the technique of fluorescent in-situ hybridisation (FISH) was utilised to determine the disomy levels of chromosomes X, Y and 21 in 43 sperm samples from 19 infertile males. The results generated from this study were analysed using logistic regression.ResultsIn this study we compared levels of sperm concentration, motility and morphology with levels of sperm disomy for chromosome 21 and the sex chromosomes. Our results suggest that there is considerable variation in disomy levels for certain men. They also suggest that oligozoospermic males have significantly elevated levels of sex chromosome disomy but not disomy 21; they suggest that severe asthenozoospermic males have significantly elevated levels of disomy 21 but not sex chromosome disomy. Surprisingly, severe teratozoopsermic males appeared to have significantly lower levels of sperm disomy for both the sex chromosomes and chromosome 21.ConclusionWe suggest that the association between sex chromosome disomy and oligozoospermia may be due to reduced recombination in the XY pairing region and discuss the relevance of our findings for the correlations between sperm disomy and sperm motility and morphology.

Serum is more effective than albumin in promoting human embryo development and implantation.

OBJECTIVE To compare the effects of serum with those of Albuminar-5 (Armour Pharmaceutical Co., Eastbourne, Sussex, United Kingdom) as medium supplements to Earls balanced salt solution (EBSS) for IVF and subsequent embryo development. DESIGN A retrospective study. Gametes and embryos from 318 patients were cultured in the presence of serum (group 1). Gametes and embryos from 130 patients were cultured in the presence of Albuminar-5 (group 2). Embryos obtained from IVF were replaced into the uterus within 48 hours after insemination. Surplus bipronucleate embryos were cultured up to 14 days with either serum or Albuminar-5. SETTING Two tertiary referral fertility clinics; university teaching hospital. PATIENTS Four hundred forty-eight patients with a wide spectrum of causes of subfertility, ranging in age from 24 to 43 years. MAIN OUTCOME MEASURES Fertilization rate, pregnancy rate (PR), implantation rate, and surplus embryo development in vitro. RESULTS The PR for group 1 patients was higher than that of group 2 (27.0% versus 15.4%, respectively). Although fertilization rates were identical in the two groups, cumulative embryo scores and implantation rates were significantly higher in group 1. There was no difference between the groups in age distribution, types of ovarian stimulation, numbers of patients with day 1 or day 2 transfers, or luteal phase support. Of 31 embryos cultured with serum, 54.8% reached the fully expanded blastocyst stage and 25.8% hatched. Of 19 embryos cultured with Albuminar-5, only 5.3% reached the fully expanded blastocyst stage and none hatched. CONCLUSIONS The results suggest that, under certain conditions, serum supplementation yields better results than protein supplementation alone. The latter may be suitable only in conjunction with additional components.