To investigate the role of the 'male factor' in the pathogenesis of recurrent spontaneous abortion (RSA), especially sperm morphology abnormalities, 120 previously selected couples with unexplained RSA were studied for sperm parameters retrospectively and prospectively. The patients were subdivided into three subgroups, depending on their reproductive outcome during the 3 years of follow-up study: (i) 48 RSA couples who achieved a successful pregnancy; (ii) 39 RSA couples who experienced further abortions, and (iii) 33 RSA couples who experienced infertility during the follow-up period. A semen analysis was performed twice at the time of inclusion in this study, and twice again during the 3 year follow-up period. No significant differences in semen parameters were observed between RSA males and fertile controls. Instead, significant differences were observed between the group of RSA couples who experienced infertility during the follow-up and the other two groups (RSA couples who achieved successful pregnancy and RSA couples who experienced miscarriages and no live birth during the follow-up) for sperm concentration (P < 0.01 and P < 0.01 respectively), sperm motility (P < 0.01 and P < 0.01 respectively) and sperm morphology abnormalities (P < 0.01 and P < 0.01 respectively). Sperm morphology abnormalities do not seem to be involved in determining RSA; instead, they are an aetiological factor in determining infertility in patients, along with the other semen parameters, in the RSA couple's subsequent reproductive life. Semen analysis is an important test in the clinical management of RSA couples.

Our findings are in accordance with the hypothesis of a tropho-decidual origin of this marker, suggesting its possible usefulness in the prognostic evaluation of first trimester threatened abortion.

The results suggest that gene(s) disadvantageous for reproduction may exist between the HLA-B and -DR chromosomal region which influences the pregnancy outcome in RSA couples, and that HLA-antigen sharing itself does not influence the outcome.

These data represent a confirmation of the existence of a MHC linked gene(s) influencing the GTT development.

A luteal phase defect (LPD) is a clinical problem leading to infertility and is characterized by reduced progesterone levels during the luteal phase. Serum lipoperoxidation is an expression of cellular hypoxic damage occurring under all stress-oxidative conditions. Forty-eight consecutive infertility patients, according to the infertility class II of the WHO classification, underwent clinical observation. Twenty-five patients ovulated constantly with a normal luteal phase, while the other 23 had a LPD, hormonally and histologically assessed. The luteal phase was monitored biochemically by titration of progesterone, oestradiol, and serum lipid peroxides during the ovulatory period and 6–12 days after ovulation. The mean plasmatic concentration of oestradiol was not statistically different between the LPD and the normal-cycle groups, while a statistically significant difference was found for progesterone plasmatic concentrations between the LPD and the normal-cycle groups (p < 0.05); a greater statistical difference was also found in the mean serum lipoperoxide titration (p < 0.001). These findings suggest that serum lipoperoxidation titration may be a useful tool in the study of the interactions between hormonal milieu and sympathetic activity.