Is abnormal sperm function an indicator among couples with recurrent pregnancy loss?

Objective: To determine whether or not sperm function parameters are altered in male partners of couples with a history of idiopathic recurrent pregnancy loss (RPL). Design: In comparison with proven fertile volunteers, sperm function parameters like hypo-osmotic swelling (HOS), acrosomal status (AS), and nuclear chromatin decondensation (NCD) were assessed in vitro from male partners of couples with a history of idiopathic RPL. Setting: Infertility clinic and andrology laboratory at National Institute of Health and Family Welfare. Patient(s): Male partners of couples with a history of idiopathic RPL and proven fertile male volunteers (control). Intervention(s): Standard semen analysis, assessment of sperm morphology, and sperm function with tests such as HOS, AS, and NCD. Main outcome measure(s): Sperm paameters, such as HOS, AS, and NCD, were assessed in semen samples from RPL in comparison with the proven fertile control group. Result(s): Semen samples from the idiopathic RPL group showed below normal test scores in 57.1% of the cases for all three sperm parameters. The highest aberration (83% of cases) in sperm attributes was observed in NCD, followed by AS (45.7%) and HOS (42.9%). In contrast, abnormality in sperm morphology was limited to 5.7% of the cases. Subnormal sperm function is directly proportional with subnormal sperm motility (<50%) in 23% of the cases. Even in semen samples with normal sperm motility, sperm function scores were below normal in 31.4% of the RPL group. Conclusion(s): Reduction in test scores of sperm function, like HOS, AS, and NCD, in male partners of couples with idiopathic RPL suggests that sperms with altered or lowered functional competencies, if they fertilize the oocytes, may lead to the development of an unsustainable embryo resulting in early pregnancy loss. Normal sperm motility does not always ensure normal sperm function scores.