Hypo-osmotic swelling test and unexplained repeat early pregnancy loss

Aim: To study the relationship of various sperm characteristics and hypo-osmotic swelling test (HOS test) with repeat unexplained early pregnancy loss. Methods: Semen samples from husbands of 74 couples with a history of repeat early pregnancy loss (group A) were analyzed according to World Health Organization criteria, and a HOS test was performed in each case. Semen samples from 65 husbands with proven fertility (group B) were also studied for comparison. Results: No statistically significant differences were noted in the age of the husbands, sperm concentration, sperm morphology and percent motile sperm between groups A and B. The mean HOS test scores of the two groups were significantly different (group A: 60.4%; group B: 76.9%; P = 0.01 [normal value: > 60%]). In group A, 33.8% of cases (25/74) and in group B, 12.3% of cases (8/65) showed low HOS test scores. Conclusion: The sperm HOS test may be helpful to screen for any paternal factor associated with repeat embryonic or early fetal loss and in a resource-poor setting, and may be utilized in any clinical laboratory.