The hypo-osmotic swelling test and the sperm mucus penetration test in determining fertilization of the human oocyte.

The usefulness of the hypo-osmotic swelling (HOS) test and the sperm mucus penetration (SMP) test as sperm function tests for in-vitro fertilization was analysed in 56 couples. Using logistic regression analysis only the SMP test was independently related to fertilization (P = 0.004), no false negative results were obtained, i.e. no fertilization if sperm from the ejaculate failed to penetrate mucus. The HOS test was of no predictive value. The results justify a further examination of the SMP test in other IVF centres.