Fertilization of human oocytes in vitro by spermatozoa from oligozoospermic and normospermic men

Abstract

Sperm were isolated from the semen of oligozoospermic (less than 20 x 10(6) sperm/ml) and normospermic (greater than or equal to 20 x 10(6) sperm/ml) men in an in-vitro fertilization (IVF) programme. Oocytes from the female partners were inseminated with either 75 or 100 x 10(3) motile sperm and checked for fertilization after 16-20 h. A significant reduction in the overall fertilization rate of oocytes was seen for the oligozoospermic group compared to the normospermic group, at both insemination concentrations. In the oligozoospermic group, a fertilization rate of 31% (19/61) was achieved when oocytes were inseminated with 75 x 10(3) sperm, and 38% (9/24) when inseminated with 100 x 10(3) sperm. This compared with rates of 57% (397/696) and 64% (650/1018), respectively, for normospermic cases at both insemination concentrations. No evidence of fertilization was seen in 36% (4/11) and 67% (4/6) of oligozoospermic cases when 75 or 100 x 10(3) sperm were used, compared with values of 13% (17/133) and 9% (20/212), respectively, in normospermic cases. After excluding zero cases, the fertilization rate of oocytes for the oligozoospermic group (75%; 9/12) was similar to the normospermic group (70% 650/935) when 100 x 10(3) sperm were used. However, when 75 x 10(3) sperm were used, the fertilization rate for the oligozoospermic group (41%; 19/46) was significantly lower than that of the normospermic group (62%; 397/645). Following the transfer of embryos into the female partner, clinical pregnancies were diagnosed in 2/7 (29%) oligozoospermic cases and 27/267 (10%) normospermic cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of human zonae from cryopreserved oocytes in a test to assess the binding capacity of human spermatozoa

“…The present study has used routine cryopreservation techniques as a storage method for aged, unfertilized oocytes. This enables oocytes surviving the freeze-thaw processes to be used in an homologous sperm penetration assay (Morroll et al, 1992), whilst those failing to survive can be used in the zona-binding test. In this way, all of the stored oocytes can be utilized without wastage.…”

“…Initially, zona binding was assessed for all oocytes, regardless of whether they survived the freeze-thaw processes. In later cases those oocytes surviving post-thaw were used in an homologous sperm penetration test (Morroll et al, 1992), and only the zonae of non-viable oocytes were used in the sperm-binding assay. Zonae obtained from a single IVFIGIFT treatment cycle were divided equally for testing of sperm-binding by spermatozoa from the fertile control and from patients.…”

“…The routine semen analysis performed in andrology laboratories is considered to be a poor predictor of the fertilizing capacity of spermatozoa (Bostofte et al, 1982;Barlow et al, 1991). For example, whilst oligozoospermic men generally have a reduced chance of achieving fertilization in vitvo, the performance of spermatozoa from each individual varies from total failure to fertilize oocytes to a normal rate of fertilization (Matson et a/., 1989). This has prompted a move away from a simple description of semen quality to the use of tests which assess sperm €unction.…”

“…Whilst inseminated-unfertilized oocytcs can be used in zonabinding tests (Franken et a / . , IWla), we have shown previously that such oocytcs can be cryoprcscrvcd and used following the removal of the zona in a test of the fertilizing capacity of spermatozoa (Morroll et a / . , 1992).…”

A guide to upwardly mobile spermatozoa

“…Two preparations were assessed from each patient's ejaculate: (1) an aliquot of the raw ejaculate; and (2) a sample of the swim-up spermusedfor in vitro fertilization. Preparation of the swim-up sample was as described by Matson et al (1989). Both samples were fixed before examination in isotonic 2 % glutaraldehyde.…”