Mouse oocytes and embryos were obtained following ovulation induction of (C57B16 x CBA) F1 animals. Zonae pellucidae were exposed to alpha-chymotrypsin in phosphate-buffered medium (PB1) supplemented with 3 mg/ml bovine serum albumin upon a heated stage (37 degrees C) and were observed constantly through an inverted microscope. The endpoint of the bioassay was the limits of the zona no longer being seen clearly at x 200 magnification, and the time taken for each zona to dissolve was recorded. A dose-dependent response in dissolution time was clearly seen, with 1% alpha-chymotrypsin being chosen as the routine working solution. Cryopreservation of 2-cell mouse embryos using propanediol did not cause zona hardening but induced a small and significant softening, as gauged by the time taken for zona dissolution (2181 +/- 167 versus 1864 +/- 82 s). Zona hardening was not suspected to occur after the freezing of human embryos as there was no difference in implantation rates per embryo for in-vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment cycles between fresh [IVF: 63/644 (9.7%); ICSI: 51/330 (15.5%)] and frozen embryos [IVF: 36/458 (7.9%); ICSI: 18/112 (16.1%)]. Conversely, significant hardening of the zonae of mature oocytes was seen following cryopreservation (747 +/- 393 s) compared with freshly ovulated oocytes (151 +/- 68 s). It is concluded that (i) the freezing of murine oocytes with propanediol results in zona hardening, implying a possible benefit of ICSI after the cryopreservation of human oocytes, and (ii) the cryopreservation of embryos is not associated with zona hardening or reduced implantation, making microdissection of the zona in such cases generally unwarranted.
This case report describes the birth of a baby following the transfer of cryopreserved embryos generated from intracytoplasmic sperm injection (ICSI) carried out on the second day after oocyte pick-up of in-vitro-matured metaphase I and germinal vesicle stage oocytes. The couple had a history of three failed intrauterine insemination attempts and reduced fertilization rates in two previous in-vitro fertilization (IVF) cycles. In the IVF-ICSI treatment cycle, 6/11 mature oocytes became fertilized following ICSI on the first day. However, the patient failed to conceive following the transfer of three embryos. Five oocytes were immature (two at metaphase I stage and three with a germinal vesicle) and these were cultured overnight. All had extruded a polar body by the following day and ICSI was therefore performed; four oocytes became fertilized, and were cryopreserved at the pronulear stage in propanediol. In the next treatment cycle, transfer of frozen embryos was planned. The pronuclear zygotes were thawed and cultured for 24 h prior to the transfer of two embryos in a cycle stimulated with low doses of follicle stimulating hormone. This resulted in a pregnancy and the delivery of a healthy baby boy. In-vitro maturation of metaphase I and germinal vesicle oocytes which are routinely collected in IVF-ICSI cycles, followed by second day ICSI fertilization, may provide a valuable source of embryos for infertile couples.
Seminal plasma samples from men undergoing vasovasostomy were analysed for antisperm antibodies using the indirect immunobead test. A pre-operative assessment showed antisperm antibodies of either IgA or IgG class to be present in 9/27 (33.3%) men. A significant increase (P less than 0.05) in the post-operative incidence of the antibodies was seen in the men who achieved patency (27/45, 60%) but not in those men for whom no sperm were seen in the ejaculate (4/10, 40%). After follow-up for a minimum of 1 year, conception rates for couples in which the male partner had achieved patency were similar in the groups with no antibodies detected post-operatively (12/18, 66.7%) or with IgA alone (2/3, 66.7%), but was reduced significantly in the presence of IgG (1/9, 11.1%; P less than 0.05) or IgA + IgG (3/15, 20.0%; P less than 0.01).
A total of 345 couples with non-tubal infertility on an IVF waiting list underwent 702 treatment cycles involving daily intrauterine inseminations of husband's washed spermatozoa (AIH) over 3 days of the periovulatory period, following ovarian stimulation. Pregnancy rates achieved were dependent upon the underlying infertility disorder, with similar rates noted in those with a negative post-coital test (15.8%) or where antispermatozoal antibodies were present in either the male (18.5%) or female (17.1%) partner. These rates were significantly higher than for couples with poor cervical mucus (4.7%), asthenozoospermia (0%), endometriosis (mild, 7.7%; severe, 4.1%) or unexplained infertility (8.5%), while discrete oligozoospermia showed mid-range results (10.3%). Pregnancy outcome revealed a high level of early wastage (33.3%), mainly in the blighted ovum category, however congenital abnormalities (5.6%) were not significantly increased. It is concluded that the procedure of AIH should be considered for infertility due to poor sperm--mucus interaction, antispermatozoal antibodies and simple oligozoospermia, prior to IVF-related treatments.
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