Late intracytoplasmic sperm injection in unexpected failed fertilization in vitro: diagnostic or therapeutic?

Fertil Steril. 1995 Apr;63(4):816-9. doi: 10.1016/s0015-0282(16)57487-1.


Objective: To evaluate fertilization potential of 24-hour-old unfertilized oocytes using intracytoplasmic sperm injection and the pregnancy potential of resultant embryos.

Design: Prospective observational study.

Setting: Private infertility clinic, London, United Kingdom.

Patients: Fifteen patients with a history of infertility who underwent treatment with IVF and showed failure of fertilization on the day after oocyte retrieval.

Intervention: Assisted fertilization with intracytoplasmic sperm injection was carried out at 24 hours after oocyte retrieval.

Results: A total of 121 metaphase II oocytes were subjected to intracytoplasmic sperm injection. Of these, 9 were damaged (7%), 2 were polyploidic (2%), and 58 showed normal fertilization (48%). Of the latter, 47 cleaved normally (81%). Forty embryos were transferred and three were cryopreserved. One patient conceived (7%) but in this case only one of three embryos transferred was from intracytoplasmic sperm injection.

Conclusion: Late (24 hours) intracytoplasmic sperm injection can give good fertilization and cleavage rates but the potential of the generated embryos to achieve pregnancy seems to be low.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cleavage Stage, Ovum
  • Cytoplasm
  • Embryo Transfer
  • Female
  • Fertilization in Vitro / methods*
  • Humans
  • Male
  • Microinjections
  • Pregnancy
  • Prospective Studies
  • Spermatozoa*
  • Time Factors
  • Treatment Failure