Normal pregnancy resulting from a non-pronuclear oocyte at the time of examination for fertilization

Clin Exp Obstet Gynecol. 2008;35(3):170-1.


Purpose: To report the case of a patient undergoing in vitro fertilization (IVF) in which a non-pronuclear (0PN) oocyte resulted in a normal pregnancy.

Methods: A 36-year-old woman underwent an IVF-embryo transfer treatment cycle.

Results: Four oocytes were retrieved for insemination by IVF. Examination for fertilization revealed two polypronuclearpolygynic and two non-pronuclear oocytes. The non-pronuclear oocytes were observed further for development. One embryo developed from the non-pronuclear cohort and was transferred at the 8-cell stage on day 3. Subsequently, a pregnancy developed, and resulted in the delivery of a healthy term infant.

Conclusions: Non-pronuclear oocytes may represent a source of developmentally competent embryos, and further observation of this cohort should be considered, particularly in situations involving a low yield of oocytes at retrieval.

MeSH terms

  • Adult
  • Embryo Transfer
  • Female
  • Fertilization in Vitro*
  • Humans
  • Infant, Newborn
  • Oocytes / cytology*
  • Oocytes / physiology
  • Ovulation Induction
  • Pregnancy
  • Term Birth