Abstract
Purpose: Tripronucleate (3pn) development after conventional insemination (CONV) or ICSI was analyzed to estimate the rate of second polar body retention giving rise to 3pn formation.
Methods: Data from 453 consecutive IVF cycles were reviewed during a 6-month period. Mature oocytes were monitored in ICSI (n = 3195) and CONV (n = 2274) groups by fertilization assessment 16–18 h post-insemination. Ovulation induction protocols and in vitro culture conditions remained constant during the study interval.
Results: Normal (2pn) fertilization occurred in 74.2% and 70.5% for CONV and ICSI groups, respectively (p < 0.003). 1pn formation was observed in 4.5% of CONV oocytes, and 2.5% of ICSI oocytes (p < 0.001); 3pn formation was 8.1% in the CONV group, and 2.5% in the ICSI group (p < 0.0001). We observed 4pn formation in 0.4% of oocytes in the CONV group, but in only 0.04% of oocytes fertilized with ICSI (p < 0.007). Cellular degeneration occurred in 2.4% of oocytes inseminated conventionally, and in 3.5% of oocytes fertilized by ICSI (p = 0.02). Maternal age did not impact pronuclear status.
Conclusions: We found the 3pn formation rate after ICSI to be approximately one-third that observed in the CONV group. Extrapolating the ICSI data to the CONV data, it may be inferred that 2.5% of 3pn development after CONV was due to second polar body retention. This suggests that 5.6% of CONV oocytes showed dispermic fertilization. Decreasing oocyte quality with increasing maternal age had no apparent influence on any of the fertilization outcomes.
Keywords: Fertility, fertilization, oocyte, reproductive techniques
Full Text
The Full Text of this article is available as a PDF (168.7 KB).
References
- 1.Staessen C, Van Steirteghem A. The chromosomal constitution of embryos developing from abnormally fertilized oocytes after intracytoplasmic sperm injection and conventional in-vitro fertilization. Hum Reprod. 1997;12:321–327. doi: 10.1093/humrep/12.2.321. [DOI] [PubMed] [Google Scholar]
- 2.Spandorfer SD, Avrech OM, Colombero LT, Palermo GD, Rosenwaks Z. Effect of parental age on fertilization and pregnancy characteristics in couples treated by intracytoplasmic sperm injection. Hum Reprod. 1998;13:334–338. doi: 10.1093/humrep/13.2.334. [DOI] [PubMed] [Google Scholar]
- 3.Veeck LL (ed): An Atlas of Human Gametes and Conceptuses: An Illustrated Reference for Assisted Reproductive Technology. New York, Parthenon Publishing Group, 1999
- 4.Balakier H. Tripronucleate human zygotes: The first cell cycle and subsequent development. Hum Reprod. 1993;8:1892–1897. doi: 10.1093/oxfordjournals.humrep.a137955. [DOI] [PubMed] [Google Scholar]
- 5.Munné S, Tang YX, Grifo J, Cohen J. Origin of single pronucleated human zygotes. J Assist Reprod Genet. 1993;10:276–279. doi: 10.1007/BF01204942. [DOI] [PubMed] [Google Scholar]
- 6.Palermo GD, Munné S, Colombero LT, Cohen J, Rosenwaks Z. Genetics of abnormal human fertilization. Hum Reprod. 1995;10:120–127. doi: 10.1093/humrep/10.suppl_1.120. [DOI] [PubMed] [Google Scholar]
- 7.Sultan KM, Munné S, Palermo GD, Alikani M, Cohen J. Chromosomal status of uni-pronuclear human zygotes following in-vitro fertilization and intracytoplasmic sperm injection. Hum Reprod. 1995;10:132–136. doi: 10.1093/humrep/10.1.132. [DOI] [PubMed] [Google Scholar]
- 8.Kola I, Trounson A, Dawson G, Roger P. Tripronucleate human oocytes: Altered cleavage patterns and subsequent karyotypic analysis of embryos. Biol Reprod. 1987;37:395–401. doi: 10.1095/biolreprod37.2.395. [DOI] [PubMed] [Google Scholar]
- 9.Balakier H, Squire J, Casper RF. Characterization of abnormal one pronuclear human oocytes by morphology, cytogenics and in-situ hybridization. Hum Reprod. 1993;8:402–408. doi: 10.1093/oxfordjournals.humrep.a138060. [DOI] [PubMed] [Google Scholar]
- 10.Macas E, Imthurn B, Roselli M, Keller PJ. Chromosome analysis of single-and multipronucleated human zygotes produced after the intracytoplasmic sperm injection procedure. J Assist Reprod Genet. 1996;13:345–350. doi: 10.1007/BF02070150. [DOI] [PubMed] [Google Scholar]
- 11.Grossmann M, Calafell JM, Brandy N, Vanrell JA, Rubio C, Pellicer A, Egozcue J, Santalo J. Origin of tripronucleate zygotes after intracytoplasmic sperm injection. Hum Reprod. 1997;12:2762–2765. doi: 10.1093/humrep/12.12.2762. [DOI] [PubMed] [Google Scholar]
- 12.Plachot M, Crozet N. Fertilization abnormalities in human in-vitro fertilization. Hum Reprod. 1992;7:89–94. doi: 10.1093/humrep/7.suppl_1.89. [DOI] [PubMed] [Google Scholar]
- 13.Palermo GD, Alikani M, Bertoli M, Colombero LT, Moy F, Cohen J, Rosenwaks Z. Oolemma characteristics in relation to survival and fertilization patterns of oocytes treated by intracytoplasmic sperm injection. Hum Reprod. 1996;11:172–176. doi: 10.1093/oxfordjournals.humrep.a019012. [DOI] [PubMed] [Google Scholar]
- 14.Rosenbusch B, Schneider M, Glaser B, Brucker C. Cytogenetic analysis of giant oocytes and zygotes to asses their relevance for the development of digynic triploidy. Hum Reprod. 2002;17:2388–2393. doi: 10.1093/humrep/17.9.2388. [DOI] [PubMed] [Google Scholar]
- 15.Palermo G, Munné S, Cohen J. The human zygote inherits its mitotic potential from the male gamete. Hum Reprod. 1994;9:1220–1225. doi: 10.1093/oxfordjournals.humrep.a138682. [DOI] [PubMed] [Google Scholar]
- 16.Gras L, Trounson AO. Pregnancy and birth resulting from transfer of a blastocyst observed to have one pronucleus at the time of examination for fertilization. Hum Reprod. 1999;14:1869–1871. doi: 10.1093/humrep/14.7.1869. [DOI] [PubMed] [Google Scholar]