Search tips
Search criteria 


Logo of jargspringer.comThis journalToc AlertsSubmit OnlineOpen Choice
J Assist Reprod Genet. 2000 July; 17(6): 349–351.
PMCID: PMC3455394

Blastocyst-ET and Monozygotic Twinning


Purpose: To examine the rate of monozygotic twinning associatedwith blastocyst transfer using commercially available,cell-free culture systems with unmanipulated blastocysts.

Methods: A retrospective analysis was conducted in multipleprivate and academic infertility centers throughout theUnited States, of 199 pregnant patients following in vitrofertilization (IVF) blastocyst embryo transfer (ET). Humanembryos obtained through standard IVF stimulation protocolswere cultured in commercially available, cell-free mediasystems and transferred as blastocysts. The main outcomemeasure was the rate of monozygotic twinning.

Results: A total of 199 blastocyst-ET pregnancies wereachieved during the study period at the fertility centersexamined. Monozygotic twinning was noted in 10/199 (5;pc)of these pregnancies. All were monochorionic diamnionic.

Conclusions: Monozygotic twinning previously has beenreported following IVF, especially in relation to assistedhatching. While blastocyst transfer has been available formany years using coculture, there have been no publishedmulticenter reports of monozygotic twinning associated withunmanipulated blastocysts. In a multicenter analysis, a definiteincrease in monozygotic twinning was seen followingblastocyst-ET. We believe this phenomenon is real and thatthis information should be considered when counselingpatients for treatment.

Full Text

The Full Text of this article is available as a PDF (16K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Gardner DK, Schoolcraft WB, Wagley L, Schenker T, Stevens J, Hesla J. A prospective randomized trial of blastocyst culture and transfer in in-vitro fertilization. Hum Reprod. 1998;13:3434–3440. [PubMed]
2. Milki AA, Fisch JD, Behr B. Two blastocyst transfer has similar pregnancy rates and a decreased multiple gestation rate compared to three blastocyst transfer. Fertil Steril. 1999;72(2):225–228. [PubMed]
3. Alikani M, Noyes N, Cohen J, Rosenwaks Z. Monozygotic twinning in the human is associated with the zona pellucida architecture. Hum Reprod. 1994;9:1318–1321. [PubMed]
4. Derom C, Vlietinck R, Derom R, Van den Berghe H, Thiery M. Increased monozygotic twinning rate after ovulation induction. Lancet. 1987;1(8544):1236–1238. [PubMed]

Articles from Journal of Assisted Reproduction and Genetics are provided here courtesy of Springer Science+Business Media, LLC