Human Reproduction 2004 19(9):2174; doi:10.1093/humrep/deh480
The merits of blastocyst versus cleavage stage embryo transfer: a Cochrane review
Hum. Reprod., 19, 795–807, 2004
The authors wish to point out the following about their paper published in Human Reproduction 19/4:
We have been contacted by a trial author concerning the above review. The randomised controlled trial (RCT) published by Frattarelli et al 2003
entitled "Blastocyst transfer decreases multiple pregnancy rates in in-vitro fertilization cycles: a randomized controlled trial" (2), has been incorrectly listed in the excluded trials category Table 1. This RCT is indeed a high quality trial reporting valuable live birth rate data per couple and fits the inclusion criteria for meta-analysis. The trial by Frattarelli et al (2) will be included in an update of the Cochrane library version that is currently under way and due to be published by the end of 2004 (3).
Results of the updated meta-analysis including this additional trial (2) are as follows:
Day 2/3 versus Day 5/6:
- Live birth rate per couple: 36.6% vs 44.4% (Peto OR 0.72, 95% CI 0.44- 1.17)
- Pregnancy rate per couple: 39.8% vs 43.2% (Peto OR 0.88, 95% CI 0.69- 1.12)
- Pregnancy rate per couple where fewer blastocysts than cleavage stage embryos were transferred: 39.3% vs 42.0% (Peto OR 0.93 95% CI 0.45- 1.94)
- Pregnancy rate per couple (good prognosis patients): 46.0% vs 47.4% (Peto OR 0.94, 95% CI 0.71-1.24)
- Multiple pregnancy rate per couple: 14.4% vs 17.1% (Peto OR 0.82, 95% CI 0.57- 1.19)
- Multiple pregnancy rate per couple where fewer blastocysts than cleavage stage embryos were transferred: 15% vs 18.8% (Peto OR 0.77, 95% CI 0.49 -1.22)
- There are no major differences between published data and this re-analysed data.
Inclusion of the data from Frattarelli et al (2) in our meta-analysis reinforces the conclusions stated in our paper: that the current evidence does not support a widespread change of practice from cleavage stage to blastocyst transfer to improve pregnancy rates (1,3). Although not confirmed by our meta-analysis, this study does highlight, however, the important possibility of reducing multiple births, yet maintaining a comparable pregnancy rate, by a policy of transferring fewer blastocysts than cleavage stage embryos (2), depending upon the success of blastocyst culture at any given clinic. We wish to thank Dr Frattarelli and his group for their prompt correspondence and understanding regarding this omission.
Debbie A Blake PhDa,b
Michelle Proctor MA (Hons)a,c
Neil P Johnson CREI FRANZCOGa,c,d
aCochrane Menstrual Disorders & Subfertility Group Editorial Base, Obstetrics & Gynaecology Department, National Women's Hospital, Auckland
bAuckland University of Technology
cUniversity of Auckland
dFertility PLUS, Auckland, New Zealand
References
Blake DA, Proctor M and Johnson NP (2004) The merits of blastocyst versus cleavage stage embryo transfer: a Cochrane review. Hum Reprod 19, 795–807.
Frattarelli JL, Leondires MP, McKeeby JL, Miller BT and Segars JH (2003) Blastocyst transfer decreases multiple pregnancy rates in in vitro fertilization cycles: a randomized controlled trial. Fertil Steril 79, 228–229.[CrossRef][Web of Science][Medline]
Blake D, Proctor M, Johnson N and Olive D (2003) Cleavage stage versus blastocyst stage embryo transfer in assisted conception (Cochrane Review). The Cochrane Library Issue 3, Oxford Update Software.
CiteULike 
Connotea 
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||