Blastocyst transfer does not cause a sex-ratio imbalance
Received 31 May 2008; received in revised form 26 July 2008; accepted 29 July 2008. published online 10 November 2008.
Objective
To determine whether either single or double fresh blastocyst transfers result in a sex-ratio imbalance in resulting offspring compared with transfers on day 2 or 3 and whether there is a correlation between rate of embryo development and sex of the embryo.
Design
Retrospective analysis.
Setting
Large IVF center.
Patient(s)
Four hundred thirty-five live births from single fresh ETs for the period January 2005 through July 2007 and 2,043 live births from double ETs for the same period.
Intervention(s)
Statistical analysis performed on sex ratio of offspring resulting from transfers (day 2, day 3, day 4, and blastocyst), as well as on the stage of development reached for each day in culture analyzed on sex of the embryo.
Main Outcome Measure(s)
Sex ratio of offspring by day of transfer. Stage of embryonic development by sex for each day in culture.
Result(s)
There was no difference in sex ratio with blastocyst transfer (single or double). There was no difference in speed of embryonic development at any stage in vitro.
Conclusion(s)
Male embryos do not grow faster than female embryos in culture. Blastocyst transfer does not result in a sex-ratio imbalance in resulting offspring.
aMonash IVF, Monash University, Clayton, Victoria, Australia
bCentre for Women's Health Research, Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
Reprint requests: Gareth Weston, Ph.D., Department of Obstetrics and Gynaecology, Monash University, Level 5 Monash Medical Centre, 246–248 Clayton Road, Clayton, Victoria 3168, Australia (FAX: 61-3-9594-6389).
G.W. has nothing to disclose. T.O. has nothing to disclose. J.C. has nothing to disclose. B.V. has nothing to disclose.
ABSTRACT