Transfer of blastocysts and morulae on day 5.
OBJECTIVE
To limit the number of embryos transferred and reduce high-order multiple pregnancies without compromising a patient's opportunity to become pregnant.


METHODS
Retrospective, nonrandomized analysis of embryo development and patient outcome when embryos were transferred on day 5.


METHODS
Private practice.


METHODS
Women undergoing in vitro fertilization (IVF) treatment.


METHODS
Extend embryo culture to day 5 before embryo transfer (ET) to reduce the number of embryos transferred and minimize high-order multiple pregnancies.


METHODS
Clinical pregnancy rate (CPR), implantation rate (IR), and live born rate (LBR) from expanding (expanded blastocysts and blastocysts) and nonexpanding (early blastocysts and morulae) embryos transferred on day 5.


RESULTS
Approximately 60% of patients had expanding embryos (EXE) on day 5. Forty percent of patients having an ET had transferable non-expanding embryos (NEE). Patients with EXE had higher CPR and LBR compared to patients with NEE. Implantation rate and multiple pregnancy rate (MPR) were also higher for patients with EXE. The miscarriage rate (MCR) for patients with EXE and NEE was not different. Approximately 5.5% of patients did not have an ET, with most (>98%) of the ET failures from patients with <==3 two pronuclei (2PN) embryos. The number of 2PN embryos had an effect on CPR, LBR, MPR, and the number of patients having cryopreservation.


CONCLUSIONS
Day 5 ET allows for the selection of embryos with the highest implantation potential as evidenced by acceptable pregnancy rates for patients with either EXE or NEE, without the need to transfer more than two embryos.
Wilson
Michael
M
Reproductive Resource Center of Greater Kansas City, P.A., 12200 West 106th Street, Overland Park, KS 66215, USA. mwilson@rrc.com
Hartke
Kathy
K
Kiehl
Michelle
M
Rodgers
Jonetta
J
Brabec
Celeste
C
Lyles
Rodney
R
D001755:Blastocyst / Q000502:physiology; D010064:Embryo Implantation / Q000502:physiology*; D004624:Embryo Transfer / Q000706:statistics & numerical data*; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007231:Infant, Newborn; D009028:Morula / Q000502:physiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D012189:Retrospective Studies