Maximizing pregnancy rates and limiting higher-order multiple conceptions by determining the optimal number of embryos to transfer based on quality.
OBJECTIVE
To define statistical thresholds for the number of embryos to be transferred to achieve an optimal pregnancy rate and keep higher-order multiple conceptions (pregnancy with more than two fetal sacs with cardiac activity) within an acceptable limit.


METHODS
A retrospective review of patient records.


METHODS
Private practice assisted reproductive technology (ART) facility.


METHODS
Seven hundred fifty-four consecutive patients who underwent IVF-ET from 1994-1996.


METHODS
Embryo grading and score system used on day 3 of embryo transfer.


METHODS
Implantation, pregnancy, and multiple conception rates.


RESULTS
For women < or =35 years old, transfer of up to four poor-quality, two fair-quality, or two good-quality embryos is optimal to eliminate any risk of higher-order multiple pregnancies. Transfer of four poor-quality, three fair-quality, or two good-quality embryos is recommended for women 36 to 39 years old. In women who are > or =40 years old, five embryos need to be transferred regardless of embryo quality.


CONCLUSIONS
The mean cumulative embryo score can be used as a reference to determine an optimal number of embryos to transfer and to predict pregnancy outcome.
Hu
Y
Y
Northwest Center for Infertility and Reproductive Endocrinology, Margate, Florida 33063, USA.
Maxson
W S
WS
Hoffman
D I
DI
Ory
S J
SJ
Eager
S
S
Dupre
J
J
Lu
C
C
D000328:Adult; D015331:Cohort Studies; D010064:Embryo Implantation; D004624:Embryo Transfer / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000592:standards; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011272:Pregnancy, Multiple / Q000706:statistics & numerical data*; D012189:Retrospective Studies