Prevention of multiple pregnancies by restricting the number of transferred embryos: randomized control study.
BACKGROUND
The high incidence of multiple pregnancies is a major concern in the treatment of infertility by in vitro fertilization (IVF). Risks and costs are associated with multiple pregnancies and it is important to find a way to decrease multiple pregnancies. The standard protocol for IVF includes the transfer of two or three embryos.


METHODS
In this study, we compared the rate of single and multiple pregnancies between patients who received two and three embryos. One hundred and sixty-nine patients were randomly divided into two groups, with 106 cycles of IVF each. Group 1 received two embryos, and group 2 three.


RESULTS
Group 1 had total 40 (37.8%) pregnancies, while group 2 had 29 (27.4%). The number of ongoing pregnancies was 33 (31.1%) in group 1 and 26 (24.5%) in group 2. The number of baby-take-home was 32 (30.1%) in group 1 and 26 (24.5%) in group 2. These results show that there was no significant difference between the two groups in both the total and ongoing pregnancies. On the other hand, the number of twin pregnancies was 6 (15.0%) in group 1 and 12 (41.4%) in group 2, showing a significant difference. Group 1 had no triplet pregnancies, while Group 2 had two.


CONCLUSIONS
We conclude that the transfer of two embryos reduces the incidence of multiple pregnancies while maintaining an acceptable rate of pregnancy in IVF.
Komori
Shinji
S
Department of Obstetrics and Gynecology, Hyogo College of Medicine, 1-1 Mukogawa-cho, 663-8501, Nishinomiya, Hyogo, Japan. komor615@hyo-med.ac.jp
Kasumi
Hiroyuki
H
Horiuchi
Isao
I
Hamada
Yukari
Y
Suzuki
Chizu
C
Shigeta
Minoru
M
Koyama
Koji
K
D004624:Embryo Transfer / Q000592:standards*; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects* / Q000379:methods; D006801:Humans; D007246:Infertility / Q000628:therapy*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple