How many embryos should be transferred in in vitro fertilization? A prospective randomized study.

OBJECTIVE

To maintain the rate of pregnancy, while suppressing high rank multiple pregnancies by limiting the number of fresh embryos transferred after IVF, in a population selected for potential success.

DESIGN

A prospective, randomized study.

SETTING

Département de Gynécologie Obstétrique, Centre Hospitalo Universitaire, Paris VI, France.

PATIENTS

There were two groups of 28 couples. Women were < or = 35 years of age, with > or = 70% cleavage rate and at least four morphologically regular embryos.

INTERVENTION

On the day of ET, either four fresh embryos were transferred (group 1) or two fresh embryos were transferred and two were frozen for later transfer (group 2).

MAIN OUTCOME

Pregnancy rate and multiple pregnancy.

RESULTS

The pregnancy rate was the same in the two groups with one-third of the high rank pregnancies in group 1 and no pregnancies in group 2.

CONCLUSION

Only two fresh embryos need to be transferred in this selected population.