[Effect of the number of transferred embryos on multiple pregnancy]

The aim of this retrospective study was to assess the influence of the number of transferred embryos on multiple pregnancy.

Retrospective clinical study.

Department of Obstetric and Gynecology FN UP, Olomouc.

Over the last seven years 572 embryotransfers (ET) have been performed in our centre.

Of the 173 pregnancies (P) achieved there were 56% singletons, 35% twins and 9% triplets. One embryo was transferred in 10% of cases and all 8 pregnancies (15% P/ET) ended with a live birth. Two embryos were transferred in 17% of cases. The pregnancy rate was 20% P/ET, 55% of pregnancies were twins and 10% pregnancies were lost in abortion or ectopic pregnancy. Three embryos were transferred in most cases (62%). The pregnancy rate was the highest in this group (36% P/ET) with 13% twins and 3% triplets. The overall pregnancy loss was 16%, the highest loss, 27%, recorded in triplets. Four embryos were transferred in 11% of cases. The pregnancy rate decreased to 28% P/ET, as well as the number of twins (6%), while the number of triplets increased slightly (5%). Pregnancy loss occurred only in singleton pregnancies.

We can conclude that in our setting the pregnancy rate increases with a higher number of embryos up to three embryos transferred. Unfortunately, the higher pregnancy rate with three embryos transferred is on the expense of a higher risk and losses due to multiple pregnancy. Therefore we recommend to transfer two embryos unless there are some specific reasons.