[Artificial reproductive techniques: comparison of embryo transfer on day two or day three]

Due to the lack of adequate media which could support embryo in vitro development in early IVF procedure day 2 transfer has been a dominated procedure. However, day 3 transfers more physiological to in vivo conditions and may pre-select embryos with better prognosis.

A studied group was 131 infertile couples subjected to classical IVF or ICSI in proportion, and day 2 transfer was performed in 67 cycles, while day 3 transfer in 64 cycles. Average age of both groups was comparable--around 31 years of age. In all cycles the long protocol of stimulation was applied. For in vitro culture--MediCult (Denmark) medium was employed.

There were no statistical differences in proportion of class A to B embryos in a group with day 2 transfer (respectively: 65.2% and 30.4%) and in a group with day 3 transfer (respectively: 63.5% and 30.8% for A and B embryos). Similar rates of pregnancies per cycle were obtained--25.4% and 25.0% respectively for day 2 and day 3 transfer. There were also no statistical differences in implantation rate per cycle (28% and 27% respectively).

Performed analysis did not allow to indicate statistical significant differences in laboratory and clinical data for both studied groups. However, retrospective study does not exclude subjective criteria that could be applied to individual will of the patient regarding a day of transfer.