Received December 28, 1997
Accepted January 16, 1999

Embryo exposure to drugs in pregnancy is a reason for concern, the earlier the exposure the greater the concern. With the widespread use of analogues (GnRH) in the lutheal phase of the cycle prior to the actual hiperestimulation for ln Vitro Fertilization, the risk of embryo exposure to this particular group of drugs is a reality that can not be underestimated. We are reporting two cases where the patients got pregnant during the cycle in which they started daily GnRH from the 21st. day on. They had been emphatically oriented about using condon for the whole duration of that cycle but they were so sure they wouldn't get pregnant unless through ln Vitro techniques that they just didn't do it. Although the numbers in the literature seem to be small, they are there showing a very high percentage of pregnancy wastage (50% in our two cases reported), there doesn't seem to be a final agreement on the safety for the embryo as far as minor or major malformations are concerned.