ABSTRACT
The relatively poor success rates after in vitro fertilization (IVF) in the early days have made multiple embryo transfer generally accepted to compensate for low implantation rates. The multiple pregnancies that originated from multiple embryo transfer have long been considered an unavoidable and acceptable price to be paid for a reasonable pregnancy rate. The quality of the IVF laboratory has gradually improved, increasing the success rates; however, the incidence of multiple pregnancies has also increased. The efforts initiated in the early 1990s by Staessen and colleagues have led to the complete disappearance of triplet pregnancies, while maintaining a steady pregnancy rate when, in a selected population, a reduction of three to two embryos for transfer was performed5, 6. However, the twin pregnancy rate unfortunately remained unaffected.
