Aim : This study was carried out to establish criteria for the elective transfer of two good-quality embryos to reduce high-order multiple pregnancy rates. The pregnancy and multiple pregnancy rates per transfer were retrospectively analyzed in 128 in vitro fertilization and embryo transfer (IVF-ET) cycles. Results : The analysis revealed that the pregnancy and multiple pregnancy rates were 26.6% (34 of 128) and 23.5% (eight of 34), respectively. Five twin and three triplet pregnancies were included. The pregnancy rates in women 29 years old and younger, 30-34 years, 35-39 years, and 40 years and older were 21.2 (seven of 33), 37.0 (17 of 46), 25.8 (eight of 31), and 11.1% (two of 18), respectively. There was a significant difference of the pregnancy rates between 30 and 34-year-old and 40-year-old and older women (P < 0.05). The multiple-pregnancy rate in women 40 years and older was 0%. Three triplet pregnancies were established only in the first attempt of IVF-ET. The pregnancy rates in women, to whom good-quality embryos (0-4) were transferred, were 0% (none of 12) for 0, 17.2% (five of 29) for one, 41.2% (seven of 17) for two, 30.8% (12 of 39) for three, and 32.3% (10 of 31) for four and more embryos, respectively. The multiple pregnancy rates in women who had good-quality embryos of one, two, three, and four and more transferred were 0% (none of five), 23.5% (four of seven), 16.7% (two of 12), and 20.0% (two of 10), respectively. Conclusion : The criteria for the elective transfer of two good-quality embryos were established as follows: age < 40 years, a first treatment cycle, and more than three good-quality embryos available for transfer. After the application of the established criteria, the overall pregnancy and multiple pregnancy rates were 30.4% (14 of 46) and 14.3% (two of 14), respectively, which was satisfactory as compared with those in the 128 IVF-ET cycles before application of the criteria. An elective transfer of two good-quality embryos can be highly recommended to avoid high-order multiple pregnancies in subjects with the established criteria. (Reprod Med Biol 2002; 1: 23-29).
Keywords: elective transfer of two embryos; embryo quality; in vitro fertilization–embryo transfer; multiple pregnancies.