Background: European results of assisted reproductive techniques from treatments initiated during 2004 are presented in this eighth report.

Methods: Data were mainly collected from existing national registers. From 29 countries, 785 clinics reported 367,066 treatment cycles including: IVF (114,672), ICSI (167,192), frozen embryo replacement (FER, 71,997), egg donation (ED, 10 334), preimplantation genetic diagnosis/screening (PGD/PGS, 2701) and in vitro maturation (IVM, 170). Overall, this represents only a marginal increase since 2003, due to a huge reduction in treatments in Germany. European data on intrauterine insemination using husband/partner's semen (IUI-H) and donor semen (IUI-D) were reported from 20 countries. A total of 115,980 cycles (IUI-H, 98,388; IUI-D, 17,592) were included.

Results: In 14 countries where all clinics reported to the IVF register, a total of 248,937 ART cycles were performed in a population of 261.6 million, corresponding to 1095 cycles per million inhabitants. For IVF, the clinical pregnancy rates per aspiration and per transfer were 26.6% and 30.1%, respectively. For ICSI, the corresponding rates were 27.1% and 29.8%. After IUI-H, the clinical pregnancy rate was 12.6% in women below 40. After IVF and ICSI, the distribution of transfer of 1, 2, 3 and 4 or more embryos was 19.2%, 55.3%, 22.1% and 3.3%, respectively. Compared with 2003, fewer embryos were transferred, but huge differences still existed between countries. The distribution of singleton, twin and triplet deliveries after IVF and ICSI combined was 77.2%, 21.7% and 1.0%, respectively. This gives a total multiple delivery rate of 22.7% compared with 23.1% in 2003 and 24.5% in 2002. After IUI-H in women below 40 years of age, 11.9% were twin and 1.3% triplet gestations.

Conclusions: Compared with earlier years, the reported number of ART cycles in Europe increased and the pregnancy rates increased marginally, even though fewer embryos were transferred and the multiple delivery rates were reduced.