The retrieved oocyte will be inseminated conventionally or by ICSI, depending on the semen parameters. ICSI is advised if the total motile sperm number after sperm preparation < 0.2 million, sperm morphology by strict criteria < 3% or fertilization rate < 30% in previous IVF cycles with conventional insemination. One to two embryos will be replaced on day 2-5 after oocyte retrieval. Luteal phase support will be started according to the standard protocol of the centre. Patients will be followed up for urinary pregnancy test 16 days after embryo transfer. Patients with a positive pregnancy test will have transvaginal ultrasound scan performed 10-14 days later and are referred for antenatal care at 8-10 weeks gestation. The remaining embryos will be frozen. Pregnancy outcome will be monitored.