Natural-cycle in vitro fertilization combined with in vitro maturation of immature oocytes is a potential approach in infertility treatment.

To describe pregnancies and live births that resulted from IVF of mature oocytes retrieved from dominant follicles in a natural cycle combined with in vitro maturation (IVM) of immature oocytes retrieved from small follicles. Case reports. McGill Reproductive Center, Royal Victoria Hospital, McGill University. Three women with normal ovaries or polycystic ovaries who underwent infertility treatment. Administration of s.c. hCG (10,000 IU) 36 hours before oocyte retrieval in a natural cycle. After aspiration of all follicles, mature oocytes were inseminated immediately; immature oocytes were matured in vitro, inseminated by intracytoplasmic sperm injection (ICSI), and then the embryos transferred. Pregnancy and live birth. Three pregnancies (two live births and one ongoing at time of writing) were achieved after the combination of natural-cycle IVF with IVM after transfer of the resulting embryos. Natural-cycle IVF combined with IVM might be a new approach to IVF treatment for women with various causes of infertility.