Monopaternal superfecundation of quintuplets after transfer of two embryos in an in vitro fertilization cycle

Objective: To present the first genetically proven identity of quintuplets in an IVF treatment cycle after transferring only two embryos. Design: Case report. Setting: IVF unit and obstetrics department of university-affiliated general hospital. Patient(s): Twenty-five-year-old patient undergoing IVF treatment for unexplained infertility. Intervention(s): In vitro fertilization with intracytoplasmic sperm injection performed on 50% of oocytes, resulting in successful production of nine early-cleavage embryos. Transfer of two embryos on day 3 and freezing of the remaining embryos. Main Outcome Measure(s): Development of five separate embryonic sacs. Fetal reduction of three embryos at 12 weeks of gestation. Result(s): Successful completion of the twin pregnancy and full genetic analysis of the three embryos and the twins that were born at term. Conclusion(s): Despite transferring only two embryos, superfecundation occurred, resulting in five embryos. Genetic analysis can be used to determine paternity and identity of all the embryos. (Fertil Steril(R) 2001;76: 621-3. (C) 2001 by American Society for Reproductive Medicine).