DIZYGOTIC TWIN PREGNANCY AFTER INTRACYTOPLASMIC SPERM INJECTION OF 1 DAY-OLD UNFERTILIZED OOCYTES

We report on a case where late intracytoplasmic sperm injection (ICSI) on unfertilized oocytes after standard in-vitro fertilization (IVF) c ycles resulted in a dizygotic twin pregnancy. Fifteen oocytes were har vested from a patient with a history of salpingotomy. After a single c ycle of IVF, only one oocyte showed two pronuclei. Subsequently ICSI w as performed on six unfertilized metaphase II oocytes, and three of th ese oocytes showed two pronuclei. Three fertilized embryos were transf erred (two derived from ICSI and one from IVF). A normal twin pregnanc y resulted, and after delivery of two healthy boys the twins were conf irmed to be dizygotic by DNA analysis of several loci. We conclude tha t at least one of the embryos was derived from the reinsemination by ' second day ICSI'.