Combined intrauterine triplet and ectopic pregnancy following pronuclear embryo transfer in a patient with elevated serum progesterone during ovulation induction.

We present a case of heterotopic pregnancy occurring after ET of pronuclear-stage embryos. This case demonstrates that pronuclear embryos have a good implantation potential and suggests that the potentially adverse effect of high follicular-phase serum progesterone levels on endometrial development might be offset by early ET of pronuclear embryos. This, however, is speculative and deserving of formal scientific evaluation. Finally, we are reminded that heterotopic pregnancy complicates 1 to 3% of IVF-ET pregnancies and that, even with a high index of suspicion, most heterotopic pregnancies are diagnosed after rupture. All assisted reproductive programs should be reminded frequently that ectopic and heterotopic pregnancies do occur and can lead to serious consequences if left undetected.