We report the occurrence of triploid preimplantation embryos following in v
itro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in a w
oman with two previously-identified triploid conceptuses which spontaneousl
y underwent fetal demise at 10 and 23 weeks' gestation. An error in materna
l meiosis TI is proposed as the most likely cause. Copyright (C) 2000 John
Wiley & Sons, Ltd.