Prenatal diagnosis in multiple pregnancies.

Multiple pregnancy, with its high rate of fetal loss and increasing incidence, merits greater clinical attention and research. Prenatal diagnosis in multiple pregnancy poses particular difficulties in terms of safety and technique of invasive procedures, interpretation of laboratory results, and the human dilemmas produced by the demonstration of discordant abnormality. Recent applications of ultrasound, including Doppler ultrasound, are also discussed in the context of the monochorionic placenta, prediction of preterm labor, and detection of intrauterine growth retardation.