ABSTRACT
Advances in assisted reproductive technologies and delay in childbearing have led to a considerable increase in the frequency of multiple gestations (1,2). The latter finding is due to the fact that twinning and multiple gestations increase with maternal age in spontaneous pregnancies. Many of these women are at increased risk for fetal chromosome abnormalities because of maternal age. Increased screening for a wide variety of Mendelian disorders has also led to more counseling and consideration of invasive prenatal diagnosis for women carrying singleton and multiple gestations.
