ABSTRACT
The increases in both the rate and the number of multiple births in the USA and Western Europe have been well documented in the literature. Several factors seem to be responsible for the rising incidence of multiple births, including the rapid growth in the use of assisted reproductive technologies (ART) and the rise in the average age of women giving birth to their first child (older mothers have a greater likelihood of spontaneous multiple pregnancies and at the same time a greater prevalence of ART procedures). 1
