ABSTRACT
Changes in the epidemiology of multiple gestation inuence the decision of how and when to deliver twins. e dramatic increase in the frequency of multiple birth has aected preterm deliveries.1 e 2002 U.S. vital statistics show that the twin birth rate reached a remarkable 3.1% of all live births; a 65% increase over the past two decades and a 38% increase since 1990.2 In 2002, the incidence of triplets and higher-order multiples was 1.84 per 1000 live births compared with about 1:10,000 births aer spontaneous conceptions.2
