The modern era of infertility treatment was heralded over half a century ago with the introduction of new hormonal drugs that could effectively induce ovarian ovulation. However, it was quickly recognized that the birth of these new "miracle drugs" was associated with a remarkable increase in the incidence of high-order multiple births. Despite the fantastic improvement in our ability to monitor ovarian response during ovulation induction, and our power to control the number of embryos introduced into the womb through IVF, multiple births remain a leading cause of long-term child morbidity among infertility patients. Efforts to prevent what was coined in the 1960s as the "multiple birth epidemic" remain an urgent concern. A new body of research clearly points at our capacity to reduce the risk of multiple births and their associated long term morbidity without diminishing current high success rates of infertility treatment.
Keywords: Assisted reproductive technology; Elective single embryo transfer; Gonadotropins; Ovulation induction; Perinatal outcome.