The Essence of Tocolysis

Preterm birth, defined as birth before 37 weeks gestation, is a major contributor to perinatal morbidity and mortality. It occurs in 12,000 pregnancies in the Netherlands per year. Of all perinatal mortality, 50-70% can be attributed to preterm birth. Preterm birth can be iatrogenic due to the condition of the mother or the child, but the majority occurs spontaneously, either starting with preterm rupture of membranes (PROM) or with spontaneous contractions [1-3]. As such, spontaneous preterm birth is the leading cause of perinatal mortality and neonatal morbidity, mostly due to respiratory immaturity, intracranial hemorrhage and infections. These conditions can have long-term neuro developmental sequelae such as intellectual impairment, cerebral palsy, chronic lung disease, deafness and blindness. Death due to complications of prematurity is ranked 7th in the global deaths rank and together with communicable, maternal, and nutritional causes responsible for 25% of the deaths worldwide. Hence, spontaneous preterm birth is one of the largest single conditions in the Global Burden of Disease analysis given the high mortality and the considerable risk of lifelong impairment.