Nifedipine Maintenance Tocolysis and Perinatal Outcome: An Individual Participant Data Meta-Analysis

( BJOG . 2016;123:1753–1760) Preterm birth (<37 wk of gestation) is the leading cause of neonatal mortality and morbidity in developed countries, accounting for 75% of perinatal deaths and more than 50% of childhood neurological disorders. In addition, the rate of preterm birth has been increasing.