In Table 2, the overall success rate of preterm uterine contraction inhibition for prolongation of pregnancy at least for 48 hours was 86.4%. The success rate among who were diagnosed as threatened preterm labor on admission was high (93.8%), while the success rate among who were diagnosed as preterm labor on admission was low (60.9%). High risk of preterm delivery group had high success rate (85.0%). The more cervical dilatation group had the more failure rate. Calcium channel blocker had the better effect than betamimetics and combination of tocolytics. More than 80% of included women received complete course of corticosteroid before delivery. Approximately half of the studied women (55.3%) had prolonged pregnancy beyond 34 weeks. One-third of them (38.8%) gave birth after 37 weeks of gestation.