Timing of Clinical Interventions on the Last Trimester Pregnancy Complicated with Premature Rupture of Membranes

Objective To explore the optimal time for clinical interventions on third trimester pregnant women with premature rupture of membranes( PROM). Methods A retrospective study was conducted on clinical data of 604 healthy,at the last trimester( gestational age ≥34 weeks),and singleton pregnant women with PROM,who admitted to the hospital from January l,2010 to December 31,2011. All subjects were divided into 4 groups: women in group 1 were those fell into spontaneous labor within 12h after PROM( n = 169, 27. 9%); women in group 2 were in spontaneous labor between 12h to 24h after PROM( n = 136,22. 5%); group 3 included those women who were not in labor within 12h after PROM and oxytocin induction was offered( n = 124,20. 5%); women in group 4 oxytocin were administered for induction for women not in labor at 12h to 24h and those women who were not in labor over 24h after PROM,and oxytocin induction was offered after PROM( n = 175,28. 9%); the maternal and neonatal complications and outcomes of all pregnancies were reviewed and compared. Results Among the 604 cases,305( 50. 1%) fell into spontaneous labor,including 169( 28. 0%) within 12h with a cesarean section rate of 19. 5%( 33 /169),136( 22. 5%) at 12 ~ 24 h after PROM with the CSR of 22. 8%( 31 /136) and 175 did not go into labor spontaneously with a CSR of 69. 7%( 122 /175).( 2) Among the 604 women,299 were induced at 12h and 24h after PROM. The CSR,incidence of intrauterine infection,puerperal morbidity and perinatal mortality rate in group 3 were significantly lower than those of group 4[CSR: 50. 7%( 63 /124) vs 69. 7%( 122 /175); intrauterine infection: 6. 5%( 8 /124) vs 22. 7%( 40 /175); prerperal morbidity: 6. 5%( 8 /124) vs 19. 8%( 35 /175); perinatal mortality: 0. 5%( 1 /124) vs 4. 0%( 7 /175),P 0. 01],but no difference was found in the incidence of postpartum hemorrhage [1. 0%( 1 /98) vs 4. 0%( 7 /177),P 0. 05]. Conclusion Intervention is not recommended within 12h after PROM in the last trimester. However,induction of labor should be offered thereafter. However,the CSR and incidence of maternal and neonatal complications rise up if induction of labor postpones to 24h after PROM.