Preterm prelabour rupture of the membranes (PPROM) is an important clinical problem and a dilemma for the gynaecologist. On the one hand, awaiting spontaneous labour may lead to an increase in infectious disease for both mother and child, whereas on the other hand induction of labour leads to preterm birth with an increase in neonatal morbidity (e.g., respiratory distress syndrome (RDS)) and a possible rise in the number of instrumental deliveries.
The estimated incidence of PPROM between 34 and 37 weeks of gestation is 1.5%, which equals about 3.000 cases per year in the Netherlands. The incidence of RDS is estimated to decrease from 15% at 34 weeks to below 1% at 37 weeks' gestation [1
]. On the other hand, the probability that sepsis occurs increases when expectant management is advocated. In case the child is born immediately after PPROM, the risk of sepsis is 2.5%, whereas it increases to 7.5% in case of expectant management [2
Until now, management of PPROM between 34 and 37 weeks' gestation varies in the Netherlands. In the guideline of the Dutch Society of Obstetrics and Gynaecology (NVOG) expectant management is advocated if the gestational age is under 35 weeks [4
]. Beyond 35 weeks, the guideline makes no clear recommendation, and the decision for either induction of labour or expectant management (either in hospital or with monitoring at home), is left to local protocols. International guidelines do not make a clear statement either [5
This dilemma can be explained by a lack of good clinical evidence. As a consequence, the course of action on this subject varies in the Netherlands. Data from the Dutch National Delivery Registration indicate that in about 70% of the patients an expectant management has been practised, whereas in about 30% of the cases labour was induced preterm. The current national registrations provide no insight in the reason for induction in the latter group, as some inductions might have been performed following signs of intra-uterine infection.
In view of the lack of good clinical evidence and the practice variation described above, a randomised clinical trial comparing induction of labour and expectant monitoring in patients with PPROM is needed urgently.
We are aware of four small studies that have been performed to discern between the treatment policies for PPROM [7
]. Naef et al. compared induction of labour versus expectant management in a group of 120 patients with PPROM occurring at 34 until 37 weeks gestation and found a non-significant decrease of chorioamnionitis in the induction group without a significant difference in neonatal morbidity (including RDS) between both groups [7
]. Patients with PPROM managed expectantly were hospitalised significantly longer. More babies of the expectant group were diagnosed with sepsis and admitted to the neonatal ward for a longer duration. This difference did not reach the level of significance due to the small number of the study.
Cox et al. compared maternal and neonatal outcome in a group of 129 patients with PPROM occurring at 30 until 34 weeks' gestation after randomization between expectant management and induction of labour [8
]. Again, no significant differences in neonatal outcome were noted. However, a non-significant decrease in sepsis was seen in the induction group. Also, chorioamnionitis was observed less frequently in the latter group. Mercer et al. performed a similar study of 93 patients with PPROM in a different age category (32 until 36 weeks' gestation) and observed similar differences as Cox and co-workers [9
Spinnato et al. found no difference in neonatal outcome between expected management and prompt delivery in 47 patients with premature rupture of membranes (before 36 weeks) with documented foetal pulmonary maturity [10
]. However, they demonstrated an increased risk of maternal infection when expectant management was applied.
These studies show a trend towards better neonatal outcome in the induction group, but in these small samples differences were not statistically significant. Even meta-analysis did not generate sufficient statistical power [11
]. In view of the practice variation described above and the lack of sound clinical evidence for this clinical dilemma, we have recently started a multicentre trial.