Bed Rest After Preterm Premature Rupture of the Membranes

A Pilot Randomized Controlled Trial On Complete Bed Rest Versus Activity Restriction After Preterm Premature Rupture of the Membranes

Antepartum bed rest is widely prescribed after preterm premature rupture of the membranes (PPROM), although its effectiveness to prevent preterm birth has not been demonstrated. This pilot randomized controled trial (RCT) aims to access the impact of bed rest in maternal and neonatal outcomes in pregnancies complicated by premature rupture of the membranes.

Aims - To access the impact of bed rest in latency time to delivery, chorioamnionitis incidence and other maternal and neonatal outcomes in pregnancies complicated by PPROM, thus enabling proper sample size calculation for future powered RCT. Study population and Sample size - Eligible patients included those with single pregnancies with PPROM at 24+0-33+6 weeks of gestation who were admitted to and delivering at our tertiary center. PPROM was diagnosed on the basis of patient's history and sterile speculum examination with visualization of amniotic fluid pooling in the vagina and/or leaking from the cervical canal. Exclusion criteria included indication for immediate delivery on admission (chorioamnionitis, placenta abruption, cord prolapse, signs of fetal hypoxia/distress), fetal malformations, multiple gestation, and maternal immunosuppressive disease. Considering future sample size calculation based upon assumed differences between groups regarding latency and infection, we aimed a sample of 30 participants. Randomization - A pilot unblinded randomized controlled trial (RCT) in a 1:1 allocation ratio between two groups (complete bed rest versus activity restriction after PPROM). Simple random allocation sequence was generated by the investigators and implemented by sequentially numbered sealed envelopes. Participants were enrolled by physicians after hospital admission and written informed consent was obtained before randomization. The trial was conducted in a single tertiary center of the Portuguese national health system after approval by its ethical committee. Statistical analysis - An intention-to-treat analysis was performed with a significance level of 5%.

Participants on complete bed rest group kept antepartum confinement to bed with toileting restricted to bedpan use. Participants in this group received prophylactic subcutaneous enoxaparin (40mg/day).

Activity restriction group had motion limited to bathroom privileges and walks to the ward canteen four times per day.

Patients in this group received standard care for PPROM according to the institution protocol, including antepartum confinement to bed.

Patients in this group received standard care for PPROM according to the institution protocol but to had bathroom privileges and walks to the ward canteen four times per day.

Incidence of clinical chorioamnionitis (defined as maternal fever plus leukocytosis and CRP elevation, or as maternal fever plus any two of the following: fetal tachycardia; maternal tachycardia; uterine tenderness; purulent amniotic fluid)

Inclusion Criteria: single pregnancies AND PPROM at 24+0-33+6 weeks of gestation AND admitted to our tertiary center. Exclusion Criteria: indication for immediate delivery on admission (chorioamnionitis, placenta abruption, cord prolapse, signs of fetal hypoxia/distress) fetal malformations multiple gestation maternal immunosuppressive disease