Steps to Extend Latency in Preterm Prelabor Rupture of Membranes (STEP)

The primary objective of this study is to determine if there is increased latency to delivery for patients with PPROM who ambulate ≥3500 steps per day compared to those who ambulate less. The investigators have chosen a goal of 3500 steps as this equates to approximately 30 minutes of moderate-intensity walking, and ACOG endorses the US Department of Health and Human Services Physical Activity Guidelines which recommend at least 150 minutes of moderate intensity aerobic activity per week during pregnancy.

The secondary objective of this study is to determine whether there is a lower risk of adverse maternal and neonatal outcomes for patients with PPROM who ambulate ≥3500 steps per day compared to those who ambulate less. Maternal adverse outcomes that will be assessed include rate of intra-amniotic infection, placental abruption, umbilical cord prolapse, cesarean delivery for non-reassuring fetal heart tracing, and thromboembolic events. Neonatal adverse outcomes that will be assessed include gestational age at delivery, birth weight, APGAR score at 5 minutes, requirement for NICU admission, length of stay, and neonatal death. The investigators will also assess the average steps per day for each participant and type of smartphone (i.e. Android vs iPhone).

Inclusion criteria include patients admitted to Cedars-Sinai with PPROM between the gestational ages of 24w0d and 33w6d who have planned inpatient management of at least 7 days, a phone capable of monitoring and sharing step count, and a singleton or dichorionic twin gestation. Exclusion criteria include patients with malpresentation (specifically, transverse, footling breech, or funic presentation), active preterm labor, or active vaginal bleeding.

This is a quasi-experimental study. All patients will be encouraged to ambulate ≥3500 steps per day. Patients will then be categorized into two cohorts: those who ambulated ≥3500 steps per day and those who ambulated <3500 steps per day. Outcomes will be compared between the two cohorts.

The duration of the study for each patient is the length of time from admission to delivery.

The study will be conducted at one site only, Cedars-Sinai.

At the time of study recruitment, patients will be given information about exercise in pregnancy and encouraged to ambulate at least 3500 steps per day. They will also be asked to share their daily step count via their smartphone health app with a member of the research team. All other antepartum, intrapartum, and postpartum care will be standard and/or per the primary obstetrician's discretion. After hospital discharge, a member of the research team will record the patient's daily step count and extract demographic information as well as obstetric and neonatal outcomes from the EMR.

Our primary outcome is the mean number of days of latency to delivery, and the investigators will use a Welch's t-test to assess the difference between our two study groups. The investigators will then use a multivariable linear regression analysis to account for potentially confounding variables.

For our secondary outcomes, the investigators will assess time from diagnosis to delivery using a log-rank test followed by a cox regression analysis. Additionally, maternal demographic and obstetric outcomes as well as neonatal outcomes will be compared using chi square and t-test for categorical and continuous variables, respectively.