Guidelines of rpm

ACOG PRACTICE BULLETIN
CLINICAL MANAGEMENT GUIDELINES FOR OBSTETRICIAN–GYNECOLOGISTS NUMBER 80, APRIL 2007
(Replaces Practice Bulletin Number 1, June 1998)

This Practice Bulletin was developed by the ACOG Committee on Practice Bulletins— Obstetrics with the assistance of Brian Mercer, MD. The information is designed to aid practitioners in making decisions about appropriate obstetric andgynecologic care. These guidelines should not be construed as dictating an exclusive course of treatment or procedure. Variations in practice may be warranted based on the needs of the individual patient, resources, and limitations unique to the institution or type of practice.

Premature Rupture of Membranes
Preterm delivery occurs in approximately 12% of all births in the United States and is amajor factor contributing to perinatal morbidity and mortality (1, 2). Despite extensive research in this area, the rate of preterm birth has increased by 38% since 1981 (3). Premature rupture of membranes (PROM) is a complication in approximately one third of preterm births. It typically is associated with brief latency between membrane rupture and delivery, increased potential for perinatalinfection, and in utero umbilical cord compression. Because of this, both PROM at and before term can lead to significant perinatal morbidity and mortality. There is some controversy over the optimal approaches to clinical assessment and treatment of women with term and preterm PROM. Management hinges on knowledge of gestational age and evaluation of the relative risks of preterm birth versusintrauterine infection, abruptio placentae, and cord accident that could occur with expectant management. The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research. Additional guidelines on the basis of consensus and expert opinion also are presented.

BackgroundThe definition of PROM is rupture of membranes before the onset of labor. Membrane rupture that occurs before 37 weeks of gestation is referred to as preterm PROM. Although term PROM results from the normal physiologic process of progressive membrane weakening, preterm PROM can result from a wide array of pathologic mechanisms acting individually or in concert (4). The gestational age and fetalstatus at membrane rupture have significant implications in the etiology and consequences of PROM. Management may be dictat-

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ed by the presence of overt intrauterine infection, advanced labor, or fetal compromise. When such factors are not present, especially with preterm PROM, obstetric management may have a significant impact onmaternal and infant outcomes. An accurate assessment of gestational age and knowledge of the maternal, fetal, and neonatal risks are essential to appropriate evaluation, counseling, and care of patients with PROM.

half of women with PROM who were managed expectantly gave birth within 5 hours, and 95% gave birth within 28 hours of membrane rupture (25). The most significant maternal risk of termPROM is intrauterine infection, a risk that increases with the duration of membrane rupture (25–29). Fetal risks associated with term PROM include umbilical cord compression and ascending infection.

Etiology
Membrane rupture may occur for a variety of reasons. At term, weakening of the membranes may result from physiologic changes combined with shearing forces created by uterine contractions(5–8). Intraamniotic infection has been shown to be commonly associated with preterm PROM, especially if preterm PROM occurs at earlier gestational ages (9). In addition, factors such as low socioeconomic status, second- and third-trimester bleeding, low body mass index (calculated as weight in kilograms divided by the square of height in meters) less than 19.8, nutritional deficiencies of...