Influence of Gestational Age on the Time from Spontaneous Rupture of the Chorioamniotic Membranes to the Onset of Labor

David A. Savitz; Cande V. Ananth; Edwin R. Luther; John M. Thorp Jr

doi:10.1055/s-2007-994112

American Journal of Perinatology, Table of Contents

Am J Perinatol 1997; 14(3): 129-133
DOI: 10.1055/s-2007-994112

ORIGINAL ARTICLE

Influence of Gestational Age on the Time from Spontaneous Rupture of the Chorioamniotic Membranes to the Onset of Labor

David A. Savitz¹ , Cande V. Ananth¹ , Edwin R. Luther² , John M. Thorp, Jr.³

¹Carolina Population Center and Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill, North Carolina
²Department of Obstetrics and Gynecology, School of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
³Department of Obstetrics and Gynecology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina

Abstract

ABSTRACT

Our goal was to assess the influence of gestational age on the timing of labor onset following spontaneous rupture of the chorioamniotic membranes. The 24,831 patients in the Nova Scotia Atlee perinatal database from 1986 to 1992 whose membranes ruptured prior to labor onset and had live births were analyzed using life-table analysis methods. The probability of labor onset at specified intervals following rupture was markedly lower when rupture occurred earlier in gestation. Pregnancies of <33 weeks' gestation were less than half as likely as term pregnancies to proceed to labor within 24 hours and pregnancies of 33-36 weeks' gestation were 50-75% as likely as term pregnancies to progress within that period. These data provide clear evidence that the earlier in gestation the rupture occurs, the less likely labor onset is within specified time periods. This pattern supports the contention that preterm rupture of membranes is etiologically distinct from preterm labor.

Keywords

PROM - membrane rupture - preterm delivery

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