Intermittent weekly contraction monitoring to predict preterm labor in low-risk women: a blinded study.
To assess the predictive value of uterine activity as a marker for subsequent preterm labor, 139 black, inner city women were monitored at least three times for 1 hour between 28-32 weeks' gestation using a portable tocodynamometer. All had singleton gestations and gave no previous history of preterm labor or delivery. They were monitored between 8 and 10 AM while sitting in the clinic waiting area. Uterine activity records, numbered randomly, were transmitted by telephone to a site remote from the hospital. No one having any clinical contact with the participants saw or received feedback regarding the contraction data. Tocodynamometry records were then mailed to another center where they were read by one investigator blinded to all clinical information. The mean contraction frequency during the single hour of weekly testing was significantly greater for the 16 women who developed preterm labor than for women who delivered at term at each point between weeks 28-32. Using greater than six contractions per hour on at least one occasion between 28-32 weeks' gestation as a predictor would have identified 12 of 16 women (sensitivity 75%) who subsequently developed preterm labor. This contraction frequency was noted in 26 of 123 women (21%) who labored at term (specificity 79%; P = .0003).
Main
D M
DM
Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia.
Katz
M
M
Chiu
G
G
Campion
S
S
Gabbe
S G
SG
D005260:Female; D006801:Humans; D008991:Monitoring, Physiologic; D007752:Obstetric Labor, Premature / Q000175:diagnosis* / Q000503:physiopathology / Q000517:prevention & control; D011237:Predictive Value of Tests; D011247:Pregnancy; D012307:Risk Factors; D014590:Uterine Contraction