Maternal cardiac troponin I levels during normal labor and delivery

Byline: Stephan A. Shivvers, Frank H. Wians, Joseph H. Keffer, Susan M. Ramin Keywords: Pregnant women; myocardial injury; troponin I Abstract: Objective: Diagnosis of myocardial infarction in pregnant women on the basis of changes in biochemical markers is complicated by the release of some of these markers from noncardiac tissue sources. We compared troponin I levels with those of other markers in normal pregnant women. Study Design: In 51 healthy women at term in labor, cardiac troponin I, myoglobin, creatine kinase, and creatine kinase MB levels were determined at admission, during the second stage of labor, and within 30 minutes, 12 hours, and 24 hours after delivery. Results: Mean admission levels for all markers were below the upper limit of normal. Mean concentrations of myoglobin, creatine kinase, and creatine kinase MB mass were increased nearly twofold within 30 minutes after delivery. The highest level of troponin I (0.134 ng/mL) at all time points was below the cutoff value (0.15 ng/mL) for discriminating myocardial infarction. Conclusions: Because only troponin I levels remained undetectable during and after delivery, it is potentially the most useful biochemical marker for monitoring pregnant women for myocardial injury. (Am J Obstet Gynecol 1999;180:122-7.) Author Affiliation: Dallas, Texas From the Department of Obstetrics and Gynecology.sup.a and the Department of Pathology,.sup.b University of Texas Southwestern Medical Center Article History: Received 16 April 1998; Revised 30 June 1998; Accepted 14 July 1998 Article Note: (footnote) [star] Reprint requests: Stephan A. Shivvers, MD, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75235-9032., [star][star] 0002-9378/99 $8.00 + 0 6/1/93219