OBJECTIVE: Diagnosis of myocardial infarction in pregnant women on the basi
s of changes in biochemical markers is complicated by the release of some o
f these markers from noncardiac tissue sources. We compared troponin I leve
ls with those of other markers in normal pregnant women.
STUDY DESIGN: In 51 healthy women at term in labor, cardiac troponin I, myo
globin, creatine kinase, and creatine kinase MB levels were determined at a
dmission, 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 o
f normal. Mean concentrations of myoglobin, creatine kinase, and creatine k
inase MB mass were increased nearly twofold within 30 minutes after deliver
y. The highest level of troponin I (0.134 ng/mL) at all time points was bel
ow the cutoff Value (0.15 ng/mL) for discriminating myocardial infarction.
CONCLUSIONS: Because only troponin I levels remained undetectable during an
d after delivery, it is potentially the most useful biochemical marker for
monitoring pregnant women for myocardial injury.