Ruptured ectopic pregnancy is a leading cause of maternal mortality in
the United States. The purpose of this study was to identify predicto
rs of tubal rupture. A retrospective chart review of 236 ectopic pregn
ancies in 215 patients treated at the Cleveland Clinic Foundation from
1983 through 1996 was performed. Patients were stratified by rupture
status of the ectopic pregnancy and compared for the following paramet
ers: age, gravida, parity, aborta, gestational age, preoperative and p
ostoperative hemoglobin level, need for blood transfusion, serum human
chorionic gonadotropin (hCG) levels, and findings on ultrasonogram an
d at surgery. We also compared the two groups in multiple risk factors
for ectopic pregnancy. We used the generalized estimating equation (G
EE) methodology and unbalanced repeated measures analysis of variance
to compare the two groups. Tubal rupture was found in 26.3% of ectopic
pregnancies. Tubal rupture occurred with any serum hCG level, even wi
th those under 100 mIU/ml. There was no significant difference between
the two groups in gestational age, serum hCG levels, or ultrasound fi
ndings except that the frequency of ruptured pregnancies increases as
the fluid amount documented on ultrasonography increases (p < 0.001).
There was no association between any of the risk factors or the number
of risk factors and frequency of tubal rupture. There was no signific
ant decrease in the rupture rate over time (p = 0.34). There was an in
creased morbidity associated with tubal rupture. Tubal rupture cannot
be predicted on the basis of any known risk factor, ultrasonogram find
ings, or serum hCG levels. Early diagnosis and treatment of ectopic pr
egnancy are the only modality available to prevent tubal rupture and i
ts associated morbidity.