A study of risk factors for ruptured tubal ectopic pregnancy

Ruptured ectopic pregnancy is a leading cause of maternal mortality in the United States. The purpose of this study was to identify predictors of tubal rupture. A retrospective chart review of 236 ectopic pregnancies 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 parameters: age, gravida, parity, aborta, gestational age, preoperative and postoperative hemoglobin level, need for blood transfusion, serum human chorionic gonadotropin (hCG) levels, and findings on ultrasonogram and at surgery. We also compared the two groups in multiple risk factors for ectopic pregnancy. We used the generalized estimating equation (GEE) 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 with those under 100 mIU/ml. There was no significant difference between the two groups in gestational age, serum hCG levels, or ultrasound findings 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 significant decrease in the rupture rate over time (p = 0.34). There was an increased morbidity associated with tubal rupture. Tubal rupture cannot be predicted on the basis of any known risk factor, ultrasonogram findings, or serum hCG levels. Early diagnosis and treatment of ectopic pregnancy are the only modality available to prevent tubal rupture and its associated morbidity.