Risk factors for ectopic pregnancy in women with symptomatic first-trimester pregnancies

Objective: To evaluate the association between ectopic pregnancy (EP), and clinical and historical factors among women presenting with pain and/or bleeding in early pregnancy. Design: Nested case-control study. Setting: University-medical center. Patient(s): Women with symptomatic early pregnancies of unknown location presenting for care between January 1, 1990 and July 31, 1999. Intervention(s): None. Main Outcome Measure(s): Clinical and historical risk factors were compared between women with EP and women with ongoing intrauterine pregnancies or spontaneous abortions. Result(s): The following factors were associated with, increased, risk, of EP: prior EP (odds ratio, 2.95 [95% confidence interval, 1.88'-4.73] for one prior EP and 16.04 [5.39- 47.72] for 2 or more), pelvic inflammatory disease history (1.5,[1.11-2.05]), pain at presentation (1.42 1.06-1.92]), vaginal bleeding at presentation (1.42[1.04-1.93]), and hCG of 501-2,000 mIU/mL (1.73[1.24-2.42]). Age younger than 25 years (0.59[0.41-0.85]) and a history of abortion were protective from EP (0.58[0.38-0.90]). Prior nontubal pelvic surgery, past intrauterine device use, prior cesarean section, and, current cervical infection demonstrated no association with EP. Conclusion(s): Evaluation of women with, a, symptomatic early pregnancy confirms, and refutes some,of, the classical risk factors for EP. Prior EP is a strong risk factor whereas pelvic inflammatory disease has an unexpected, weak, association. Previous abortion was found, to have a negative association, whereas nontubal surgery, cesarean, section, and a history of or concomitant cervical infection, have no association. Knowledge of all historical and clinical, factors,associated with EP may aid in early diagnosis.