Objective: To assess the influencing factors of ectopic pregnancy (EP) in intrauterine device (IUD) users for promoting the safe use of IUD. Methods: 29 EP cases were collected and 1:1 matched controls in IUD users by case-control study. Results: The data showed that pregnancies had significant association with EP, two pregnancies and three or more pregnancies were increased the risk of EP, adjusted odds ratio [AOR]=14.39, 95% CI: 2.37, 87.49 and AOR=14.87, 95% CI: 2.27, 97.38, respectively. The risk of EP in women of previous abdominal or pelvic surgery was also significantly increased (AOR=4.43, 95% CI: 1.04, 18.92). While no significant association have been seen with age, first or second time use IUD, periods of insertion, types of IUD, and copper surface area of IUD. Conclusion: The results suggested that the number of pregnancies significantly increased the risk of EP; there was no significant association between the risk of EP and copper surface area and shape of IUD used. Therefore, it is beneficial to reduce the risk of EP by the prevention of unwilling pregnancy and induced abortion.
Jian Zhou, Yue-Hua Yang, Zhi-Ming Sun, Ying Li