From: Risk factors for ectopic pregnancy: a multi-center case-control study
 | EP | IUP | OR [95 % CI] | p value | ||
---|---|---|---|---|---|---|
n a | (%) | n a | (%) | |||
Previous use of contraceptives | ||||||
 LNG-EC | ||||||
  No | 1283 | (53.57) | 1311 | (54.74) | Reference | 0.53 |
  Yes | 1112 | (46.43) | 1084 | (45.26) | 1.05 [0.94, 1.17] | |
 IUDs | ||||||
  No | 1993 | (83.74) | 2106 | (88.27) | Reference | <10−3 |
  Yes | 387 | (16.26) | 280 | (11.74) | 1.48 [1.25, 1.74] | |
 OCPs | ||||||
  No | 2254 | (94.47) | 2295 | (95.55) | Reference | 0.06 |
  Yes | 132 | (5.53) | 107 | (4.45) | 1.25 [0.97, 1.63] | |
 Other contraceptive methodsb | ||||||
  No | 829 | (35.32) | 421 | (17.50) | Reference | <10−3 |
  Yes | 1518 | (64.68) | 1985 | (82.50) | 0.39 [0.34, 0.45] | |
Current contraceptive methods | ||||||
 No | 1337 | (55.87) | 1585 | (65.60) | Reference | <10−3 |
 Other contraceptive methodsb | 447 | (18.68) | 653 | (27.03) | 0.81 [0.71, 0.93] | |
 OCPs | 16 | (0.67) | 7 | (0.29) | 2.71 [1.11, 6.61] | |
 LNG-EC | 341 | (14.25) | 145 | (6.00) | 2.79 [2.27, 3.43] | |
 IUDs | 231 | (9.65) | 24 | (0.99) | 11.41 [7.45, 17.48] | |
 Female sterilizationc | 21 | (0.88) | 2 | (0.08) | 12.45 [2.91, 53.18] |