Reproductive, gynaecological and surgical history of all enrolled participants
| OP | TP | IUP | Crude OR1 (95% CI)* | Crude OR2 (95% CI)† | |||||
|---|---|---|---|---|---|---|---|---|---|
| n‡ | (%) | n‡ | (%) | n‡ | (%) | OP vs TP | OP vs IUP | p Value | |
| Reproductive history | |||||||||
| Number of previous abortions | 0.29 | ||||||||
| 0 | 37 | (52.86) | 52 | (36.88) | 64 | (43.84) | Ref | Ref | |
| 1 | 22 | (31.43) | 47 | (33.33) | 41 | (28.08) | 0.85 (0.43 to 1.67) | 0.89 (0.46 to 1.72) | |
| 2 | 8 | (11.43) | 31 | (21.99) | 26 | (17.81) | 0.37 (0.16 to 0.90) | 0.53 (0.22 to 1.30) | |
| ≥3 | 3 | (4.29) | 11 | (7.80) | 15 | (10.27) | 0.33 (0.09 to 1.23) | 0.35 (0.09 to 1.27) | |
| Parity | 0.28 | ||||||||
| 0 | 43 | (61.43) | 64 | (45.39) | 68 | (46.58) | Ref | Ref | |
| 1 | 26 | (37.14) | 69 | (48.94) | 71 | (48.63) | 0.62 (0.34 to 1.12) | 0.59 (0.33 to 1.07) | |
| ≥2 | 1 | (1.43) | 8 | (5.67) | 7 | (4.80) | 0.20 (0.02 to 1.65) | 0.23 (0.03 to 1.95) | |
| Gynaecological history | |||||||||
| Previous ectopic pregnancy | <0.01 | ||||||||
| No | 68 | (95.78) | 122 | (84.72) | 144 | (98.63) | Ref | Ref | |
| Yes | 3 | (4.23) | 22 | (15.28) | 2 | (1.37) | 0.24 (0.07 to 0.82) | 3.22 (0.52 to 19.45) | |
| Serum CT IgG test | <0.01 | ||||||||
| Negative | 57 | (85.08) | 95 | (65.97) | 128 | (90.14) | Ref | Ref | |
| Positive | 10 | (14.93) | 49 | (34.03) | 14 | (9.86) | 0.34 (0.16 to 0.72) | 1.60 (0.67 to 3.83) | |
| Previous infertility | 0.002 | ||||||||
| No | 55 | (84.62) | 111 | (76.55) | 137 | (94.48) | Ref | Ref | |
| Others | 1 | (1.54) | 6 | (4.14) | 3 | (2.07) | 0.34 (0.04 to 2.86) | 0.83 (0.09 to 8.16) | |
| Tubal infertility | 9 | (13.85) | 28 | (19.31) | 5 | (3.45) | 0.65 (0.29 to 1.47) | 4.48 (1.44 to 13.98) | |
| Mode of pregnancy | 0.67 | ||||||||
| Natural conception | 61 | (88.41) | 135 | (93.10) | 144 | (98.63) | Ref | Ref | |
| Other ART | 1 | (1.45) | 3 | (2.21) | 2 | (1.37) | 0.74 (0.08 to 7.24) | 1.18 (0.11 to 13.26) | |
| IVF-ET | 7 | (10.15) | 7 | (4.83) | 0 | (0.00) | 2.21 (0.74 to 6.59) | NA | |
| Previous caesarean section§ | 0.71 | ||||||||
| No | 16 | (59.26) | 38 | (50.00) | 41 | (52.56) | Ref | Ref | |
| Yes | 11 | (40.74) | 38 | (50.00) | 37 | (47.44) | 0.69 (0.28 to 1.67) | 0.76 (0.31 to 1.85) | |
| Previous adnexal surgery | <0.01 | ||||||||
| No | 64 | (91.43) | 109 | (75.17) | 141 | (96.58) | Ref | Ref | |
| Yes | 6 | (8.57) | 36 | (24.83) | 5 | (3.43) | 0.28 (0.11 to 0.71) | 2.64 (0.78 to 8.98) | |
| Previous appendectomy | 0.56 | ||||||||
| No | 65 | (94.20) | 138 | (97.18) | 140 | (96.55) | Ref | Ref | |
| Yes | 4 | (5.80) | 4 | (2.82) | 5 | (3.45) | 2.12 (0.52 to 8.76) | 1.72 (0.45 to 6.63) | |
| Current contraceptive experience | 0.06 | ||||||||
| None users | 42 | (60.00) | 86 | (59.31) | 101 | (74.27) | Ref | Ref | |
| Intrauterine device | 7 | (10.00) | 7 | (4.83) | 2 | (1.47) | 2.05 (0.67 to 6.22) | 8.42 (1.68 to 42.20) | |
| Oral contraceptive pills | 1 | (1.43) | 1 | (0.69) | 0 | (0.00) | 2.05 (0.13 to 33.55) | NA | |
| Female sterilisation | 0 | (0.00) | 2 | (1.38) | 0 | (0.00) | NA | NA | |
| Emergency contraceptive pills | 4 | (5.71) | 25 | (17.24) | 8 | (5.88) | 0.33 (0.11 to 1.03) | 1.20 (0.34 to 4.21) | |
| Other contraceptive methods¶ | 16 | (22.86) | 24 | (16.55) | 35 | (25.74) | 1.37 (0.66 to 2.84) | 1.10 (0.55 to 2.20) | |
*OR1 refers to the OR for OP when using TP patients as control.
†OR2 refers to the OR for OP when using IUP women as control.
‡The sum does not necessarily equal the sample size for all variables because of missing data.
§The number of women who had delivered a child was used as the denominator to calculate the percentage.
¶Other contraceptive methods included condoms, the rhythm method and withdrawal.
CT, Chlamydia trachomatis; IUP, intrauterine pregnancy; NA, not applicable; OP, ovarian pregnancy; Ref, reference; TP, tubal pregnancy.