Table 1 Descriptive statistics of incident cervical insufficiency (ICI) cases and controls, stratified by parity
Nulliparous (N=11,087) | Parous (N=15,798) | |||||
|---|---|---|---|---|---|---|
CI (n=759) (%) | Control (n=10,328) (%) | Crude OR (95% CI) | CI (n=1498) (%) | Control (n=14,300) (%) | Crude ORa (95% CI) | |
Height (cm) | 165.4 ± 6.88 | 166.5 ± 6.36 | 0.97 (0.96, 0.99) | 165.2 ± 6.39 | 166.2 ± 6.27 | 0.98 (0.97, 0.99) |
Missing, N (%) | 107 (14.10) | 813 (7.87) | ~ | 146 (9.75) | 1065 (7.45) | ~ |
BMI | 24.68 ± 4.95 | 23.85 ± 4.26 | 1.05 (1.04, 1.07) | 24.75 ± 4.80 | 24.56 ± 4.38 | 1.01 (1.00, 1.02) |
Missing, N (%) | 148 (19.50) | 1412 (13.67) | ~ | 218 (14.55) | 1900 (13.29) | ~ |
Age (years) | 29.02 ± 5.08 | 27.38 ± 5.88 | 1.07 (1.06, 1.09) | 32.02 ± 5.06 | 30.96 ± 4.78 | 1.05 (1.04, 1.07) |
Mother’s country of birth: | ||||||
Sweden (reference) | 540 (71.15) | 8478 (82.09) | 1020 (68.09) | 11335 (79.27) | ||
African and Eastern Mediterranean | 97 (12.78) | 589 (5.70) | 2.79 (2.26, 3.44) | 171 (11.42) | 1116 (7.80) | 1.7 (1.45, 2.00) |
Other | 107 (14.10) | 1168 (11.31) | 1.7 (1.41, 2.04) | 295 (19.69) | 1782 (12.46) | 1.83 (1.60, 2.08) |
Previous miscarriage number: | ||||||
None | 397 (52.31) | 9068 (87.80) | 795 (53.07) | 10910 (76.29) | ||
1 | 177 (23.32) | 1081 (10.47) | 3.46 (2.92, 4.09) | 367 (24.50) | 2496 (17.45) | 2.05 (1.81, 2.32) |
2 | 126 (16.60) | 140 (1.36) | 16.16 (12.91, 20.22) | 182 (12.15) | 659 (4.61) | 3.66 (3.09, 4.32) |
≥3 | 59 (7.77) | 39 (0.38) | 27.31 (19.83, 37.60) | 154 (10.28) | 235 (1.64) | 9.63 (7.90, 11.74) |
Any miscarriage | 362 (47.69) | 1260 (12.20) | 6.21 (5.42, 7.12) | 703 (46.93) | 3390 (23.71) | 2.92 (2.64, 3.23) |
Multifetal gestation | 37 (4.87) | 85 (0.82) | 6.32 (4.74, 8.44) | 57 (3.81) | 211 (1.48) | 3.05 (2.35, 3.95) |
Smoking during pregnancy | 99 (13.04) | 1254 (12.14) | 1.12 (0.91, 1.37) | 222 (14.82) | 1752 (12.06) | 1.34 (1.15, 1.55) |
Missing | 248 (32.67) | 412 (27.39) | ~ | 458 (30.57) | 4050 (28.32) | ~ |
Chronic diabetes | 9 (1.19) | 51 (0.49) | 2.68 (1.46, 4.91) | 21 (1.40) | 93 (0.65) | 2.09 (1.32, 3.30) |
Polycystic ovarian syndrome | 14 (1.84) | 100 (0.97) | 3.38 (2.31, 4.94) | 20 (1.34) | 66 (0.46) | 2.89 (1.92, 4.34) |
History of dilation and curettage | 18 (2.37) | 138 (1.34) | 1.89 (1.22, 2.93) | 44 (2.94) | 162 (1.13) | 2.36 (1.70, 3.26) |
History of cervical excision | 47 (6.19) | 303 (2.93) | 2.22 (1.67, 2.95) | 103 (6.88) | 473 (3.31) | 2.25 (1.82, 2.77) |
History of any cervical procedures | 67 (8.83) | 487 (4.72) | 1.97 (1.55, 2.50) | 142 (9.48) | 736 (5.15) | 1.96 (1.64, 2.34) |
Parity more than two | ~ | ~ | ~ | 668 (44.59) | 5112 (33.75) | 1.38 (1.24, 1.53) |
Previous gestational diabetes | ~ | ~ | ~ | 20 (1.34) | 167 (1.17) | 1.64 (1.00, 2.68) |
Previous delivery with prolonged second stage of labor: | ||||||
None | 1141 (76.17) | 10,315 (72.13) | ||||
1 | ~ | ~ | ~ | 295 (19.69) | 3215 (22.48) | 0.83 (0.73, 0.95) |
2 or more | ~ | ~ | ~ | 62 (4.14) | 770 (5.38) | 0.73 (0.60, 0.88) |
Previous PPROM | ~ | ~ | ~ | 87 (5.81) | 295 (2.06) | 2.93 (2.29, 3.74) |
Previous Preterm birth | ~ | ~ | ~ | 301 (20.09) | 1216 (8.50) | 2.71 (2.35, 3.11) |
Total number of previous preterm births: | ||||||
None | 1197 (79.91) | 13,084 (91.50) | ||||
1 | ~ | ~ | ~ | 248 (16.56) | 1179 (8.24) | 2.3 (1.98, 2.67) |
2 or more | ~ | ~ | ~ | 53 (3.54) | 37 (0.26) | 15.66 (10.2, 23.9) |
Weeks to term of if premature delivery prior to index | ~ | ~ | ~ | 5.29 ± 4.37 | 2.91 ± 2.69 | 1.53 (1.48, 1.58) |
Number of previous cesarean: | ||||||
None | 1218 (81.31) | 11,892 (83.16) | ||||
1 | ~ | ~ | ~ | 262 (17.49) | 2289 (16.01) | 1.12 (0.97, 1.29) |
2 or more | ~ | ~ | ~ | 18 (1.20) | 119 (0.83) | 1.48 (0.90, 2.44) |
Previous macrosomia | ~ | ~ | ~ | 329 (21.96) | 4019 (28.10) | 0.72 (0.63, 0.82) |