Table 5.
Reproductive History in Female PBC Cases and Controls
| Cases (%) (n = 955) | Controls (%) (n = 959) | Unadjusted P Value | |
|---|---|---|---|
| Mean age at menarche | 12.6 ± 1.6 | 12.7 ± 1.8 | NS |
| Mean current duration of cycle (days) | 28.5 ± 5.6 | 28.0 ± 4.7 | .0191 |
| Mean current duration of period (days) | 5.1 ± 1.8 | 5.3 ± 2.4 | NS |
| Menopausal | 453 (47%) | 426 (45%) | NS |
| Mean age at last period | 46 ± 7 | 46 ± 7 | NS |
| Ever taken birth control pill | 725 (75%) | 681 (71%) | .0738 |
| Ever used hormone replacement | 587 (60%) | 473 (49%) | <.0001 |
| Currently on hormone replacement | 357 (62%) | 222 (47%) | <.0001 |
| Ever used IUD | 208 (22%) | 171 (17%) | .0337 |
| History of gynecological surgery | |||
| Hysterectomy | 303 (32%) | 292 (30%) | NS |
| Ovariectomy | 231 (24%) | 211 (22%) | NS |
| Pregnancy | |||
| None | 89 (9%) | 87 (9%) | 1 |
| Number of pregnancies | 3.1 ± 4.9 | 3.0 ± 3.1 | NS |
| Age at first pregnancy | 22.6 ± 5 | 23.3 ± 5 | .0105 |
| Conditions | |||
| Endometriosis | 133 (14%) | 119 (12%) | NS |
| Uterine fibrosis | 287 (30%) | 258 (27%) | .1162 |
| Pelvic inflammatory disease | 32 (3%) | 26 (3%) | NS |
| Vaginal infection | 604 (63%) | 539 (56%) | .0018 |
| Episode of vaginal infection/life | 11.0 ± 21.0 | 10.0 ± 22.0 | .0755 |
NOTE. Continuous variables are expressed as mean ± standard deviation.