Table 3.
Characteristics at blood collection (1996-1999) of uterine fibroids 56 cases and 497 controls in the Nurses’ Health Study II, 1996-2009
| Controls | Cases | |||
|---|---|---|---|---|
| (n=497) | (n=56) | |||
| Age at blood draw (range), Mean (standard deviation [SD]) | 43 (33-52) | (4.0) | 43 (33-50) | (3.5) |
| Caucasian, n (%) | 471 | (94.8) | 54 | (96.4) |
| Parity, n (%) | ||||
| Nulliparous | 97 | (19.5) | 8 | (14.3) |
| 1 | 65 | (13.1) | 5 | (8.9) |
| 2 | 177 | (35.5) | 20 | (35.7) |
| 3 | 113 | (22.7) | 18 | (32.1) |
| 4+ | 45 | (9.0) | 5 | (8.9) |
| Age at first birth, n (%) | ||||
| <25 | 141 | (35.3) | 13 | (27.1) |
| 25-30 | 187 | (46.8) | 31 | (64.6) |
| 31+ | 72 | (18.0) | 4 | (8.3) |
| Time since last birth, n (%) | ||||
| <6 years | 102 | (25.5) | 14 | (29.2) |
| 6-12 years | 181 | (45.3) | 18 | (37.5) |
| 13+ years | 117 | (29.3) | 16 | (33.3) |
| Aqe at menarche, n (%) | ||||
| <12 | 96 | (19.3) | 12 | (21.4) |
| 12-13 | 315 | (63.3) | 35 | (62.5) |
| 14+ | 86 | (17.3) | 9 | (16.1) |
| Menstrual cycle length, n (%) | ||||
| <26 days | 93 | (19.2) | 9 | (17.0) |
| 26-31 days | 348 | (71.9) | 35 | (66.0) |
| 32+ days | 43 | (8.9) | 9 | (17.0) |
| Body mass index (kq/m2), Mean (SD) | 25.2 | (6.0) | 26.2 | (6.4) |