Table 1 Baseline characteristics of 78,028 WHI study participants by birth weight category
From: Associations between birthweight and preterm birth and the ages at menarche and menopause
| Â | Birth weight category | Â | ||||
|---|---|---|---|---|---|---|
< 6 lbs. N = 7,096 | 6 lbs.–7 lbs. 15 oz. N = 52,661 | 8 lbs.–9 lbs. 15 oz. N = 15,591 | ≥ 10 lbs. N = 2,680 | Pa | ||
Age at baseline (years) | 63.1 (7.5) | 63.3 (7.3) | 63.4 (7.3) | 65.0 (7.0) | < 0.0001 | |
Race | Â | Â | Â | Â | Â | |
| Â | Asian/Pacific Islander | 348 (5.0) | 1,349 (2.6) | 171 (1.1) | 21 (0.8) | < 0.0001 |
| Â | Black | 710 (10.3) | 3,930 (7.6) | 866 (5.7) | 161 (6.1) | |
| Â | White | 5,725 (83.0) | 45,682 (88.5) | 14,081 (91.9) | 2,409 (91.6) | |
| Â | Other/Unknown | 115 (1.7) | 674 (1.3) | 199 (1.3) | 39 (1.5) | |
Ethnicity | Â | Â | Â | Â | Â | |
| Â | Hispanic/Latinx | 363 (5.2) | 2,096 (4.0) | 509 (3.3) | 84 (3.2) | < 0.0001 |
| Â | Not Hispanic/Latinx | 6,620 (94.8) | 50,101 (96.0) | 14,976 (96.7) | 2,574 (96.8) | |
Region | Â | Â | Â | Â | Â | |
| Â | Northeast | 1,518 (21.4) | 11,977 (22.7) | 3,424 (22.0) | 572 (21.3) | <0.0001 |
| Â | South | 1,928 (27.2) | 13,452 (25.5) | 3,979 (25.5) | 692 (25.8) | |
| Â | Midwest | 1,516 (21.4) | 3,979 (25.5) | 3,638 (23.3) | 642 (24.0) | |
| Â | West | 2,134 (30.1) | 692 (25.8) | 4,550 (29.2) | 774 (28.9) | |
Education | Â | Â | Â | Â | Â | |
|  | ≤ High school diploma/GED | 1,642 (23.4) | 10,423 (19.9) | 2,981 (19.3) | 664 (25.1) | < 0.0001 |
| Â | School after high school | 2,687 (38.3) | 18,987 (36.3) | 5,748 (37.2) | 1,071 (40.4) | |
| Â | College degree or higher | 2,695 (38.4) | 22,875 (43.8) | 6,735 (43.6) | 916 (34.6) | |
Normalized Socioeconomic Status (NSES) | 75.3 (9.0) | 76.2 (8.4) | 76.4 (8.0) | 75.4 (8.3) | < 0.0001 | |
BMI at baseline (kg/m2) | 27.3 (6.0) | 27.0 (5.7) | 27.7 (6.1) | 28.6 (6.6) | < 0.0001 | |
Smoking status | Â | Â | Â | Â | Â | |
| Â | Never | 3,705 (53.0) | 26,268 (50.5) | 7,500 (48.7) | 1,304 (49.4) | < 0.0001 |
| Â | Past | 2,793 (40.0) | 22,517 (43.3) | 6,894 (44.8) | 1,163 (44.1) | |
| Â | Current | 493 (7.1) | 3,195 (6.1) | 1,003 (6.5) | 173 (6.6) | |
Alcohol Use | Â | Â | Â | Â | Â | |
| Â | Non-drinker | 933 (13.2) | 5,459 (10.4) | 1,513 (9.8) | 321 (12.1) | < 0.0001 |
| Â | Past drinker | 1,484 (21.1) | 9,418 (18.0) | 2,827 (18.3) | 551 (20.7) | |
| Â | Current drinker | 4,628 (65.7) | 37,466 (71.6) | 11,153 (72.0) | 1,787 (67.2) | |
Participant breastfed | Â | Â | Â | Â | Â | |
| Â | Yes | 3,832 (67.4) | 30,743 (72.7) | 10,177 (77.2) | 1,853 (82.3) | < 0.0001 |
| Â | No | 1,856 (32.6) | 11,551 (27.3) | 3,009 (22.8) | 400 (17.8) | |
Age at menarche (years) | Â | Â | Â | Â | Â | |
|  | ≤ 11 | 1,701 (24.1) | 11,538 (22.0) | 3,517 (22.6) | 637 (23.9) | < 0.0001 |
| Â | 12 | 1,816 (25.7) | 13,813 (26.3) | 4,029 (25.9) | 670 (25.1) | |
| Â | 13 | 1,916 (27.1) | 15,466 (29.5) | 4,526 (29.1) | 713 (26.7) | |
| Â | 14 | 1,635 (23.1) | 11,628 (22.2) | 3,469 (22.3) | 646 (24.2) | |
Age at first regular period (years) | Â | Â | Â | Â | Â | |
|  | ≤ 11 | 908 (15.4) | 6,034 (13.7) | 1,920 (14.7) | 351 (16.1) | < 0.0001 |
| Â | 12 | 1,242 (21.1) | 9,125 (20.7) | 2,719 (20.8) | 444 (20.3) | |
| Â | 13 | 1,405 (23.8) | 11,598 (26.3) | 3,395 (25.9) | 555 (25.4) | |
| Â | >= 14 | 2,343 (39.7) | 17,351 (39.3) | 5,063 (38.7) | 836 (38.2) | |
Reproductive window (years) | 36.1 (6.4) | 36.6 (5.9) | 36.6 (5.9) | 36.1 (6.4) | < 0.0001 | |
Age at last regular period (years) | 46.9 (6.9) | 47.5 (6.6) | 47.5 (6.6) | 47.4 (6.8) | < 0.0001 | |
Age at last vaginal bleeding (years) | 47.8 (7.5) | 48.5 (7.3) | 48.5 (7.3) | 48.3 (7.4) | < 0.0001 | |
Age at natural menopause (years) | 48.6 (6.2) | 49.1 (5.8) | 49.2 (5.8) | 48.8 (6.2) | < 0.0001 | |
Were periods regular | Â | Â | Â | Â | Â | |
| Â | Yes | 5,663 (80.4) | 43,395 (82.9) | 12,736 (82.3) | 2,139 (80.5) | < 0.0001 |
| Â | No | 1,384 (19.6) | 8,978 (17.1) | 2,743 (17.7) | 519 (19.5) | |
Ever had a hysterectomy | Â | Â | Â | Â | Â | |
| Â | Yes | 3,117 (44.0) | 21,545 (41.0) | 6,521 (41.9) | 1,240 (46.3) | < 0.0001 |
| Â | No | 3,974 (56.0) | 31,068 (56.0) | 9,054 (58.1) | 1,438 (53.7) | |
Ever had an oophorectomy | Â | Â | Â | Â | Â | |
| Â | Yes | 2,200 (31.5) | 14,921 (28.7) | 4,528 (29.4) | 848 (32.2) | < 0.0001 |
| Â | No | 4,791 (68.5) | 37,057 (71.3) | 10,889 (70.6) | 1,788 (67.8) | |
Ever had premenopausal hot flashes | Â | Â | Â | Â | Â | |
| Â | Yes | 5,857 (82.6) | 43,902 (83.4) | 13,064 (83.9) | 2,242 (83.8) | 0.10 |
| Â | No | 1,236 (17.4) | 8,717 (16.6) | 2,511 (16.1) | 435 (16.3) | |
Ever had postmenopausal hot flashes | Â | Â | Â | Â | Â | |
| Â | Yes | 2,355 (49.4) | 17,531 (49.4) | 5,171 (49.1) | 882 (48.0) | 0.61 |
| Â | No | 2,417 (50.7) | 17,928 (50.6) | 5,366 (50.9) | 957 (52.0) | |