Characteristic* | No (%)/mean (SD) | No (%) of endometriosis cases (any type) | No (%) of external endometriosis cases | No (%) of adenomyosis cases |
Birth year | ||||
1933–1944 | 545 (16.0) | 20 (18.0) | 15 (16.5) | 5 (20.8) |
1945–1949 | 1034 (30.4) | 30 (27.0) | 24 (26.4) | 8 (33.3) |
1950–1954 | 988 (29.0) | 37 (33.3) | 32 (35.2) | 7 (29.2) |
1955–1959 | 655 (19.2) | 21 (18.9) | 17 (18.7) | 4 (16.7) |
1960–1972 | 184 (5.4) | 3 (2.7) | 3 (3.3) | 0 (0) |
Birth weight (kg) | ||||
<3.0 | 526 (15.4) | 23 (20.7) | 19 (20.9) | 4 (16.7) |
3.0–3.4 | 1267 (37.2) | 49 (44.1) | 42 (46.2) | 9 (37.5) |
3.5–3.9 | 1201 (35.3) | 30 (27.0) | 25 (27.5) | 7 (29.2) |
≥4.0 | 412 (12.1) | 9 (8.1) | 5 (5.5) | 4 (16.7) |
Gestational age (weeks) | ||||
<37 | 171 (5.3) | 5 (4.8) | 4 (4.7) | 1 (4.8) |
37–41 | 2625 (81.1) | 85 (81.7) | 70 (82.4) | 16 (76.2) |
≥42 | 441 (13.6) | 14 (13.5) | 11 (12.9) | 4 (19.1) |
Mother’s age (years) | ||||
<20 | 290 (8.5) | 12 (10.8) | 9 (9.9) | 3 (12.5) |
20–34 | 2855 (84.0) | 91 (82.0) | 75 (82.4) | 20 (83.3) |
≥35 | 253 (7.5) | 8 (7.2) | 7 (7.7) | 1 (4.2) |
Father’s age (years) | ||||
<25 | 765 (22.9) | 32 (28.8) | 23 (25.3) | 10 (41.7) |
25–35 | 1615 (48.4) | 56 (50.5) | 51 (56.0) | 7 (29.2) |
≥36 | 956 (28.7) | 23 (20.7) | 17 (18.7) | 7 (29.2) |
Family SEP | ||||
High | 1279 (37.6) | 45 (40.5) | 34 (37.4) | 12 (50.0) |
Intermediate | 825 (24.3) | 31 (27.9) | 27 (29.7) | 5 (20.8) |
Low | 1298 (38.2) | 35 (31.5) | 30 (33.0) | 7 (29.2) |
Endometriosis in mother | ||||
No | 3362 (98.9) | 107 (96.4) | 87 (95.6) | 24 (100) |
Yes | 36 (1.1) | 4 (3.6) | 4 (4.4) | 0 (0) |
Adult education | ||||
Elementary | 738 (21.9) | 22 (19.8) | 16 (17.6) | 6 (25.0) |
Shorter secondary | 1289 (38.2) | 46 (41.4) | 36 (39.6) | 12 (50.0) |
Longer secondary | 844 (25.0) | 27 (24.3) | 24 (26.4) | 5 (20.8) |
Tertiary | 506 (15.0) | 16 (14.4) | 15 (16.5) | 1 (4.2) |
Adult standardised income, fourths | ||||
First (lowest) | 839 (25.0) | 20 (18.0) | 17 (18.7) | 3 (12.5) |
Second | 840 (25.0) | 28 (25.2) | 24 (26.4) | 5 (20.8) |
Third | 840 (25.0) | 33 (29.7) | 25 (27.5) | 10 (41.7) |
Fourth (highest) | 830 (25.0) | 30 (27.0) | 25 (27.5) | 6 (25.0) |
Number of live births† | ||||
0 | 468 (13.7) | 47 (42.3) | 45 (49.5) | 2 (8.3) |
1 | 497 (14.6) | 21 (18.9) | 19 (20.9) | 3 (12.05) |
≥2 | 2441 (71.7) | 43 (38.7) | 27 (29.7) | 19 (79.2) |
Infertility† | ||||
No | 3272 (96.1) | 96 (86.5) | 77 (84.6) | 23 (95.8) |
Yes | 134 (3.9) | 15 (13.5) | 14 (15.4) | 1 (4.2) |
Age at first birth‡ (years) | 24.1 (5.1) | – | – | – |
Age at last birth‡ (years) | 29.3 (5.5) | – | – | – |
*All correlation coefficients between study covariates were ≤0.7, most of them were <0.2.
†Prior to the specific endometriosis diagnosis.
‡Available for a subset of parous women (n=2956).
SEP, socioeconomic position.