Table 1.

Descriptive characteristics by reproductive status category of the female LSS and AHS cohorts with radiation dose, who were not diagnosed by death certificate or autopsy, and who were not pregnant ATB (n = 60,978)

CharacteristicReproductive status ATB
Premenarche (n = 9,128)Between menarche and first birth (n = 7,149)Post first birth (n = 13,836)Missing (n = 30,865)
n (%)n (%)n (%)n (%)
Age ATB (y)
    0-96,277 (68.7%)— (0.0%)— (0.0%)5,177 (16.8%)
    10-192,850 (31.2%)3,945 (55.2%)94 (0.7%)5,722 (18.9%)
    20-29(0.0%)2,564 (35.9%)3,575 (25.8%)4,072 (13.2%)
    30-39— (0.0%)467 (6.5%)5,179 (37.4%)4,385 (14.2%)
    40-49— (0.0%)173 (2.4%)3,677 (26.6%)5,202 (16.9%)
    ≥50— (0.0%)— (0.0%)1,311 (9.5%)6,307 (20.4%)
City
    Hiroshima6,652 (72.9%)5,257 (73.5%)11,163 (80.7%)19,656 (63.7%)
    Nagasaki2,476 (27.1%)1,892 (26.5%)2,673 (19.3%)11,209 (36.3%)
Distance from hypocenter (meters)
    NIC1,462 (16.0%)1,326 (18.6%)2,797 (20.2%)8,939 (29.0%)
    ≥3,0001,921 (21.1%)1,634 (22.9%)2,963 (21.4%)6,885 (22.3%)
    <3,0005,745 (62.9%)4,189 (58.6%)8,076 (58.4%)15,041 (48.7%)
Breast dose (Gy)
    <0.054,090 (44.8%)3,663 (51.2%)7,077 (51.2%)19,524 (63.3%)
    0.05-0.494,420 (48.4%)2,800 (39.2%)5,855 (42.3%)9,765 (31.6%)
    0.50-0.99348 (3.8%)354 (5.0%)541 (3.9%)903 (2.9%)
    1.00-1.99193 (2.1%)239 (3.3%)238 (1.7%)443 (1.4%)
    ≥2.077 (0.8%)93 (1.3%)125 (0.9%)230 (0.8%)
Age at menarche (y)
    >161,365 (13.9%)849 (10.8%)2,823 (23.9%)571 (27.2%)
    15-162,980 (30.4%)2,788 (35.6%)5,326 (45.1%)876 (41.7%)
    13-144,576 (46.7%)3,603 (46.0%)3,339 (28.3%)587 (28.0%)
    ≤12886 (9.0%)599 (7.6%)317 (2.7%)66 (3.1%)
    Missing— (0.0%)413 (5.0%)3,472 (22.7%)28,765 (94.3%)
Age at first birth (y)*
    <20393 (5.1%)358 (5.9%)3,022 (22.0%)187 (5.1%)
    20-244,161 (53.7%)3,009 (50.0%)8,271 (60.1%)1,652 (44.9%)
    25-292,717 (35.0%)1,869 (31.0%)1,983 (14.4%)1,453 (39.5%)
    ≥30485 (6.3%)786 (13.1%)477 (3.5%)384 (10.5%)
No. of births
    Nulliparous38 (0.5%)326 (5.2%)— (0.0%)415 (7.0%)
    1-25,658 (73.5%)3,726 (59.6%)3,335 (25.2%)3,024 (50.7%)
    3-41,891 (24.6%)1,937 (31.0%)4,982 (37.7%)1,815 (30.4%)
    >4112 (1.5%)267 (4.3%)4,896 (37.1%)709 (11.9%)
    Missing1,429 (15.7%)893 (12.5%)623 (4.5%)24,902 (80.7%)

NOTE: Percentages shown for missing data for a given variable are based on the total number of people in that category, whereas those shown for nonmissing values are based only on those with known data.

  • *Among parous women.