From: Early-life exposures and age at thelarche in the Sister Study cohort
 | Age at thelarche | |||||
---|---|---|---|---|---|---|
Early (≤ 10 years) | Average (11–13 years) | Late (≥ 14 years) | ||||
n | % | n | % | n | % | |
Number of participants | 6613 | 13 | 34,030 | 69 | 8519 | 17 |
Participant characteristics | ||||||
Birth cohort | ||||||
 1928–1939 | 613 | 10 | 4220 | 72 | 1045 | 18 |
 1940–1949 | 2116 | 13 | 11,403 | 71 | 2607 | 16 |
 1950–1959 | 2469 | 14 | 12,619 | 69 | 3186 | 17 |
 1960–1974 | 1415 | 16 | 5788 | 65 | 1681 | 19 |
Race/ethnicity | ||||||
 Non-Hispanic White | 5275 | 13 | 29,141 | 70 | 7015 | 17 |
 Non-Hispanic African-American/Black | 754 | 18 | 2,517 | 61 | 835 | 20 |
 Hispanic/Latina | 422 | 18 | 1,525 | 65 | 399 | 17 |
 Othersa | 162 | 13 | 847 | 66 | 270 | 21 |
Family income level growing up | ||||||
 Well off | 436 | 14 | 2,194 | 70 | 507 | 16 |
 Middle income | 3863 | 13 | 20,597 | 70 | 4899 | 17 |
 Low income | 1739 | 14 | 8,693 | 68 | 2331 | 18 |
 Poor | 575 | 15 | 2,546 | 65 | 782 | 20 |
Maternal vital status at baseline | ||||||
 Alive | 3198 | 14 | 15,788 | 69 | 4040 | 18 |
 Deceased | 3408 | 13 | 18,196 | 70 | 4465 | 17 |
 Missing | 7 |  | 46 |  | 14 |  |
Maternal pregnancy characteristics | ||||||
Diabetes | ||||||
 Any (pre-pregnancy or gestational) | 77 | 17 | 307 | 67 | 74 | 16 |
 None | 5816 | 13 | 30,259 | 69 | 7519 | 17 |
 Missing | 720 |  | 3464 |  | 926 |  |
Gestational hypertensive disorder | ||||||
 Any (gestational hypertension or pre-eclampsia) | 285 | 17 | 1144 | 67 | 280 | 16 |
 None | 4708 | 13 | 24,505 | 69 | 6086 | 17 |
 Missing | 1620 |  | 8381 |  | 2153 |  |
DES use | ||||||
 Yes | 181 | 16 | 770 | 67 | 191 | 17 |
 No | 5399 | 13 | 28,273 | 70 | 6969 | 17 |
 Missing | 1033 |  | 4987 |  | 1359 |  |
Smoking during pregnancy | ||||||
 Yes | 2201 | 15 | 10,131 | 68 | 2546 | 17 |
 No | 4086 | 13 | 22,236 | 70 | 5553 | 17 |
 Missing | 326 |  | 1663 |  | 420 |  |
Farm exposure | ||||||
 Work and residence | 770 | 13 | 3977 | 69 | 983 | 17 |
 Work only | 88 | 14 | 409 | 65 | 130 | 21 |
 Residence only | 269 | 13 | 1458 | 71 | 313 | 15 |
 None | 5263 | 13 | 27,132 | 69 | 6774 | 17 |
 Missing | 223 |  | 1054 |  | 319 |  |
Age at delivery | ||||||
 < 20 years | 403 | 17 | 1544 | 66 | 387 | 17 |
 20–24 years | 1626 | 14 | 7916 | 69 | 1970 | 17 |
 25–29 years | 1904 | 13 | 10,189 | 69 | 2586 | 18 |
 30–34 years | 1419 | 13 | 7873 | 70 | 1916 | 17 |
 35–39 years | 854 | 13 | 4464 | 70 | 1096 | 17 |
 ≥ 40 years | 314 | 13 | 1672 | 69 | 444 | 18 |
 Missing | 93 |  | 372 |  | 120 |  |
Birth and infancy characteristics | ||||||
Firstborn | ||||||
 Yes | 1699 | 15 | 7931 | 70 | 1664 | 15 |
 No | 4877 | 13 | 25,915 | 69 | 6814 | 18 |
 Missing | 37 |  | 184 |  | 41 |  |
Birthweight | ||||||
 < 2500 g | 532 | 14 | 2505 | 67 | 692 | 19 |
 2500–3999 g | 4028 | 14 | 20,577 | 70 | 4900 | 17 |
 ≥ 4000 g | 452 | 14 | 2331 | 70 | 555 | 17 |
 Missing | 1601 |  | 8617 |  | 2372 |  |
Multiple birth | ||||||
 Yes | 182 | 12 | 1062 | 69 | 297 | 19 |
 No | 6430 | 14 | 32,963 | 69 | 8,221 | 17 |
 Missing | 1 |  | 5 |  | 1 |  |
Gestational age at birth | ||||||
 Born ≥ 1 month before due date | 126 | 13 | 672 | 68 | 192 | 19 |
 Born 2–4 weeks before due date | 279 | 15 | 1324 | 70 | 301 | 16 |
 Not born ≥ 2 weeks before due date | 2784 | 14 | 13,773 | 69 | 3383 | 17 |
 Missing | 3424 |  | 18,261 |  | 4643 |  |
Ever breastfed | ||||||
 Yes | 2993 | 13 | 15,608 | 70 | 3768 | 17 |
 No | 3147 | 14 | 15,923 | 69 | 4046 | 18 |
 Missing | 473 |  | 2499 |  | 705 |  |
Ever fed soy formula | ||||||
 Yes | 179 | 15 | 797 | 67 | 219 | 18 |
 No | 5261 | 13 | 27,471 | 69 | 6827 | 17 |
 Missing | 1173 |  | 5762 |  | 1473 |  |