Table 2. Descriptive statistics for early life variables.
| All cohort | Natural menopause | Early menopause (<45 years) | |||||
|---|---|---|---|---|---|---|---|
| Age of menarche | n | 250,143 | 111,034 | 11,565 | |||
| mean | 13.0 | 13.0 | 12.9 | ||||
| s.d. | 1.6 | 1.6 | 1.7 | ||||
| median (range) | 13 (5,25) | 13 (5,25) | 13 (5,21) | ||||
| Birth weight (kg) | n | 164,448 | 69,367 | 7,210 | |||
| mean | 3.2 | 3.2 | 3.2 | ||||
| s.d. | 0.6 | 0.6 | 0.7 | ||||
| median (range) | 3.2 (0.4,9) | 3.2 (0.4,9) | 3.2 (0.7,6.3) | ||||
| Year of birth | n | 257,516 | 113,417 | 11,794 | |||
| mean | 1951.5 | 1948.4 | 1949.6 | ||||
| s.d. | 8.0 | 5.6 | 7.1 | ||||
| median (range) | 1950 (1936,1970) | 1948 (1936,1969) | 1948 (1936,1969) | ||||
| n | % | n | % | n | % | ||
| Breastfed as a baby | No | 64,388 | 31.0 | 23,563 | 26.1 | 2,807 | 30.1 |
| Yes | 143,195 | 69.0 | 66,689 | 73.9 | 6,531 | 69.9 | |
| Total | 207,583 | 90,252 | 9,338 | ||||
| Comparative height at age 10 | Shorter | 53,619 | 21.2 | 23,549 | 21.1 | 2,502 | 21.6 |
| Taller | 64,628 | 25.5 | 28,113 | 25.2 | 2,987 | 25.8 | |
| Average | 134,773 | 53.3 | 59,943 | 53.7 | 6,105 | 52.7 | |
| Total | 253,020 | 111,605 | 11,594 | ||||
| Comparative body size at age 10 | Thinner | 79,326 | 31.3 | 34,402 | 30.7 | 3,890 | 33.5 |
| Plumper | 45,203 | 17.8 | 19,358 | 17.3 | 2,050 | 17.6 | |
| Average | 129,271 | 50.9 | 58,170 | 52.0 | 5,685 | 48.9 | |
| Total | 253,800 | 111,930 | 11,625 | ||||
| Maternal smoking around birth | No | 156,728 | 70.3 | 70,228 | 71.6 | 6,977 | 68.2 |
| Yes | 66,291 | 29.7 | 27,904 | 28.4 | 3,256 | 31.8 | |
| Total | 223,019 | 98,132 | 10,233 | ||||
| Part of a multiple birth | No | 247,777 | 97.7 | 109,292 | 97.6 | 11,242 | 96.9 |
| Yes | 5,928 | 2.3 | 2,637 | 2.4 | 365 | 3.1 | |
| Total | 253,705 | 111,929 | 11,607 | ||||
Based on women with self-reported white ethnicity in UK Biobank. Women providing no answer, answering ‘Prefer not to answer’ or answering ‘Not sure’ were excluded from the analysis.