Background
Methods
Study population
Height difference in standard deviations (HD:SDS)
Information on other pubertal milestones
Prenatal exposures and covariates
Background Characteristics | Boys (n = 23,003) No. (%) | Girls (n = 19,846) No. (%) | Missing No. (%) |
---|---|---|---|
Pre-pregnancy BMI | 614 (1.4) | ||
< 18.5 kg/m2 | 984 (4.3) | 833 (4.3) | |
18.5–24.9 kg/m2 | 15,287 (67.4) | 13,119 (67.1) | |
25.0–29.9 kg/m2 | 4437 (19.6) | 3875 (19.8) | |
30.0+ kg/m2 | 1979 (8.7) | 1721 (8.8) | |
Smoking in pregnancy | 41 (0.1) | ||
Non-smoker | 17,382 (75.6) | 14,963 (75.5) | |
Stopped smoking | 2194 (9.5) | 1933 (9.7) | |
1–9 daily cigarettes | 1921 (8.4) | 1667 (8.4) | |
10–14 daily cigarettes | 949 (4.1) | 768 (3.9) | |
15+ daily cigarettes | 532 (2.3) | 499 (2.5) | |
Alcohol in pregnancy | 16 (0.0) | ||
Abstainer | 12,480 (54.3) | 11,036 (55.6) | |
< 1 weekly units | 7199 (31.3) | 6026 (30.4) | |
1–3 weekly units | 2787 (12.1) | 2362 (11.9) | |
> 3 weekly units | 527 (2.3) | 416 (2.1) | |
Maternal age of menarche | 373 (0.9) | ||
Earlier than peers | 5638 (24.7) | 5036 (25.6) | |
Same time as peers | 13,359 (58.6) | 11,278 (57.4) | |
Later than peers | 3819 (16.7) | 3346 (17.0) | |
Highest social class of parents | 89 (0.2) | ||
High grade professional | 5565 (24.2) | 4718 (23.8) | |
Low grade professional | 7271 (31.7) | 6440 (32.5) | |
Skilled worker | 6499 (28.3) | 5552 (28.0) | |
Unskilled worker | 3060 (13.3) | 2620 (13.2) | |
Student | 442 (1.9) | 379 (1.9) | |
Economically inactive | 115 (0.5) | 99 (0.5) | |
Parity | 1 (0.0) | ||
First child | 11,146 (48.5) | 9751 (49.1) | |
Second child or more | 11,856 (51.5) | 10,095 (50.9) | |
Maternal age at delivery, years, mean (sd) | 30.5 (4.2) | 30.4 (4.2) | 23 (0.1) |
Childhood BMI at 7 years, mean (sd) | 15.7 (1.7) | 15.6 (1.8) | 17,008 (39.7) |
Statistical analysis
Results
Study population
Validation of HD:SDS
Correlations for HD:SDS | Correlations for first ejaculation (boys) and menarche (girls) | |||||
---|---|---|---|---|---|---|
Pubertal milestones | No.a | Estimate | 95% CI | No. | Estimate | 95% CI |
Boys | ||||||
Tanner Genital Stage 2 | 6175 | −0.26 | −0.29, − 0.22 | 7679 | 0.28 | 0.24, 0.31 |
Tanner Genital Stage 3 | 6175 | − 0.39 | − 0.41, − 0.36 | 7679 | 0.36 | 0.32, 0.39 |
Tanner Genital Stage 4 | 6175 | −0.44 | − 0.46, − 0.41 | 7679 | 0.38 | 0.35, 0.41 |
Tanner Genital Stage 5 | 6175 | −0.32 | − 0.35, − 0.28 | 7679 | 0.28 | 0.24, 0.31 |
Tanner Pubic Hair Stage 2 | 6179 | −0.30 | − 0.33, − 0.27 | 7679 | 0.30 | 0.26, 0.33 |
Tanner Pubic Hair Stage 3 | 6179 | −0.45 | − 0.47, − 0.42 | 7679 | 0.37 | 0.34, 0.40 |
Tanner Pubic Hair Stage 4 | 6179 | −0.53 | − 0.56, − 0.51 | 7679 | 0.41 | 0.38, 0.44 |
Tanner Pubic Hair Stage 5 | 6179 | −0.44 | − 0.47, − 0.41 | 7679 | 0.37 | 0.34, 0.41 |
Axillary Hair | 6185 | −0.39 | − 0.42, − 0.36 | 7679 | 0.28 | 0.24, 0.31 |
Acne | 6185 | −0.31 | − 0.34, − 0.28 | 7679 | 0.28 | 0.24, 0.31 |
Voice Break | 6015 | −0.34 | − 0.37, − 0.31 | 7485 | 0.34 | 0.31, 0.37 |
First Ejaculation | 6171 | −0.20 | − 0.24, − 0.17 | Ref | ||
Girls | ||||||
Tanner Breast Stage 2 | 5866 | −0.50 | −0.54, − 0.47 | 8111 | 0.63 | 0.61, 0.66 |
Tanner Breast Stage 3 | 5866 | −0.53 | − 0.55, − 0.50 | 8111 | 0.71 | 0.69, 0.72 |
Tanner Breast Stage 4 | 5866 | −0.45 | −0.48, − 0.42 | 8111 | 0.65 | 0.63, 0.67 |
Tanner Breast Stage 5 | 5866 | −0.33 | − 0.36, − 0.29 | 8111 | 0.46 | 0.43, 0.48 |
Tanner Pubic Hair Stage 2 | 5867 | −0.49 | −0.52, − 0.46 | 8111 | 0.61 | 0.59, 0.64 |
Tanner Pubic Hair Stage 3 | 5867 | −0.48 | − 0.50, − 0.45 | 8111 | 0.64 | 0.62, 0.66 |
Tanner Pubic Hair Stage 4 | 5867 | −0.37 | − 0.40, − 0.34 | 8111 | 0.52 | 0.50, 0.55 |
Tanner Pubic Hair Stage 5 | 5867 | −0.30 | − 0.34, − 0.27 | 8111 | 0.40 | 0.37, 0.43 |
Axillary Hair | 5870 | −0.40 | − 0.43, − 0.37 | 8111 | 0.48 | 0.45, 0.50 |
Acne | 5870 | −0.30 | − 0.33, − 0.27 | 8111 | 0.37 | 0.34, 0.40 |
Menarche | 5864 | −0.53 | − 0.55, − 0.51 | Ref |
Prenatal exposures
Boys (n = 22,409) | Girls (n = 19,301) | |||||
---|---|---|---|---|---|---|
Crude | Adjustedb | Crude | Adjustedb | |||
Prenatal exposures | Difference | Difference | 95% CI | Difference | Difference | 95% CI |
Pre-pregnancy BMI | ||||||
< 18.5 kg/m2 | −0.15 | − 0.13 | − 0.19, − 0.06 | − 0.10 | − 0.07 | − 0.14, − 0.01 |
18.5–24.9 kg/m2 | Ref | Ref | Ref | Ref | ||
25.0–29.9 kg/m2 | 0.17 | 0.12 | 0.09, 0.16 | 0.15 | 0.10 | 0.06, 0.13 |
30.0+ kg/m2 | 0.30 | 0.23 | 0.18, 0.28 | 0.26 | 0.19 | 0.14, 0.24 |
Trend analysis (kg/m2) | 0.027 | 0.021 | 0.018, 0.024 | 0.025 | 0.019 | 0.015, 0.022 |
Smoking in pregnancy | ||||||
Non-smoker | Ref | Ref | Ref | Ref | ||
Stopped smoking | −0.01 | −0.01 | −0.05, 0.04 | − 0.03 | −0.04 | − 0.08, 0.01 |
1–9 daily cigarettes | −0.01 | − 0.02 | − 0.07, 0.03 | 0.05 | 0.03 | −0.02, 0.08 |
10–14 daily cigarettes | 0.05 | 0.01 | −0.06, 0.08 | 0.09 | 0.04 | −0.03, 0.11 |
15+ daily cigarettes | 0.03 | −0.02 | −0.11, 0.07 | 0.11 | 0.02 | −0.07, 0.11 |
Trend analysis (group) | 0.007 | −0.003 | −0.017, 0.011 | 0.023 | 0.008 | −0.007, 0.022 |
Alcohol in pregnancy | ||||||
Abstainers | Ref | Ref | Ref | Ref | ||
< 1 units weekly | − 0.01 | 0.00 | −0.03, 0.03 | −0.03 | −0.02 | −0.05, 0.01 |
1–3 units weekly | − 0.05 | − 0.02 | − 0.07, 0.02 | −0.05 | − 0.02 | −0.07, 0.02 |
> 3 units weekly | − 0.16 | − 0.14 | − 0.24, − 0.05 | − 0.01 | 0.00 | −0.10, 0.09 |
Trend analysis (units) | −0.027 | −0.021 | −0.035, − 0.008 | − 0.013 | − 0.006 | − 0.019, 0.007 |
Model 1b: Adjusted difference in HD:SDS when restricting to information on childhood BMI | Model 2c: Adjusted difference in HD:SDS when also adjusting for childhood BMI | |||
---|---|---|---|---|
Prenatal exposures | Difference | 95% CI | Difference | 95% CI |
Boys (n = 13,674) | ||||
Pre-pregnancy BMI | ||||
< 18.5 kg/m2 | −0.17 | −0.26, − 0.08 | − 0.12 | − 0.20, − 0.03 |
18.5–24.9 kg/m2 | Ref | Ref | ||
25.0–29.9 kg/m2 | 0.12 | 0.07, 0.16 | 0.06 | 0.01, 0.10 |
30.0+ kg/m2 | 0.24 | 0.18, 0.31 | 0.13 | 0.06, 0.19 |
Trend analysis (kg/m2) | 0.023 | 0.018, 0.027 | 0.012 | 0.007, 0.016 |
Smoking in pregnancy | ||||
Non-smoker | Ref | Ref | ||
Stopped smoking | 0.00 | −0.05, 0.06 | −0.02 | −0.07, 0.04 |
1–9 daily cigarettes | −0.01 | −0.07, 0.06 | −0.05 | −0.12, 0.01 |
10–14 daily cigarettes | 0.01 | −0.09, 0.11 | −0.04 | −0.13, 0.06 |
15+ daily cigarettes | 0.01 | −0.13, 0.14 | −0.05 | −0.18, 0.08 |
Trend analysis (group) | 0.001 | −0.018, 0.021 | −0.016 | −0.036, 0.003 |
Alcohol in pregnancy | ||||
Abstainers | Ref | Ref | ||
< 1 units weekly | 0.00 | −0.04, 0.04 | 0.00 | −0.04, 0.04 |
1–3 units weekly | 0.00 | −0.06, 0.05 | 0.00 | −0.05, 0.05 |
> 3 units weekly | −0.12 | −0.23, − 0.01 | − 0.11 | − 0.22, 0.00 |
Trend analysis (units) | −0.018 | −0.035, − 0.002 | − 0.017 | − 0.033, 0.000 |
Girls (n = 11,550) | ||||
Pre-pregnancy BMI | ||||
< 18.5 kg/m2 | −0.02 | −0.11, 0.07 | 0.05 | −0.04, 0.14 |
18.5–24.9 kg/m2 | Ref | Ref | ||
25.0–29.9 kg/m2 | 0.10 | 0.06, 0.15 | 0.04 | −0.01, 0.08 |
30.0+ kg/m2 | 0.16 | 0.09, 0.24 | 0.05 | −0.02, 0.11 |
Trend analysis (kg/m2) | 0.018 | 0.014, 0.023 | 0.007 | 0.002, 0.011 |
Smoking in pregnancy | ||||
Non-smoker | Ref | Ref | ||
Stopped smoking | −0.05 | −0.11, 0.00 | −0.08 | −0.14, − 0.02 |
1–9 daily cigarettes | 0.03 | −0.04, 0.10 | −0.03 | −0.09, 0.04 |
10–14 daily cigarettes | 0.05 | −0.06, 0.15 | 0.00 | −0.10, 0.10 |
15+ daily cigarettes | 0.04 | −0.10, 0.19 | −0.02 | −0.16, 0.12 |
Trend analysis (group) | 0.009 | −0.012, 0.029 | −0.012 | −0.032, 0.008 |
Alcohol in pregnancy | ||||
Abstainers | Ref | |||
< 1 units weekly | −0.03 | −0.07, 0.01 | −0.03 | −0.07, 0.01 |
1–3 units weekly | −0.06 | −0.11, 0.00 | −0.06 | −0.12, − 0.01 |
> 3 units weekly | 0.02 | −0.11, 0.14 | 0.00 | −0.12, 0.12 |
Trend analysis (units) | −0.012 | −0.029, 0.006 | −0.014 | −0.031, 0.003 |