Table 1.
Eligible | Provided interview | Provided interview and semen | ||||||
---|---|---|---|---|---|---|---|---|
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n = 3471a | n = 338 | n = 196 | ||||||
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Characteristic at baseline | n | % | n | % | P-valueb | n | % | P-value b |
Mother's race/ethnicity | ||||||||
White | 2275 | 65.6 | 224 | 66.3 | 122 | 62.2 | ||
African American | 850 | 24.5 | 70 | 20.7 | 45 | 23.0 | ||
Hispanic | 89 | 2.6 | 9 | 2.7 | 8 | 4.1 | ||
Asian | 148 | 4.3 | 28 | 8.3 | 17 | 8.7 | ||
Multi-racial/Other | 108 | 3.1 | 7 | 2.1 | 4 | 2.0 | ||
Unknown | 1 | – | – | 0.0082 | – | 0.0288 | ||
Mother's age (quartiles; years) | ||||||||
⩽22 | 809 | 23.4 | 53 | 15.7 | 34 | 17.4 | ||
23–26 | 946 | 27.3 | 75 | 22.3 | 45 | 23.0 | ||
27–31 | 875 | 25.3 | 98 | 29.1 | 58 | 29.6 | ||
30 + | 835 | 24.1 | 111 | 32.9 | 59 | 30.1 | ||
Unknown | 6 | – | 1 | – | <0.0001 | – | 0.0402 | |
Mother's parity | ||||||||
Primiparous | 1086 | 31.3 | 71 | 21.0 | 37 | 18.9 | ||
Multiparous | 2385 | 68.7 | 267 | 79.0 | <0.0001 | 159 | 81.1 | 0.0002 |
Mother's education | ||||||||
Less than high school | 559 | 16.2 | 48 | 14.2 | 29 | 14.8 | ||
High school/trade school | 1138 | 32.9 | 113 | 33.4 | 64 | 32.7 | ||
College | 1764 | 51.0 | 177 | 52.4 | 103 | 52.6 | ||
Unknown | 10 | – | – | – | 0.6442 | – | 0.8582 | |
Mother's employment | ||||||||
Homemaker | 1859 | 55.8 | 214 | 64.7 | 122 | 63.5 | ||
Professional/managerial | 387 | 11.6 | 33 | 10.0 | 20 | 10.4 | ||
Secretarial/clerical | 853 | 25.6 | 64 | 19.3 | 36 | 18.8 | ||
Laborer (housework/factory) | 225 | 6.8 | 17 | 5.1 | 11 | 5.7 | ||
Other | 10 | 0.3 | 3 | 0.9 | 3 | 1.6 | ||
Unknown | 137 | – | 7 | – | 0.0075 | 4 | – | 0.0084 |
Mother's smoking | ||||||||
Never | 1634 | 49.1 | 169 | 51.2 | 98 | 51.0 | ||
Current | 1131 | 34.0 | 93 | 28.2 | 47 | 24.5 | ||
Past | 566 | 17.0 | 68 | 20.6 | 47 | 24.5 | ||
Unknown | 140 | – | 8 | – | 0.0626 | 4 | – | 0.0044 |
Mother's coffee consumption (quartiles) | ||||||||
<1/2 cup per day | 699 | 23.4 | 67 | 24.8 | 44 | 27.3 | ||
1/2–1 cup per day | 680 | 22.8 | 49 | 18.2 | 28 | 17.4 | ||
2–3 cups per day | 806 | 27.0 | 69 | 25.6 | 46 | 28.6 | ||
4 + cups per day | 798 | 26.8 | 85 | 31.5 | 43 | 26.7 | ||
Unknown | 488 | – | 68 | – | 0.1850 | 35 | – | 0.3767 |
Mother's alcohol consumption (quartiles) | ||||||||
<1 drink per weekc | 1327 | 44.5 | 131 | 48.5 | 76 | 47.2 | ||
1–2 drinks per week | 1072 | 35.9 | 83 | 30.7 | 53 | 32.9 | ||
3 + drinks per week | 585 | 19.6 | 56 | 20.7 | 32 | 19.9 | ||
Unknown | 487 | – | 68 | – | 0.2296 | 35 | – | 0.7234 |
Offspring birth weight (quartiles; g) | ||||||||
⩽2940 | 686 | 19.8 | 64 | 18.9 | 40 | 20.4 | ||
2941–3276 | 839 | 24.2 | 76 | 22.5 | 45 | 23.0 | ||
3277–3584 | 884 | 25.5 | 89 | 26.3 | 53 | 27.0 | ||
⩾3585 | 1062 | 30.6 | 109 | 32.3 | 0.8410 | 58 | 29.6 | 0.9417 |
Offspring gestational age (quartiles; weeks) | ||||||||
⩽38 | 772 | 22.4 | 71 | 21.2 | 53 | 27.0 | ||
39 | 779 | 22.6 | 81 | 24.2 | 40 | 20.4 | ||
40 | 858 | 24.9 | 76 | 22.7 | 43 | 21.9 | ||
⩾41 | 1031 | 30.0 | 107 | 31.9 | 60 | 30.6 | ||
Unknown | 31 | – | 3 | – | 0.6711 | – | 0.4168 |
CHDS, Child Health and Development Studies.
Bold values are significant at P < 0.05.
Quartiles are based on the distribution of variables among all CHDS births. For birth weight and gestational age, quartile cutpoints were based on the distribution among liveborn CHDS births.
Eligible sample size is equivalent to total eligible (n = 3809) minus participants (n = 338).
Based on chi-square test of distribution. P-values for participants are given for the comparison of distributions between the eligible sample (n = 3471) and the participant sample (n = 338), and the comparison between the eligible sample and the sample that also provided semen (n = 196).
Owing to clumping of data, quartiles 1 and 2 are combined at this cutpoint.