. | High SES . | Medium SES . | Low SES . | |||
---|---|---|---|---|---|---|
. | Mean % . | N (SD) . | Mean % . | N (SD) . | Mean % . | N (SD) . |
Birth Outcomes | ||||||
PTB | 5.77 | 85,618 | 6.39 | 73,238 | 7.72 | 100,527 |
LBWa | 4.74 | 68,611 | 5.45 | 60,664 | 6.74 | 84,158 |
VLBWa | 0.54 | 7,743 | 0.64 | 7,178 | 0.85 | 10,648 |
Newborn | ||||||
Sex (male) | 51.64 | 873,722 | 51.62 | 723,225 | 51.58 | 671,425 |
Firstborn | 54.15 | 803,006 | 56.95 | 652,735 | 50.64 | 659,191 |
Mother | ||||||
Mother is married | 95.4 | 1,614,298 | 78.06 | 894,598 | 64.61 | 841,018 |
Mother's age | 33.19 | (4.18) | 31.91 | (4.75) | 29.49 | (5.62) |
Non-Spanish | 4.6 | 77,767 | 5.68 | 65,086 | 18.11 | 235,803 |
Contextual Characteristics | ||||||
Female employment | 0.44 | (0.11) | 0.43 | (0.11) | 0.43 | (0.11) |
Share of females with tertiary degree | 0.39 | (0.11) | 0.39 | (0.13) | 0.39 | (0.13) |
Population density (per km2) | 348.44 | (291.80) | 295.63 | (279.01) | 239.70 | (256.40) |
ln(GDP) | 10.33 | (1.31) | 10.12 | (1.28) | 9.84 | (1.30) |
Vegetation's leaf area index (m2/m2) | 2.01 | (0.79) | 2.06 | (0.69) | 2.04 | (0.82) |
Climate | ||||||
Solar radiation (W/m2) | 1,017 | (4.35) | 1,017 | (4.35) | 1,017 | (4.32) |
Relative humidity (%) | 66.25 | (11.91) | 66.50 | (11.64) | 67.01 | (11.26) |
Precipitation (mm/day) | 1.34 | (1.48) | 1.29 | (1.45) | 1.28 | (1.46) |
Wind speed (m/sec) | 0.36 | (0.90) | 0.34 | (0.94) | 0.31 | (0.98) |
Temperature | ||||||
Cold days (<5°C/ <41°F) | 13.11 | (17.55) | 13.08 | (19) | 12.88 | (19.15) |
Comfort zone (5°C– 25°C/41°F–77°F) | 228.36 | (26.42) | 227.77 | (26.50) | 227.94 | (26.88) |
Warm days (>25°C–32°C/ >77°F–89.6°F) | 32.14 | (25.7) | 32.74 | (26.11) | 26.72 | (26.72) |
Hot days (>32°C/ >89.6°F) | 0.31 | (1.39) | 0.33 | (1.42) | 0.35 | (1.42) |
% SES | 37.73 | 1,482,984 | 29.16 | 1,146,060 | 33.12 | 1,301,743 |
. | High SES . | Medium SES . | Low SES . | |||
---|---|---|---|---|---|---|
. | Mean % . | N (SD) . | Mean % . | N (SD) . | Mean % . | N (SD) . |
Birth Outcomes | ||||||
PTB | 5.77 | 85,618 | 6.39 | 73,238 | 7.72 | 100,527 |
LBWa | 4.74 | 68,611 | 5.45 | 60,664 | 6.74 | 84,158 |
VLBWa | 0.54 | 7,743 | 0.64 | 7,178 | 0.85 | 10,648 |
Newborn | ||||||
Sex (male) | 51.64 | 873,722 | 51.62 | 723,225 | 51.58 | 671,425 |
Firstborn | 54.15 | 803,006 | 56.95 | 652,735 | 50.64 | 659,191 |
Mother | ||||||
Mother is married | 95.4 | 1,614,298 | 78.06 | 894,598 | 64.61 | 841,018 |
Mother's age | 33.19 | (4.18) | 31.91 | (4.75) | 29.49 | (5.62) |
Non-Spanish | 4.6 | 77,767 | 5.68 | 65,086 | 18.11 | 235,803 |
Contextual Characteristics | ||||||
Female employment | 0.44 | (0.11) | 0.43 | (0.11) | 0.43 | (0.11) |
Share of females with tertiary degree | 0.39 | (0.11) | 0.39 | (0.13) | 0.39 | (0.13) |
Population density (per km2) | 348.44 | (291.80) | 295.63 | (279.01) | 239.70 | (256.40) |
ln(GDP) | 10.33 | (1.31) | 10.12 | (1.28) | 9.84 | (1.30) |
Vegetation's leaf area index (m2/m2) | 2.01 | (0.79) | 2.06 | (0.69) | 2.04 | (0.82) |
Climate | ||||||
Solar radiation (W/m2) | 1,017 | (4.35) | 1,017 | (4.35) | 1,017 | (4.32) |
Relative humidity (%) | 66.25 | (11.91) | 66.50 | (11.64) | 67.01 | (11.26) |
Precipitation (mm/day) | 1.34 | (1.48) | 1.29 | (1.45) | 1.28 | (1.46) |
Wind speed (m/sec) | 0.36 | (0.90) | 0.34 | (0.94) | 0.31 | (0.98) |
Temperature | ||||||
Cold days (<5°C/ <41°F) | 13.11 | (17.55) | 13.08 | (19) | 12.88 | (19.15) |
Comfort zone (5°C– 25°C/41°F–77°F) | 228.36 | (26.42) | 227.77 | (26.50) | 227.94 | (26.88) |
Warm days (>25°C–32°C/ >77°F–89.6°F) | 32.14 | (25.7) | 32.74 | (26.11) | 26.72 | (26.72) |
Hot days (>32°C/ >89.6°F) | 0.31 | (1.39) | 0.33 | (1.42) | 0.35 | (1.42) |
% SES | 37.73 | 1,482,984 | 29.16 | 1,146,060 | 33.12 | 1,301,743 |
Notes: Descriptive statistics are displayed by SES and exclude those without SES information and those who are inactive. These statistics are computed on the largest sample for each SES group. N = 3,930,787.
The overall number of observations for LBW and VLBW is 3,807,535 births.