TABLE 1.
Sample characteristics of US pregnant women ages 20–39 y in NHANES 1999–20141
| N | Percentage (95% CI) | |
|---|---|---|
| Age at screening, y | ||
| 20–24 | 410 | 29.6 (25.9, 33.3) |
| 25–29 | 415 | 31.6 (28.0, 35.1) |
| 30–34 | 310 | 24.9 (20.9, 29.0) |
| 35–39 | 130 | 13.9 (10.7, 17.1) |
| Race/ethnicity | ||
| Non-Hispanic white | 565 | 54.1 (48.8, 59.5) |
| Mexican American | 336 | 14.3 (11.5, 17.0) |
| Non-Hispanic black | 195 | 15.9 (12.6, 19.2) |
| Other | 169 | 15.7 (11.5, 19.9) |
| Poverty level | ||
| Missing | 87 | 7.4 (4.9, 9.8) |
| PIR <130% | 391 | 24.3 (20.8, 27.7) |
| PIR 130 to <350% | 418 | 32.9 (28.7, 37.2) |
| PIR ≥350% | 369 | 35.4 (30.2, 40.7) |
| Education level | ||
| Missing | 1 | <1 (0, 0.9)2 |
| Less than high school | 325 | 18.5 (15.3, 21.6) |
| HS diploma or GED | 268 | 18.8 (15.3, 22.2) |
| Some college | 359 | 31.8 (27.8, 35.9) |
| College degree | 312 | 30.9 (26.7, 35.1) |
| Marital status | ||
| Missing | 40 | 3.7 (1.9, 5.5) |
| Married | 811 | 63.6 (59.2, 68.1) |
| Not married | 414 | 32.6 (28.4, 36.9) |
| Trimester | ||
| Missing | 177 | 20.6 (16.5, 24.7) |
| 1st (1–3 mo) | 257 | 24.1 (20.7, 27.5) |
| 2nd (4–6 mo) | 426 | 28.0 (24.3, 31.6) |
| 3rd (7–10 mo) | 405 | 27.3 (23.6, 31.0) |
| Prepregnancy BMI2 | ||
| Missing | 25 | 2.1 (0.7, 3.6)2 |
| Underweight | 68 | 5.9 (3.8, 8.0) |
| Normal weight | 658 | 50.3 (45.9, 54.7) |
| Overweight | 287 | 23.4 (19.9, 26.9) |
| Obese | 227 | 18.3 (15.1, 21.5) |
| Physician-diagnosed diabetes | 15 | 1.3 (0.2, 2.4)2 |
1
n = 1265. HS, high school; PIR, poverty to income ratio.
2
Relative SE >30%. Column percentages are survey-weighted.