Table II.
Distribution of when intake of folic acid-containing supplements began, by maternal characteristics
| Maternal Characteristics | Periconceptional intake, %* (n = 1070) | Early pregnancy intake, %* (n = 667) | Late pregnancy intake, %* (n = 150) | No intake, %* (n = 61) | Total (n = 1948) |
|---|---|---|---|---|---|
| Race-ethnicity | |||||
| Non-Hispanic white | 66 | 28 | 4 | 2 | 1259 |
| Non -Hispanic black | 39 | 43 | 14 | 4 | 236 |
| Hispanic | 30 | 47 | 16 | 7 | 383 |
| Other | 46 | 39 | 11 | 4 | 70 |
| Interview language | |||||
| English | 56 | 34 | 7 | 3 | 1868 |
| Spanish | 19 | 46 | 30 | 5 | 80 |
| Education | |||||
| Less than high school | 26 | 46 | 22 | 7 | 261 |
| High school | 42 | 44 | 10 | 5 | 510 |
| 1–3 years of college | 56 | 35 | 6 | 3 | 552 |
| 4 or more years of college | 77 | 21 | 2 | 1 | 625 |
| Age, yr | |||||
| 13–19 | 25 | 51 | 18 | 6 | 225 |
| 20–24 | 38 | 46 | 12 | 4 | 381 |
| 25–34 | 63 | 30 | 5 | 2 | 1058 |
| 35 or more | 71 | 21 | 5 | 3 | 284 |
| Number of previous live births | |||||
| 0 | 53 | 37 | 8 | 2 | 817 |
| 1 | 59 | 31 | 8 | 3 | 667 |
| 2 or more | 53 | 34 | 8 | 5 | 464 |
| Miscarriage | |||||
| None | 52 | 37 | 8 | 3 | 1522 |
| Any | 66 | 25 | 6 | 3 | 426 |
| Fertility treatments† | |||||
| No | 53 | 36 | 8 | 3 | 1849 |
| Yes | 88 | 9 | 2 | 1 | 99 |
| Vomiting in first trimester | |||||
| At least once per day | 45 | 40 | 9 | 5 | 436 |
| Less than once per day | 54 | 37 | 8 | 1 | 397 |
| Never | 59 | 31 | 7 | 3 | 1115 |
| Cigarette smoking‡ | |||||
| None | 57 | 32 | 8 | 3 | 1558 |
| Any | 46 | 42 | 7 | 5 | 390 |
| Alcohol intake‡ | |||||
| None | 49 | 38 | 9 | 4 | 963 |
| Any | 61 | 31 | 7 | 2 | 985 |
| Recreational drug intake‡ | |||||
| None | 56 | 33 | 8 | 3 | 1846 |
| Any | 34 | 51 | 9 | 6 | 102 |
| First prenatal care visit | |||||
| First trimester | 60 | 35 | 3 | 3 | 1685 |
| Second trimester | 25 | 32 | 40 | 3 | 225 |
| Third trimester or none | 26 | 8 | 42 | 24 | 38 |
| Pregnancy awareness | |||||
| First trimester | 56 | 35 | 6 | 3 | 1885 |
| Second trimester or later | 13 | 16 | 62 | 10 | 63 |
| Daily servings of ready-to-eat breakfast cereal | |||||
| Less than 0.43 | 55 | 32 | 8 | 5 | 480 |
| 0.43 to < 0.86 | 59 | 33 | 7 | 1 | 472 |
| 0.86 to less than 1.14 | 54 | 36 | 7 | 3 | 499 |
| 1.14 or more | 52 | 36 | 9 | 3 | 497 |
| State of residence | |||||
| Arkansas | 57 | 35 | 6 | 2 | 233 |
| California | 39 | 45 | 13 | 4 | 256 |
| Georgia | 58 | 31 | 9 | 2 | 243 |
| Iowa | 63 | 31 | 5 | 1 | 248 |
| Massachusetts | 70 | 24 | 2 | 4 | 244 |
| New Jersey | 62 | 29 | 4 | 5 | 256 |
| New York | 53 | 36 | 9 | 2 | 222 |
| Texas | 38 | 42 | 15 | 5 | 246 |
Periconceptional intake: intake began during the 3 months before conception or the first month after conception; early pregnancy intake: intake began during the second or third month after conception; Late intake: intake began during, the fourth month or Later; no intake: no intake during the 3 months before conception through the time of delivery; only women with continuous intake (ie, intake was continued until delivery) were included in the analysis.
A positive response to any of the following 3 questions served as a marker of maternal subfertility: “Did you have any surgical procedures ... [to help you become pregnant]?”; “in the 2 months before you became pregnant with [baby's name], did you take any medications to help you become pregnant?”; or “did you have any other procedures to help you become pregnant. ...?”).
Any exposure during the during the 3 months before conception through the time of delivery.