Table 3.
Percentage of study participants in selected risk groupsa who had low dietary intake or high dietary intakeb of selected nutritional factors, by maternal age group, parity, folic acid–containing vitamin supplement intake, and smoking status, and whether these percentages were significantly different from the reference groups, among control mothers who participated in the National Birth Defects Prevention Study, 1997-2011c
| Age Groupd | Paritye | No Folic Acid–Containing Vitamin Supplement Intake During 3 Months Before Pregnancyf | Smoking During 1 Month Before Pregnancyg | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Aged <20 | Aged ≥35 | Nulliparous | ≥3 Previous Live Births | |||||||||
| Factor | % Low | % High | % Low | % High | % Low | % High | % Low | % High | % Low | % High | % Low | % High |
| Positively scored factors | ||||||||||||
| Diet quality indexh | 17.5i | 5.3i | 6.0j | 15.0j | 11.3i | 10.8j | 8.4 | 8.2 | 11.5i | 9.0i | 17.9i | 5.9i |
| Nutrients | ||||||||||||
| Beta carotene | 23.3i | 5.0i | 2.5j | 16.4j | 11.7i | 9.3 | 7.1j | 10.7 | 12.7i | 9.3 | 17.0i | 5.2i |
| Calcium | 19.9i | 5.8i | 6.2j | 12.5j | 11.2i | 10.4 | 9.0 | 9.2 | 12.1i | 8.0i | 17.2i | 8.1 |
| Choline | 20.6i | 8.9 | 4.3j | 11.4 | 12.0i | 10.0 | 7.1 | 13.4j | 11.8i | 10.6j | 17.5i | 9.5 |
| Folate | 17.2i | 9.3 | 5.5j | 10.7 | 11.6i | 10.6j | 8.6 | 8.9 | 11.5i | 9.4 | 17.7i | 9.7 |
| Iron | 16.2i | 10.0 | 9.2 | 10.0 | 11.5i | 10.3 | 10.0 | 9.0 | 10.7i | 9.8 | 15.0i | 10.5 |
| Lycopene | 22.6i | 10.4j | 4.3j | 8.9i | 11.3i | 9.6 | 8.4 | 13.7j | 12.4i | 11.3j | 13.7i | 7.6i |
| Niacin | 20.2i | 7.5 | 5.2j | 10.7 | 11.1i | 11.1j | 9.9 | 8.4 | 12.1i | 9.6 | 14.9i | 10.3 |
| Retinol | 15.3i | 10.3 | 7.6j | 8.9 | 11.6i | 9.4 | 8.8 | 13.4j | 11.2i | 11.0j | 12.4i | 9.0 |
| Riboflavin | 20.6i | 6.2i | 3.9j | 13.9j | 12.0i | 10.6 | 7.7 | 8.3 | 12.1i | 8.9i | 16.9i | 12.1j |
| Thiamin | 17.4i | 9.8 | 4.7j | 10.5 | 11.0i | 10.4 | 8.2 | 9.0 | 11.7i | 9.6 | 18.8i | 8.8 |
| Vitamin A | 22.1i | 7.5 | 4.2j | 12.1j | 11.8i | 8.8i | 7.1 | 13.4j | 12.3i | 10.7j | 15.8i | 6.4i |
| Vitamin C | 13.3i | 12.2j | 4.9j | 11.5 | 10.3 | 9.7 | 6.9j | 12.8j | 10.9i | 11.6j | 18.7i | 6.1i |
| Fruits | 13.9i | 12.1j | 6.3j | 11.9j | 10.8 | 9.6 | 7.8 | 12.7j | 11.4i | 10.7j | 21.7i | 5.0i |
| Vegetables | 24.8i | 8.0 | 4.5j | 13.5j | 11.6i | 9.8 | 7.3 | 14.4j | 12.3i | 10.3j | 14.6i | 7.7i |
| Dairy | 16.2i | 6.4i | 7.6j | 10.8 | 11.3i | 9.8 | 8.8 | 10.2 | 11.3i | 8.3i | 15.6i | 8.3 |
| Grains | 16.4i | 10.9j | 8.6 | 10.0 | 11.3i | 10.2 | 9.5 | 8.8 | 11.3i | 10.1 | 15.3i | 8.8 |
| % Calories from protein | 24.5i | 4.9i | 3.6j | 12.4 | 11.7i | 10.7j | 8.6 | 8.9 | 12.9i | 9.2i | 17.6i | 10.4j |
| Negatively scored factors | ||||||||||||
| Sweets | 5.4i | 21.2i | 14.3j | 3.5j | 9.7 | 10.9i | 11.4 | 8.5 | 8.9i | 12.6i | 9.4 | 21.6i |
| Glycemic index | 6.1i | 19.6i | 14.7j | 3.1j | 9.5 | 12.0i | 12.5j | 8.0 | 9.1i | 12.3i | 5.5i | 21.8i |
| % Calories from fat | 14.3j | 8.1 | 7.7i | 11.0 | 10.2 | 9.2 | 9.3 | 11.0 | 11.6j | 9.6 | 11.1j | 13.4i |
| % Calories from saturated fat | 14.5j | 8.3 | 7.2i | 10.0 | 10.5 | 9.5 | 9.2 | 9.6 | 11.7j | 9.2j | 10.5 | 11.7i |
a Risk groups were defined on the basis of selected characteristics associated with adverse maternal and infant health outcomes.
b High intake refers to dietary intake >90th percentile, and low intake refers to dietary intake <10th percentile; percentiles were based on the distribution of dietary intake among all study participants (Table 1 presents percentile cutoffs).
c Data source: Yoon et al.14
d Reference group was participants aged 20-34.
e Reference group was participants with 1 or 2 previous live births.
f Reference group was participants who did take folic acid–containing vitamin supplements during the 3 months before pregnancy.
g Reference group was participants who did not smoke during the 3 months before pregnancy.
h A summary score of 6 positively scored components (grains, vegetables, fruits, folate, iron, and calcium) and 2 negatively scored components (intake of sweets and percentage of calories from fat). For each participant, we scored each component from 0 to 3 on the basis of quartiles of the distribution among controls, and then we summed the component scores to obtain the final value for the DQI; the score could range from 0 to 18, and a higher score indicates better diet quality. Index is based on a previously validated index17,18 adapted to the National Birth Defects Prevention Study food frequency questionnaire.19
i Risk group had significantly (P < .05) worse intake than reference group, as determined by Pearson χ2 tests. That is, for positively scored nutrients, a larger percentage of participants than expected had low intake (ie, >10% had intake <10th percentile) or a smaller percentage of participants than expected had high intake (ie, <10% had intake >90th percentile). For negatively scored nutrients, a smaller percentage of participants than expected had low intake (ie, <10% had intake <10th percentile) or a larger percentage of participants than expected had high intake (ie, >10% had intake >90th percentile).
j Risk group had significantly (P < .05) better intake than reference group, as determined by Pearson χ2 tests. For positively scored nutrients, a smaller percentage of participants than expected had low intake (ie, <10% had intake <10th percentile) or a larger percentage of participants than expected had high intake (ie, >10% had intake >90th percentile). For negatively scored nutrients, a larger percentage of participants than expected had low intake (ie, >10% had intake <10th percentile) or a smaller percentage of participants than expected had high intake (ie, <10% had intake >90th percentile).