Development, validity and reproducibility of a food frequency questionnaire in pregnancy for the Universiti Sains Malaysia birth cohort study.

INTRODUCTION: This study aimed to develop and examine the validity and reproducibility of a semi-quantitative food frequency questionnaire (FFQ) among Malay pregnant women in Kelantan, Malaysia. METHODS: A total of 177 Malay pregnant women participated in the validation study while 85 of them participated in the reproducibility study which was carried out in the antenatal clinic of Universiti Sains Malaysia Hospital. The newly developed FFQ was validated against two 24-hour dietary recalls (DR). The FFQ was repeated 20 to 28 days apart. RESULTS: Results showed that the FFQ moderately over-estimated the nutrient and food intakes compared to the DR. Spearman correlation coefficients for nutrients ranged from 0.24 (fat) to 0.61 (calcium) and for foods, ranged from 0.13 (organ meats, onion and garlic) to 0.57 (malt drink). For nutrients, 72 to 85% of women were classified into the correct quartiles from the FFQ and the DR while for foods, 67 to 85% of women were classified correctly. Bland-Altman plot showed relatively good agreement between these two dietary methods. The intra-class correlation (ICC) was used to estimate reproducibility. It ranged from 0.75 (vitamin C) to 0.94 (phosphorus) for nutrients while it ranged from 0.73 (confectionary) to 0.96 (coffee) for foods. CONCLUSION: On average, at least 90% of pregnant women were correctly classified into the quartiles for nutrients and foods from the two sets of the FFQ. The FFQ presented acceptable reproducibility and appears to be a valid tool for categorising pregnant women according to dietary intake.

Higher intake of fruits and vegetables in pregnancy is associated with birth size.

Maternal nutrition has a programming effect on fetal growth. This cross-sectional study investigated the association between maternal micronutrient, fruit and vegetable intake with birth size. Nutrient and food intake were examined using a validated semi-quantitative food frequency questionnaire. One hundred twenty-one pregnant women at 28 to 38 weeks gestation aged 19-40 years, were recruited from the Universiti Sains Malaysia Hospital, Malaysia. Birth weight, length and head circumference were obtained from the medical records. Data were analyzed using multiple linear regression. Results indicate no significant association between any of the measured micronutrients and birth size. However, 2 of the 6 vegetable subgroups and those consumed fruit during pregnancy had children whose birth size was significantly associated with consumption. An increase of 10 g of leafy vegetables per day was associated with a 1.78 cm increase in head circumference (p = 0.04), and tuber vegetable intake was associated with birth length (beta = 0.21, p = 0.03) and head circumference (beta = 0.21, p = 0.01). Fruit intake was associated with birth weight (beta = 0.19, p = 0.04), birth length (beta = 0.20, p = 0.04) and head circumference (beta = 0.19, p = 0.03). The lack of association between maternal nutrient intake and fetal growth and the significant association between fruit and vegetable intake and birth size suggests the existence of other micronutrients and phytochemicals present in foods that play an important role in birth size. The types of nutrients and their roles in birth size warrant further investigation.

Development, Validity and Reproducibility of a Food Frequency Questionnaire in Pregnancy for the Universiti Sains Malaysia Birth Cohort Study

Introduction: This study aimed to develop and examine the validity and reproducibility of a semi-quantitative food frequency questionnaire (FFQ) among Malay pregnant women in Kelantan, Malaysia. Methods: A total of 177 Malay pregnant women participated in the validation study while 85 of them participated in the reproducibility study which was carried out in the antenatal clinic of Universiti Sains Malaysia Hospital. The newly developed FFQ was validated against two 24-hour dietary recalls (DR). The FFQ was repeated 20 to 28 days apart. Results: Results showed that the FFQ moderately over estimated the nutrient and food intakes compared to the DR. Spearman correlation coefficients for nutrients ranged from 0.24 (fat) to 0.61 (calcium) and for foods, ranged from 0.13 (organ meats, onion and garlic) to 0.57 (malt drink). For nutrients, 72 to 85% of women were classified into the correct quartiles from the FFQ and the DR while for foods, 67 to 85% of women were classified correctly. Bland-Altman plot showed relatively good agreement between these two dietary methods. The intra-class correlation (ICC) was used to estimate reproducibility. It ranged from 0.75 (vitamin C) to 0.94 (phosphorus) for nutrients while it ranged from 0.73 (confectionary) to 0.96 (coffee) for foods. Conclusion: On average, at least 90% of pregnant women were correctly classified into the quartiles for nutrients and foods from the two sets of the FFQ. The FFQ presented acceptable reproducibility and appears to be a valid tool for categorising pregnant women according to dietary intake.