title: Validation of a food frequency questionnaire for Japanese pregnant women with and without nausea and vomiting in early pregnancy.
abstract: BACKGROUND
  No previous study has shown the validity of a food frequency questionnaire (FFQ) in early pregnancy with consideration of nausea and vomiting during pregnancy (NVP). The aim of this study was to evaluate the validity of a FFQ in early pregnancy for Japanese pregnant women.
  
  
  METHODS
  We included 188 women before 15 weeks of gestation and compared estimated nutrient intake and food group intake based on a modified FFQ with that based on 3-day dietary records (DRs). Spearman's rank correlation coefficients, adjusting energy intake and attenuating within-person error, were calculated. Subgroup analysis for those with and without NVP was conducted. We also examined the degree of appropriate classification across categories between FFQ and DRs through division of consumption of nutrients and food groups into quintiles.
  
  
  RESULTS
  Crude Spearman's correlation coefficients of nutrients ranged from 0.098 (sodium) to 0.401 (vitamin C), and all of the 36 nutrients were statistically significant. In 27 food groups, correlation coefficients ranged from -0.015 (alcohol) to 0.572 (yogurt), and 81% were statistically significant. In subgroup analysis, correlation coefficients in 89% of nutrients and 70% of food groups in women with NVP and 97% of nutrients and 74% of food groups in women without NVP were statistically significant. On average, 63.7% of nutrients and 60.4% of food groups were classified into same or adjacent quintiles according to the FFQ and DRs.
  
  
  CONCLUSIONS
  The FFQ is a useful instrument, regardless of NVP, for assessing the diet of women in early pregnancy in Japan.
authors.affiliation: Department of Social Medicine, National Research Institute for Child Health and Development, Tokyo, Japan; Center of Maternal-fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development, Tokyo, Japan; Collaborative Departments of Advanced Pediatric Medicine, Graduate School of Medicine, Tohoku University, Sendai, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ogawa
authors.affiliation: Department of Social Medicine, National Research Institute for Child Health and Development, Tokyo, Japan; Center of Maternal-fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Seung-Chik
authors.initials: SC
authors.lastname: Jwa
authors.affiliation: Department of Food Science, Otsuma Women's University, Tokyo, Japan.
authors.forename: Minatsu
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Social Medicine, National Research Institute for Child Health and Development, Tokyo, Japan.
authors.forename: Naho
authors.initials: N
authors.lastname: Morisaki
authors.affiliation: Center of Maternal-fetal, Neonatal and Reproductive Medicine, National Center for Child Health and Development, Tokyo, Japan; Collaborative Departments of Advanced Pediatric Medicine, Graduate School of Medicine, Tohoku University, Sendai, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Sago
authors.affiliation: Department of Social Medicine, National Research Institute for Child Health and Development, Tokyo, Japan. Electronic address: fujiwara-tk@ncchd.go.jp.
authors.forename: Takeo
authors.initials: T
authors.lastname: Fujiwara
mesh_terms: D000328:Adult; D044466:Asian People; D015992:Body Mass Index; D015331:Cohort Studies; D015930:Diet Records; D004034:Diet Surveys; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D007564:Japan; D008875:Middle Aged; D048968:Morning Sickness; D015596:Nutrition Assessment; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D037841:Pregnant People; D011446:Prospective Studies; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
keywords: Food frequency questionnaire; Japan; Nausea; Pregnancy; Validation