Associations of adherence to the New Nordic Diet with risk of preeclampsia and preterm delivery in the Norwegian Mother and Child Cohort Study (MoBa)

Preeclampsia and preterm delivery are serious complications of pregnancy and leading causes of perinatal mortality and morbidity worldwide. Dietary factors might be associated with these adverse outcomes. We investigated whether adherence to the New Nordic Diet (NND) was associated with preeclampsia and preterm delivery risks in the Norwegian Mother and Child Cohort Study (MoBa). Participants were recruited from all over Norway during the period 1999-2008. A previously constructed diet score assessing meal frequency, and the consumption of Nordic fruits, root vegetables, cabbages, potatoes, oatmeal porridge, whole grains, wild fish, game, berries, milk and water, was used to assess NND adherence. Associations between NND adherence and the outcomes were estimated in adjusted multivariate logistic regression models. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated. A total of 72,072 women was included in the study. High versus low NND adherence was associated with lower risk of total preeclampsia (OR 0.86; 95 % CI 0.78-0.95) and early preeclampsia (OR 0.71; 95 % CI 0.52-0.96). High compared with low NND adherence was associated with a lower risk of spontaneous preterm delivery among nulliparous women (OR 0.77; 95 % CI 0.66-0.89), whereas multiparous women with high NND adherence had a marginally significant higher risk of preterm delivery (OR 1.24; 95 % CI 1.00-1.53). High NND adherence was associated with a lower relative risk of preeclampsia and of spontaneous preterm delivery among nulliparous women; however, among multiparous women there was a higher relative risk of preterm delivery.