Our aim was to estimate associations of adolescent dietary patterns and meal habits with hypertensive disorders of pregnancy (HDP) and preterm birth. We used data from a prospective cohort study (Norwegian Young-HUNT1) where dietary information was collected during adolescence and pregnancy outcomes were obtained through record linkage to the Norwegian national birth registry. The outcomes were HDP, hypertension, pre-eclampsia/eclampsia, and preterm birth in the first pregnancy and in any pregnancy. Diet was self-reported from validated questionnaires, and exposures were dietary indexes (healthy; unhealthy; fruit and vegetable; fibre index) and meal habits. Recruitment took place in schools. Eligible participants were females aged 13–19 years at the time of dietary assessment with a subsequent singleton pregnancy (n 3622). Women who reported a higher fibre intake in adolescence had a lower risk of pre-eclampsia in the first pregnancy (Relative Risk: 0·84; 95 % CI 0·7, 1·0), although this was weaker in sensitivity analyses. Regular meal habits in mid-adolescence (aged 13–15 years), particularly breakfast and lunch, were weakly associated with a lower risk of hypertension in pregnancy. Our results are the first to indicate an association between aspects of diet and dietary behaviour in mid-adolescence and subsequent HDP. More evidence is needed from larger studies to replicate the results and from alternative study designs to disentangle causality.
