Objective: To investigate the associations of organic food consumption with maternal pre-pregnancy BMI, hypertension and diabetes in pregnancy, and several blood biomarkers of pregnant women. Design: Prospective cohort study. Setting: Pregnant women were recruited at midwives' practices and through channels related to consumption of food from organic origin. Subjects: Pregnant women who filled in FFQ and donated a blood sample (n 1339). Participant groups were defined based on the share of consumed organic products; to discriminate between effects of food origin and food patterns, healthy diet indicators were considered in some statistical models. Results: Consumption of organic food was associated with a more favourable pre-pregnancy BMI and lower prevalence of gestational diabetes. Compared with participants consuming no organic food (reference group), a marker of dairy products intake (pentadecanoic acid) and trans-fatty acids from natural origin (vaccenic and rumenic acids) were higher among participants consuming organic food (organic groups), whereas elaidic acid, a marker of the intake of trans-fatty acids found in industrially hydrogenated fats, was lower. Plasma levels of homocysteine and 25-hydroxyvitamin D were lower in the organic groups than in the reference group. Differences in pentadecanoic acid, vaccenic acid and vitamin D retained statistical significance when correcting for indicators of the healthy diet pattern associated with the consumption of organic food. Conclusions: Consumption of organic food during pregnancy is associated with several health-related characteristics and blood biomarkers. Part of the observed associations is explained by food patterns accompanying the consumption of organic food.