Objectives: Patients who use substances or those who are on opioid maintenance therapy could be at risk of inadequate nutrition. These inadequacies could translate to adverse outcomes during pregnancy. The objective of this study was to determine differences in dietary macro and micronutrient intake in pregnant women on OMT compared to healthy controls. Methods: Participants from a parent prospective cohort study ENRICH\u27 were classified into two groups: OMT users and healthy controls. Inclusion into the nutritional analysis was based on eligibility criteria of completion of food frequency questionnaire administered during hospital stay after delivery, absence of heavy drinking and adequate energy intake. Crude differences in energy, macro (carbohydrate, protein and total fat) and micronutrient (vitamin A, B1, B2, B6, B12, C, D, E, beta-carotenes, folate, iron and choline) intake between the study groups were compared using student\u27s t-test which was repeated after adjustment by total energy intake. To control for multiple comparisons MANOVA was used. Multivariate regression was used to control for confounders. Results: A total of 54 subjects (34 OMT and 20 controls) were included in the nutritional analyses. No significant effect of OMT status on energy intake was observed. It was observed that OMT group had lower energy adjusted protein intake (p=0.03). Analysis of the dietary micronutrient intake showed that the subjects on OMT had significantly lower Vitamin E (-0.9a-TE/1000Kcal/day, 95%CI:-1.8, 0.1, p=0.03) and folate (-45.9 DFE/1000Kcal/day, 95%CI:-87.1,-4.6, p=0.03) intake compared to controls after controlling for marital status, insurance type, age and BMI. There was a significant effect of ethnicity on energy-adjusted carbohydrate intake (p=0.02) and employment (p\u3c0.01) on energy-adjusted protein intake after controlling covariates. It was observed that diet alone was not able to meet the requirements of several micronutrients in both the OMT and control group. Conclusion: It was observed that pregnant women on OMT had lower intake of several micronutrients compared to healthy controls which could lead to adverse pregnancy outcomes. The results of this study reinforces the requirement of micronutrient supplementation during pregnancy. Future studies should focus on investigating the effect of these differences in pregnancy outcomes and implement policies to promote healthy diet
