IRCT20100701004281N3 IRCT 2020-07-13 Shahid Beheshti University of Medical Sciences Effect of Fish Oil Supplement on Pregnancy Outcome in Women with a History of High-risk Pregnancy Investigating the Effect of Fish Oil Supplement on Pregnancy Outcome in Women with a History of High-risk Pregnancy 2015-03-30 anticipated 200 Complete https://irct.ir/trial/48985 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Not used, Assignment: Parallel, Purpose: Health service research, Randomization description: In order to assign patients to two groups of intervention and control, block randomization method with the size of four random blocks was used and randomization sequence was performed in the central committee.The sequence of randomization using web-based randomization is done through the following site: https://www.Randomization.com, Blinding description: In this study, participants were unaware of the study group they were in (intervention or control). Also, the evaluation of the study results (pregnancy outcomes) was performed by a person outside the research team. N/A Increase of blood pressure during current pregnancy. Intervention 1: Intervention group: Soft capsule of 1000 mg salmon oil (Omega 3), without mercury, containing essential fatty acids (fish oil and flaxseed oil) made in Iran, Zahravi Pharmaceutical Company, each capsule of which contains 180 mg of eicosapentaenoic acid and 120 mg Ducosahexaenoic acid, and from the 16th week to the end of pregnancy, one capsule a day was given and it was recommended to be taken orally with food and water; Routine pregnancy care was also provided for this group. Intervention 2: Control group: No intervention was performed and they only received routine pregnancy care. No - There is not a plan to make this available Justification or reason for not sharing IPD is There is not further information