Introduction: Idiopathic inflammatory bowel diseases are chronic illnesses, due to immune system disorders, in people with genetic predisposition. IBD often affects women of reproductive age and several medications are available for the treatment of IBD. Since long-term administration is often necessary, required in daily clinical practice to ensure the best possible safety of pharmaceutical treatment during pregnancy. Aim: Investigating the effect of medication on pregnant women with IBD and in addition the effect of drugs on the fetus and the outcome of pregnancy. Method and material: This is a systematic review in which the bibliography research was conducted through electronic databases (Pubmed, Google Scholar, Scopus) in order to identify all prospective, retrospective, cohort studies and controlled randomized or non-clinical trials, which assess the pregnancy outcome under the influence of medication for the treatment of IBD on pregnant women with IBD. Research was made for articles within the period from January 1995 to December 2019,298 studies were found, of which 36 met the criteria. Results: Data analysis shows that the drug treatment of IBD during pregnancy is of low risk in antibiotics and steroids, while metronidazole and ciprofloxacin should be avoided in the first trimester. Aminosalicylics (with the possible exception of Asacol) are considered together with immunomodulators (Thiopurines) and biological agents (anti-TNF) are considered safe to be used during pregnancy. There are insufficient data for the safety of the use of anti-integrins and anti-interleukins. Methotrexate and Thalidomide are contraindicated in pregnancy due to their teratogenic action. Conclusions: Studies have shown that the drugs used to maintain the IBD in remission, except for methotrexate and thalidomide, are of low risk during pregnancy and lactation. Side effects of drugs reported during pregnancy appear to be more related to the activity of the disease than to the drug itself.