Background: Iron deficiency anemia (IDA) is considered one of the leading problems in pregnancy.Objective: To compare the impact of doubling the standard dose of oral iron ferrous fumarate versus I.V iron sucrose to improve Hb, and S.ferritin levels in pregnancy for those women suffering from IDA between fourteen and thirty four week of gestation. Patients and Methods:This was a controlled randomized clinical trial done over five hundred women with gestational age between fourteen and thirty four weeks in the department of Obstetrics and Gynecology at Al-Sayd Galal Hospital, from June 2019 to October 2020. All pregnant women included were counselled with an informed consent obtained before beginning of this study. Pregnant women were randomly divided into 2 equal groups: Group A for ferrous fumarate oral iron therapy while Group B for parenteral iron sucrose therapy. Pregnant women precipitating in this study were asked for medical history in details. Also they had undergone clinical examination and laboratory investigations including CBC and S. ferritin pretreatment and post treatment. Results:The parenteral iron sucrose had more significant results than doubling the dose of ferrous fumarate oral iron treating IDA women during pregnancy. Few side effects were detected, and thus, it considered as a useful and alternative formulation in treatment of IDA. So, i.v iron sucrose infusion was more favorable for doubling the standard dose of ferrous fumarate as anaphylaxis risk was minimal. On the contrary, noncompliance to ferrous fumarate oral iron increased with doubling the dose. Parental iron showed a faster and more significant response than that for oral iron because of increased amount of iron available for Hb synthesis in the bone marrow when treating women using I.V iron therapy. Conclusion:Parenteral iron sucrose has better results than that when using double the standard dose oral iron ferrous fumarate treating IDA in women during pregnancy as I.V iron improves the concentration of Hb and S.ferritin more significant than oral iron therapy.