Background: Pregnancy is a physiological state in which significant changes in thyroid function occur. Several factors contribute to these changes. These factors could contribute to thyroid dysfunction during pregnancy especially when a deficiency of iodine intake exists and when thyroid reserve is not sufficient. Aim: To study thyroid functions in pregnant women avoiding maternal and fetal complications associated with thyroid dysfunctions. Materials and Methods: A cross-sectional study was carried out on 100 pregnant women attending Obstetrics Outpatient Clinic in Suez-Canal University Hospitals were invited to enroll in the study. At the end of study, the blood samples were assessed for free T3, free T4 and TSH. Results: This study revealed that most of the pregnant women had normal thyroid functions (51%), while subclinical hypothyroidism (39%) was the most prevalent disorder followed by clinical hypothyroidism (6%) and isolated hypothyroxinemia (4%). Conclusion:The most prevalent pattern of thyroid dysfunction in pregnant women was subclinical hypothyroidism.