Background: Thyroid dysfunction in pregnancy may be accompanied by both maternal and fetal complications. Hypothyroidism in pregnancy is associated with premature birth, fetal cardiac complications, low birth weight, increased frequency of cesarean delivery, placental complications, preeclampsia and gestational hypertension, perinatal morbidity-mortality, and cognitive dysfunction. Objective: The aim of the current work was to study early diagnosis of thyroid dysfunction in pregnant women for better health care. Patients and method: A prospective cross-sectional study was conducted at Gynecology and Obstetrics Department, Abukabir Central Hospital in co-operation with Gynecology and Obstetrics Department, Zagazig University hospitals on 229 healthy pregnant women with uncomplicated singleton pregnancy and without history of previous thyroid problems. Detailed medical and obstetrical history were taken from all selected participants, and they were subjected to thorough clinical examination. Routine laboratory and ultrasonographic examination were also performed to all of them. Results: Participants were divided into 4 groups including those with Euthyroid, subclinical hypothyroidism, subclinical hypothyroidism was the most prevalent disorder (7.9%) followed by overt hypothyroidism (3.5%) and subclinical hyperthyroidism (0.87%). No cases with overt hyperthyroidism were reported. There was no statistically significant difference between the 4 groups as regard age. Regarding BMI, results showed that patients with overt hypothyroidism had significantly higher BMI than those in the other groups. Also, there were no statistically significant differences between different groups regarding gravidity, parity, and gestational ages. Conclusion: It could be concluded that most pregnant women have normal thyroid functions (Euthyroid). The most prevalent pattern of thyroid dysfunction in pregnant women is subclinical hypothyroidism.