Objective. To analyze voice changes in 29 women with low pitch during pregnancy. Methods. Clinical features, voice characteristics and laryngoscopic signs, changes in hormone levels, and prognosis in 29 women with low pitch during pregnancy were retrospectively analyzed and compared with data from 30 age-matched nonpregnant controls. Results. Compared with controls, there was a statistically significant reduction in pitch in the patients. This occurred in the first trimester of their pregnancies in 7/29 patients (27.5%), in the second trimester in 17 (58.6%), and in the third trimester in 5 (17.2%). Of 22 patients who had data on hormonal levels, 9 patients (40.9%) had abnormal hormone levels. Of the remaining seven patients with no hormonal data, three had acne, rough skin, or thick hair during pregnancy. Among the 23 patients who were followed up, 1 (4.3%) recovered to normal pitch 6 months postpartum, 12 (52.2%) had higher pitch but this did not return to normal levels, and 10 (43.5%) showed no significant improvement in phonation. Conclusions. Low pitch during pregnancy occurs most frequently in the second trimester and is more likely to occur when the fetus is a boy. Mucosal edema of vocal folds is common and is closely related to changes in hormone levels during pregnancy. After delivery, the pitch of some patients can improve, and some return to normal pitch.