ABSTRACT
OBJECTIVE: Ultrasonography was used to determine not only the size but also the shape and site of gestational sac (GS) in early pregnancy. This study was performed to evaluate the role of transvaginal ultrasonography to predict placenta previa in early pregnancy, and analyze the correlation of the GS location with pregnancy outcomes. METHODS: From 1995 to 2007, medical records of pregnant women who had diagnosed placenta previa at Kangnam St. Mary's Hospital and Our Lady of Mercy Hospital were reviewed retrospectively. 71 patients with placenta previa had transvaginal ultrasonographic evidences within 7 weeks of gestation. As a control group, randomized sampling among pregnant women without placenta previa was performed, and 102 patients were selected and reviewed. Data was analyzed with SPSS version 11.0 statistically. RESULTS: 23.9% of GS (n=17) were found in lower 1/3 of the uterine cavity, 31.0% (n=22) were in middle 1/3, while 45.1% (n=32) were in upper 1/3. The distribution of GS in placenta previa patients leans to the lower in uterine cavity compared to normal pregnancies significantly (P=0.000). The relationship between the location of GS and differential diagnosis of placental previa was not statistically significant. CONCLUSION: Our results show that there would be higher risk for placenta previa, preterm labor, and early delivery when ultrasonographic finding of GS within 7 weeks of gestation reveals lower implantation in uterine cavity.