TRANSVAGINAL SONOGRAPHIC ASSESSMENT OF THE FETAL URINARY-TRACT IN EARLY-PREGNANCY

Fetal venal size in the first trimester and the early second trimester of pregnancy was evaluated by high-frequency transvaginal sonography in 537 singleton fetuses at risk for cytogenetic abnormality but not a t risk for congenital kidney disease. The percentage of visualization of both kidneys and bladder at different menstrual ages (11-16 weeks) is presented, and centile reference charts for evaluating Kidney growt h have been compiled. All kidney measurements were found to increase a s pregnancy progressed At 13 weeks, fetal kidneys and fetal urinary bl adder were visualized in 92% of the cases screened. The incidence of p yelectasis was high in our population (4.5%), and this pathology was s tudied by other sonographic scans during pregnancy and postnatally. Al l fetuses had normal karyotypes. The results presented provide a refer ence for the assessment of normal renal morphology and growth in early pregnancy.