Renal tract anomalies in the human fetus : prenatal ultrasound and genetic aspects.

In this thesis, attention will be focused on:(i) ultrasonic imaging of normal and abnormal fetal urinary tract anatomy;(ii) the reduced diagnostic potential of ultrasound in oligohydramnios, including methods to circumvent this problem; (iii) the association of ren al tract malforma ti ons and extrarenal and chromosomal anomalies which may have a decisive impact on obstetrie management. The objectives of the present study were: a. to define the role of ultrasound in the prenatal diagnosis of fetal urinary tract malforma ti ons, with particular reference to bilateral renal agenesis, cystic kidney disease and obstructive uropathy; b. to document the incidence and nature of associated extra-renal and chromosome anomalies; c. to assess perinatal outcome following prenatal diagnosis of a fetal urinary tract malformation; d. to establish the possibilities and Iimitations of prenatal ultrasound scanning in pregnancies at risk for a particular renal tract malformation; e. tb determine the potential of intra-uterine diversion techniques in obstructive uropathy

Prenatal diagnosis, management and outcome of fetal uretero-pelvic junction obstruction

Abstract Prenatal diagnosis, management and outcome were studied retrospectively in 24 cases of unilateral and bilateral uretero-pelvie junction obstruction (UPJO). Moderate-to-marked pelvic dilatation was documented in 19 out of 24 cases. The low morbidity and mortality observed in this study are probably determined by the late (third trimester) detection of UPJO, resulting in an underestimation of the prevalence of more severe renal pathology. Amniotic fluid was increased in 4 out of 14 cases of unilateral UPJO and in 5 out of 10 cases of bilateral UPJO, the underlying mechanism of which is still unclear. There was no oligohydramnios. The incidence of extrarenal structural pathology was low, i.e., 3 out of 24 cases. A close agreement could be demonstrated between pre- and postnatal sonographic grading of pelvic dilatation. However, postnatal ultrasonic grading of pelvic dilatation correlated poorly with the degree of functional obstruction as determined by IVP and lasix renography. Despite the severity of pelvic dilatation in the majority of cases, enlarged kidneys were revealed by postnatal clinical examination in only three instances, underlining the importance of prenatal sonographic detection of UPJO

Prenatal diagnosis by ultrasound in pregnancies at risk for autosomal recessive polycystic kidney disease

Abstract In 15 pregnancies at risk of the autosomal recessive type of polycystic kidney disease (ARPKD), there were six recurrences (40%), five of which were diagnosed prenatally between 17 and 26 weeks (mean, 22 weeks). In the remaining affected case, normal kidney size and echogenicity were still present at 30 weeks of gestation. Fetal kidney enlargement and increased echogenicity are the key ultrasonographic signs for the detection of ARPKD. Absent fetal bladder filling and oligohydramnios were only documented in two of the six affected pregnancies. The variability in onset, the intrafamilial variability and the limitations of excluding ARPKD by second trimester ultrasound have to be considered when counselling a couple at risk for this particular disorder