A prospective study of the association between isolated fetal pyelectasis and chromosomal abnormality

• Published in: Obstetrics and gynecology (New York. 1953) Vol. 88; no. 3; pp. 379 - 382
• Main Authors: Wickstrom, Elizabeth A., Thangavelu, Maya, Parilla, Barbara V., Tamura, Ralph K., Sabbagha, Rudy E.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-09-1996; Elsevier Science
• Subjects: Adult; Amniocentesis; Biological and medical sciences; Chorionic Villi Sampling; Chromosome Aberrations - diagnosis; Chromosome Aberrations - epidemiology; Chromosome Disorders; Dilatation, Pathologic - diagnostic imaging; Dilatation, Pathologic - epidemiology; Down Syndrome - diagnosis; Down Syndrome - epidemiology; Female; Fetal Diseases - diagnostic imaging; Fetal Diseases - epidemiology; Gynecology. Andrology. Obstetrics; Humans; Incidence; Karyotyping; Kidney Pelvis - diagnostic imaging; Kidney Pelvis - embryology; Management. Prenatal diagnosis; Maternal Age; Medical sciences; Pregnancy; Pregnancy. Fetus. Placenta; Prospective Studies; Risk Factors; Ultrasonography, Prenatal; Chromosomal aberration; Sonography; Human; Amniocentesis; Urinary system disease; Congenital; Aneuploidy; Renal disease; Down syndrome; Congenital disease; Hydronephrosis; Incidence; Prenatal; Fetal diseases; Malformation; Echography; Risk factor; Abnormal chromosome; Fetus; Diagnosis
• ISSN: 0029-7844; 1873-233X
• DOI: 10.1016/0029-7844(96)00211-6

To determine the incidence of chromosomal abnormalities among fetuses with isolated pyelectasis.
Between March 1991 and March 1994, 121 cases of isolated fetal pyelectasis were identified at our institution. Pyelectasis was defined as a renal pelvis anteroposterior diameter of at least 4 mm before 33 weeks' gestation, and at least 7 mm at 33 weeks or thereafter. Once identified, women were offered antenatal genetic testing; if they declined, consent was sought for umbilical cord blood studies at delivery.
Chromosomal evaluation was available in 99 women. Two chromosomal abnormalities were identified: one trisomy 21 and one mosaic 46,XY/47,XYY. The ages of the women were 32 and 28 years, respectively. Calculation of adjusted risks for Down syndrome and all chromosomal abnormalities indicated a 3.9-fold increase in Down syndrome risk and a 3.3-fold increase in risk for all chromosomal abnormalities in the presence of isolated fetal pyelectasis.
Isolated fetal pyelectasis is associated with increased risk, over that related to age, for both Down syndrome and all chromosomal abnormalities. These factors may be valuable in counseling individual patients regarding the appropriateness of amniocentesis.