title: Prenatal renal vein thrombosis in dichorionic twin pregnancy.
abstract: BACKGROUND
  Prenatal renal vein thrombosis is a rarely described diagnostic finding. The etiology is unclear in the majority of cases, although thrombophilia was found in some affected fetuses. Precise ultrasound scan can improve detection rate of neonatal thrombosis due to characteristic findings.
  
  
  METHODS
  We present the unusual case of a dichorionic twin pregnancy in 31 weeks of gestation with one affected fetus, showing already intrauterine a bilaterally enlarged kidney and absence of renal venous flow. Additionally, the fetus showed signs of circulatory compromise and fetal distress, while dichorionic male co-twin was healthy. The postnatal thrombophilia investigations revealed a heterozygous factor V Leiden mutation.
  
  
  CONCLUSIONS
  Fetal renal vein thrombosis may occur bilateral and may also involve the inferior vena cava. Rapid deterioration of fetal condition, abnormal fetal Doppler, appearance of hydrops fetalis, may accompany fetal venous thrombosis. By color Doppler flow mapping abnormal arterial and absent venous perfusion of the affected kidney may be demonstrated in addition.
authors.affiliation: Department of Obstetrics and Prenatal Medicine, University of Bonn, Sigmund-Freud Str 25, 53105, Bonn, Germany, sarah.weber@ukb.uni-bonn.de.
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Weber
authors.forename: Andreas
authors.initials: A
authors.lastname: Müller
authors.forename: Annegret
authors.initials: A
authors.lastname: Geipel
authors.forename: Christoph
authors.initials: C
authors.lastname: Berg
authors.forename: Ulrich
authors.initials: U
authors.lastname: Gembruch
mesh_terms: D000328:Adult; D005165:Factor V / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening; D006801:Humans; D007668:Kidney / Q000002:abnormalities / Q000000981:diagnostic imaging; D008297:Male; D009154:Mutation; D011247:Pregnancy; D059285:Pregnancy, Twin; D012082:Renal Veins / Q000000981:diagnostic imaging*; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000235:genetics
chemical_list: C095381:factor V Leiden; D005165:Factor V