Prenatal renal vein thrombosis in dichorionic twin pregnancy.

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.