Causes of hematuria outside pregnancy are all implicated in hematuria occurring in pregnancy in addition to pregnancy-specific causes such as pre-eclampsia and placenta percreta. When no organic cause is found, hematuria is classed as Idiopathic. Most authorities believe idiopathic hematuria is due to peculiar changes in the urinary tract resulting from mechanical and hormonal factors related to pregnancy. Such hematuria usually begins in late second trimester through the third trimester and resolves after delivery. A case is presented of idiopathic hematuria in a 33-year old mother of 3 whose hematuria resolved at 34 weeks as abruptly as it had started at 18 weeks in pregnancy. Clinical features suggest the cause to be the Nutcracker phenomenon. The need for non-invasive investigations and conservative management is stressed as well as the rarity of such cases resolving before delivery.
Keywords: Hematuria, pregnancy, idiopathic, nutcracker phenomenon