Blood in urine in labour is diagnostic of :

In obstructed labour, bladder becomes an abdominal organ due to compression of urethra between the presenting pa and symphysis pubis - patient fails to empty the bladder The transverse depression at the junction of superior border of the bladder and distended lower segment is confused with the Bandl's ring The bladder wall get traumatized which may lead to blood stained urine, a common finding in obstructed labour Ref: Datta Obs 9e pg 379.