Small black impurities in the urine in late pregnancy may be the result of placental abruption, premature rupture of membranes, etc. You need to lie down in time for fertility preservation treatment and prepare for delivery if necessary. If there is a case of placental abruption, bleeding will occur at the placenta, and if the amount of bleeding is small, it will be mixed in the urine and appear as black material, at this time, you should seek medical treatment in time for fertility preservation treatment, and if the bleeding persists, you need to be prepared to give birth at any time. If there is premature rupture of membranes, meconium may be mixed in the amniotic fluid with the urine outflow, at this time will be shown as a black impurity, you should pay attention to the timely lying down, to prevent the amniotic fluid outflow is too much leading to fetal hypoxia. Pregnant women during pregnancy should pay attention to do a good job of prenatal checkups, actively listen to the advice of professional doctors to do a good job of comprehensive care and health care, pay attention to more rest, at the same time, should relax, to avoid tension, anxiety. If there are abnormalities in late pregnancy, it is recommended to go to the hospital in a timely manner, under the guidance of the doctor to take a reasonable program of treatment.