Anti D titer test is done on a blood sample to check the level of Anti D Titer level in the blood. It is performed specifically on pregnant women to assess their Rh incompatibility and also to check results of the medications. Women with titer more than 1:4 are usually considered as Rh ill immunized. These titers relate more with the existence of a fatal disease than with the subsequent ones. This test is performed monthly till 20 to 24 weeks of gestation and biweekly after that. If the reports continue to be critical, they can hamper the pregnancy state.