LAB TESTS DONE DURING PREGNANCY WHY ARE TESTS DONE::: A number of lab tests are suggested for all women as part of routine prenatal care.These tests can help find conditions that can increase the risk of complications for you and your fetus. The following lab tests are done early in pregnancy: Complete blood count (CBC) Blood group and Rh typing Urine analysis Hepatitis B and hepatitis Human immunodeficiency virus(HIV) TSH Oral glucose tolerance test(OGTT) PT-INR Hb electophoresis Complete blood count A COMPLETE BLOOD COUNT(CBC) gives information on a number of haematological parameters, but generally in pregnancy the most useful are the haemoglobin, platelets and white blood cell count. Most laboratories will provide pregnancy adjusted reference ranges to enable easier interpretation. VERY LOW OR HIGH HEMOGLOBIN LEVELS are associated with increased fetal risk.Gestational age should be taken into account when assessing haemoglobin, as levels decrease during pregnancy due to haemodilution caused by increased plasma volume. IRON DEFICIENCY ANEMIA is the most frequent haematological concern during pregnancy and is usually characterised by decreased haemoglobin, mean cell volume (MCV) and mean cell haemoglobin (MCH) levels. When iron deficiency is suspected, a measurement of serum ferritin should be used to confirm the diagnosis. CHANGES IN PLATELET LEVELS are frequently seen during pregnancy. A decrease in the platelet count is more common than an increase and is most obvious in women who had low levels prior to becoming pregnant. Platelets usually decrease as a result of haemodilution, and this can become more pronounced as the pregnancy progresses from the second to third trimester.A platelet level of 150 x 109/L or less is abnormally low and should be discussed with a haematologist. Elevated platelets levels during pregnancy are generally a reactive response to the pregnancy and do not usually suggest a clinical problem. However, due to the slightly increased risk of clotting, it would be advisable, when platelet levels are higher than 600 x 109/L, to discuss results with a haematologist. THE TOTAL WHITE CELL COUNT will frequently be elevated in pregnancy due to increased numbers of neutrophils. Neutrophils can also demonstrate a “left shift” (increased number of band neutrophils). However, this neutrophilia is not usually associated with infection or inflammation. to be continued dr nandini shete MD (OB/GYN)