The roles of blood picture, haemoglobinopathy traits, and blood groups determined in routine antenatal tests in the screening for complications in pregnancy.

Routine antenatal tests include haemoglobin measurement, usually with red blood cell indices, white cell and platelet counts, and ABO and Rhesus blood groups, are aimed to screen for iron deficiency anaemia, carriage of haemoglobinopathy traits, and other forms of anaemia or other underlying but undiagnosed conditions. Iron deficiency anaemia has been associated with most of the common pregnancy complications including pre-eclampsia, preterm birth, antepartum and postpartum haemorrhage, low birthweight and small-for-gestational age infants, and impacts long-term neurocognitive and developmental outcomes in the offspring. Increased adverse pregnancy and perinatal outcomes are also found with high haemoglobin, thalassaemia and sickle cell traits, and the non-O blood groups especially group AB. Total white cell, neutrophil, and platelet counts and platelet indices can help to predict gestational diabetes mellitus. Results from these tests can be useful by themselves or used in combination with demographics and biomarkers to enhance the screening for high-risk pregnancies.