Hemoglobinopathies in Pregnancy

The hemoglobinopathies are red blood cell disorders which result either from the synthesis of structurally abnormal Hb chains (the Hb variants) or from the defective synthesis of Hb chains (the thalassemia syndromes). These inherited genetic disorders are inherited in Mendelian recessive manner so that persons with the carrier or traits are generally healthy. Patients manifesting clinically significant disease may be homozygous for any one condition or can be heterozygous for two or more hemoglobinopathy genes which interact.

The hemoglobinopathies are result of mutation and deletion in and around the globin genes on chromosome 16 and 11.

• There is increased incidence of abortion, intrauterine growth restriction and prematurity. Fetal distress and perinatal mortality is increased, four to six folds.
• Close observation is recommended at 32-34 weeks; obtain pregnant patient's blood cell count, to detect hemoglobin level, infection, and serial ultrasonography to monitor fetal growth.
• Crisis complicates about 35% of pregnancies. Painful crisis during pregnancy should be distinguished from ectopic pregnancy, placental abruption, pyelonephritis, appendicitis, cholecystitis or other serious obstetrical or medical problems that cause pain, anemia or both.
• Anemia is not marked, hemoglobin concentration falls below 7 gm/dl only if there is presence of infection or nutritional deficiency. Folate supplementation is recommended due to quick turnover of erythrocytes. Increased risk of infection is partly due to loss of splenic function. UTI is twice as common in sickle cell trait.
• Bacteriuria and pyelonephritis are also increased which can precipitate red cell destruction; hematuria is present in few cases. Cardiac dysfunction is present in most of the pregnant women. Pre-eclampsia and thrombophlebitis which also increase maternal morbidity and mortality, is estimated to increase by 2.5%. Sickling occurs acutely specially late in pregnancy, labor, delivery and early peurperium. Acute chest syndrome, this is characterized by fever, tachypnea, pleuritic chest pain, leukocytosis and pulmonary infiltrates. It may be caused by pulmonary infections or infarction from intravascular sickling or thrombosis.
• Splenic sequestration, retinopathy, leg ulcers, aseptic necrosis of bone, renal papillary necrosis, stroke leading to premature death are also seen in some cases.

Over all management should take place in combined clinics with experienced hematologists and obstetricians.