Anaemia & Transfusion

Anaemia

Obstetric haematology clinic

Management of anaemia

Labour and delivery of anaemic patients

Red cell blood transfusion

ANAEMIA

Anaemia in pregnancy is defined as a haemoglobin (Hb) level <11 mg/dL, but is managed actively if Hb <10 g/dL. Most women with anaemia are iron deficient, but some have infections (TB, urinary tract infection, HIV, malaria), & a few have genetic disorders (e.g. sickle cell). Consider family & travel history.

Screening & prevention

• All pregnant women must have their Hb measured at the first antenatal visit, & repeated at 32 & 36 weeks
• All pregnant women to receive ferrous sulphate 170 mg (or ferrous fumarate 200 mg) equivalent to 65 mg elemental iron, with folate 5 mg daily orally

Management of anaemia

1.  If Hb <8 g/dL: Start full-dose haematinics – oral ferrous sulphate 200 mg with vitamin C 100 mg, 3 times daily, with folic acid 5 mg daily. Take blood for FBC, retics & morphology, & refer for investigation (Haematology Clinic)
2. If Hb is 8-9.9 g/dL: Management depends on gestational age:
   • Pregnancy ≥36 weeks: Take blood for FBC & refer to Haematology Clinic. May need intravenous iron.
   • Pregnancy 30-35 weeks: Give full-dose haematinics. Recheck Hb in 2 weeks. Hb should improve by at least 1 g/dL. If inadequate improvement, take blood for FBC, retics & morphology, & refer to Haematology Clinic
   • Pregnancy <30 weeks: Give full-dose haematinics. Repeat Hb after 3 weeks: if Hb has not improved by 2 g/dL in 3 weeks, take blood for FBC, reticulocyte indices & morphology, & refer to Haematology Clinic. If Hb is improving, reassess after another 3 weeks
3.  In addition to the above, look for & manage any underlying infection
4. Evaluate symptomatic anaemic patients carefully & consider referral to Haematology Clinic or hospital admission

Women who cannot tolerate iron tablets

Adjust the regimen by, e.g. omitting vitamin C, giving coated tablets, reducing the dose, breaking tablets in half, giving small frequent doses, or children’s syrup. Refer any anaemic woman who still cannot tolerate iron to Haematology Clinic.

Advice to anaemic pregnant women

• Encourage honesty about compliance or intolerance to medication
• Advise consumption of meat, particularly liver (iron) & fresh fruit (vitamin C)
• Discourage pica (consumption of ash, soil, clay, or other non-nutritive items)
• Inform that iron must not be taken at the same time as calcium or antacids
• Discourage excessive consumption of tea or coffee
• Warn about digestive side-effects with iron: advise taking iron during meals

OBSTETRIC HAEMATOLOGY CLINIC

Ideally, patients with haematological disorders in pregnancy should be managed in a special clinic run jointly by an obstetrician & a haematologist.

Problems that should be referred 

• Hb level decreasing on antiretroviral therapy & haematinics
• Anaemia as described above, & anaemia with an Hb <10 g/dL with a mean cell volume (MCV) ≥100 fL
• Thrombocytopaenia other than that caused by pre-eclampsia or acute crises
• Current or previous leukaemia or lymphoma
• Patients who have recently received cancer chemotherapy 
• Other pre-existing haematological disease

MANAGEMENT OF ANAEMIA

Iron deficiency anaemia

• A low MCV & a response to iron suggest iron deficiency
• Treatment is with haematinics at full dose (above)
• Treat any current infection
• Review at intervals according to gestational age, severity of anaemia, & obstetric risk status (above)
• Do baseline FBC, differential count & morphology, then follow up with FBC & reticulocyte parameters. Iron studies are not routinely done 
• With good response, down-refer back to the woman’s local clinic
• Failure to respond to iron therapy requires further investigation & may necessitate the use of intravenous iron
• Blood transfusion is only indicated for cardiac failure, or obstetric reasons.

Megaloblastic anaemia  

• This is more commonly seen in pregnant women from rural areas
• Diagnosis is made by finding a high MCV with megaloblastic changes on peripheral blood smear
• Send blood for red cell folate & serum vitamin B₁₂ levels
• Treatment is folic acid 5 mg orally daily and/or vitamin B₁₂ 1000 µg IM daily for 5 days, then weekly for 4 weeks, then monthly
• Follow up with FBC & reticulocyte indices to assess response
• If response to treatment is satisfactory, refer back to local clinic or hospital antenatal clinic, depending on obstetric risk status
• Failure to respond requires investigation with bone marrow aspiration &/or trephine biopsy

LABOUR & DELIVERY OF ANAEMIC PATIENTS 

Measure Hb on admission, unless a very recent result (<2 weeks) is available

• If Hb ≥10 g/dL, no special measures need to be taken
• If Hb <8.0 g/dL, transfuse 1-2 units of blood if woman is scheduled for emergency caesarean section
• If Hb <6.0 g/dL, transfuse 1-2 units of blood if vaginal delivery anticipated
• The amount of blood transfused depends not only on the Hb level, but on the obstetric risk factors for haemorrhage. It should seldom be necessary to transfuse more than 1 unit of blood for anaemic patients in labour

Postpartum care

• Use oral iron wherever possible to manage postpartum anaemia
• Transfusion is not indicated on the basis of an Hb result alone
• Should blood transfusion be considered, always start with only one unit of blood & assess the symptomatic response
• Ensure patients with chronic haematological problems (e.g. immune thrombocytopaenia or sickle-cell) are on appropriate treatment, & refer them back to their clinic or doctor, with a letter
• On discharge, refer current patients of the obstetric Haematology Clinic back to that clinic, with latest results, including pre-transfusion FBC, reticulocyte indices, & red cell morphology.
• On discharge, refer other (uncomplicated) anaemic patients & those who have been transfused to their local clinic for follow up of the anaemia
• Prescribe full-dose haematinics on discharge, with a plan to continue for 6 months

RED CELL BLOOD TRANSFUSION

• Packed cells are normally used
• Transfuse just enough to reverse symptoms or reach a satisfactory level for delivery or operation. One unit may be sufficient
• Reassess clinical findings & blood requirements before giving multiple transfusions
• If multiple transfusions are anticipated, as in a case of confirmed bone marrow aplasia, give only leucodepleted blood units

No patient with anaemia should be transfused without first doing FBC, reticulocyte indices, red cell morphology & differential count. Patients with uninvestigated anaemia requiring transfusion (not because of an acute bleed), should in addition have blood taken for vitamin B₁₂, red cell folate, & iron studies before transfusion. Any question of marrow aplasia or abnormal morphology must be referred to Haematology Clinic or haematologists.

If giving 2 or more units in normovolaemic patients, give 40 mg furosemide IV with each unit of blood 

Indications for blood transfusion in obstetrics

• Anaemia with cardiac failure
• Anaemia with bone marrow suppression (aplasia)
• Severe symptoms of anaemia - these can be confused with vasovagal symptoms, or tiredness post partum
• Anaemia before caesarean section (Hb <8 g/dL)
• Anaemic women at high risk of haemorrhage e.g. with placenta praevia
• Acute severe haemorrhage
• Anaemic women who need to undergo an immediate general anaesthetic.
• Anaemia with severe sepsis
• Obtain specialist advice before transfusing patients with chronic haemolytic anaemias e.g. sickle cell anaemia – they may need exchange transfusion

NB: Transfuse the patient & not the haemoglobin result.