Sickle Cell Anaemia with Pregnancy

Sickle cell anaemia with pregnancy is homozygous HbSS disease, with chronic haemolytic anaemia, in a pregnant woman. Baseline haemoglobin is 6 to 9 g/dL and falls further as plasma volume rises in pregnancy. It is the most severe form of sickle cell disease and carries a high risk of crisis, severe anaemia, preeclampsia, infection and maternal and fetal death.

• Maternal mortality is higher than in healthy women.
• Fetal loss, growth restriction and preterm birth are common.
• Folic acid and early treatment of infection are the foundation of care.

Women have pallor, mild jaundice, fatigue, bone pain and recurrent infections, with splenic atrophy in adults. Examine pulse, blood pressure, heart murmurs, liver and kidneys.

• Haemoglobin 6 to 9 g/dL at baseline.
• Flow murmurs from anaemia.
• Differential diagnosis: iron deficiency anaemia, malaria, HbSC disease, HbS beta thalassaemia, megaloblastic anaemia, haemolytic anaemia of other cause, HIV related anaemia.
• Complications: crisis, acute chest syndrome, aplastic crisis, severe anaemia, heart failure, preeclampsia, abruption, preterm birth, fetal growth restriction, stillbirth, postpartum infection.

The approach is to confirm HbSS and measure baseline function.

• Haemoglobin electrophoresis or HPLC (HbS above 80 percent, HbA absent).
• Full blood count and film, reticulocytes, ferritin, serum folate, urea, creatinine, liver enzymes, urine protein to creatinine ratio, HIV, hepatitis B and syphilis tests.
• Blood group with red cell antibody screen; echocardiography if there is a murmur, breathlessness or oedema.
• Ultrasound for dating, growth at 24, 28, 32 and 36 weeks; umbilical artery Doppler if growth is poor.

The principle is folic acid, infection prevention, anaemia monitoring and planned delivery.

• Supportive: hydration; avoid cold and exertion; avoid smoking and alcohol; sleep under insecticide treated net; antenatal clinic every 2 weeks and weekly after 32 weeks.
• Pharmacological: folic acid 5 mg oral daily; aspirin 75 to 150 mg oral at night from 12 weeks to 36 weeks; enoxaparin 40 mg subcutaneous daily during admission and for 6 weeks after delivery; sulfadoxine-pyrimethamine 3 tablets (500 mg and 25 mg each) oral monthly from 13 weeks with folic acid reduced to 400 micrograms daily, or proguanil 100 mg oral daily with folic acid 5 mg; amoxicillin 500 mg oral 8-hourly for 7 days for bacteriuria; ceftriaxone 2 g IV daily for fever; ferrous sulphate 200 mg oral 8-hourly only if ferritin is below 30 micrograms/L; oxytocin 10 IU IM at delivery.
• Procedures: simple transfusion for haemoglobin below 6 g/dL, or a fall of 2 g/dL, heart failure or crisis; prophylactic top up transfusion for twin pregnancy or previous severe complications; induction at 38 to 40 weeks; caesarean section for obstetric reasons.
• Special groups: women with red cell antibodies need phenotype matched blood; newborns have haemoglobin electrophoresis at birth and penicillin V 62.5 mg oral 12-hourly from 2 months if sickle disease is confirmed.
• Red flags: pain crisis, fever above 38 degrees Celsius, chest pain, cough, breathlessness, headache, haemoglobin below 6 g/dL, reduced fetal movements.
• Follow-up: haemoglobin every 2 to 4 weeks; urine culture monthly; growth scans every 4 weeks from 24 weeks; contraception with depot medroxyprogesterone 150 mg IM every 13 weeks or a copper intrauterine device; genetic counselling.