b-Thal Pregnancy Plan (GTG 2014)

 

b-Thal Major – More than 7 transfusion episodes per year

b-Thal Intermedia – 7 or fewer transfusion episodes per year

b-Thal Carrier – do not require transfusion

 

Pre-Conception

 

Annual clinic review should include discussion of family planning

 

Screen for end organ damage

-       Aggressive iron chelation preconception reduces end-organ damage

-       Diabetes common in b-Thal – HbA1c <43 mmol/mol for 3 months prior to conception

-       TFT – ensure euthyroid

-       Cardiac – ECG, Echo and T2* MRI

-       Liver iron – Ferriscan, ideally liver iron should be <7mg per gram of dry weight

-       Abdo USS – gallstones, liver cirrhosis, hepatitis

-       Bone density – Offer bone density scan and ensure vitamin D replaced

 

Vaccination

-       Hep B vaccine (+ Hib and pneumococcus if hyposplenic)

-       Pen V prophylaxis if hyposplenic

 

Review Medication

-       Folic acid 5mg daily

Discontinue teratogenic medications

-       Stop deferiprone and deferasirox 3 months prior to conception

-       Avoid desferrioxamine in 1st trimester. Can be used safely at low doses after 20 weeks

-       Stop bisphosphonates 3 months prior to conception

 

Haemoglobinopathy screening

-       Screen partner

-       Offer IVF/ICSI with pre-implantation genetic diagnosis to avoid homozygous / compound heterozygous pregnancies if both partners have significant hbpathy.

 

Antenatal

 

Schedule

-       Monthly review to 28 weeks then fortnightly

-       Monthly HbA1c if diabetes

-       Cardiac assessment at 28 weeks if b-Thal Major

 

Scans

-       Offer viability scan at 7-9 weeks

-       Routine 1st trimester scan at 11-14 weeks

-       Routine anomaly scan at 20 weeks

-       Additional monthly growth scans from 24 weeks

 

Transfusion

-       If b-Thal Major , regular transfusion to maintain pre-transfusion Hb >100g/l

-       b-Thal Intermedia, start transfusion if worsening maternal anaemia or growth restriction

 

Thromboprophylaxis

-       Splenectomy or Plt >600 – Aspirin

-       Splenectomy & Plt >600 – Aspirin + LMWH

 

Intrapartum

 

If known red cell antibodies, crossmatch blood for delivery in advance

Intrapartum fetal heart rate monitoring is recommended (increased risk of fetal distress)

b-Thal Major – desferrioxamine should be infused during labour

Active management of third stage of labour to reduce blood loss

 

Postpartum

 

Consider as high risk for thrombosis

Breast feeding is safe