b-Thal Pregnancy Plan (GTG 2014, BSH 2024)
N.B. The BSH2024 guideline is very detailed. I have left out a lot and tried to stick to principles
Abbreviations
TDT = Transfusion-dependent thalassaemia
NTDT = Non-transfusion-dependent thalassaemia
ICT = Iron Chelation Therapy
DFO - Desferrioxamine
DFX - Deferasirox (Exjade)
DFP - Deferiprone
See Hbpathy diagnosis for genetic details. For pregnancy management, the degree of anaemia / iron overload is more relevant than the underlying genetics.
Pre-Conception
Annual clinic review should include discussion of family planning
MDT management throughout entire process
Fertility Unit Assessment
Offer tests including tubal patency, sperm count, hormonal assessment
Discuss adequate contraception until pre-conception health optimised
BSH 2024 guidelines has detailed guidelines for spermatogenesis/ovulation induction
Screen for end organ damage
Aggressive iron chelation preconception reduces / reverses end-organ damage
Sex hormones - Hypogonadotrophic hypogonadism
HbA1c - Diabetes - Aim <43mmol/mol for 3 months prior to conception
PTH - Hypoparathyroidism
TFT – ensure euthyroid
Virology - HIV, Hep B, Hep C
Cardiac – ECG, Echo (LVEF >56%) and T2* MRI (>20ms)
Liver iron – Liver R2 or 2*. Liver iron should be <7mg/g of dry weight
Abdo USS – gallstones, liver cirrhosis, hepatitis
Bone density – Offer bone density scan and ensure vitamin D replaced
Transfusion
Severe anaemia affects fetal growth and maternal health
TDT patients have increased red cell requirements in pregnancy
Confirm extended red cell phenotype / genotype
Vaccination
Hep B vaccine (+ hyposplenic vaccinations if applicable)
HPV for non-immunised patients
Review Medication
Folic acid 5mg daily
VTE risk assessment & treat accordingly
Start aspirin if hyposplenic or platelets >600
Pen V prophylaxis if hyposplenic
Discontinue teratogenic medications (ACEI)
Stop bisphosphonates 3 months prior to conception
Stop DFP / DFX 3 months prior to conception
DFO can be used pre-conception and again from 2nd trimester onward. Take with Vitamin C.
Genetic Counselling
Screen partner
Maternal genotyping
Offer IVF/ICSI with pre-implantation genetic diagnosis to avoid homozygous / compound heterozygous pregnancies if both partners have significant hbpathy.
Other Considerations
Smoking cessation
Psychological assessment / support
Antenatal
At Booking
Review by all members of MDT
VTE Risk assessment
Review pre-conception issues above to ensure all have been addressed
Schedule
Monthly review to 28 weeks then fortnightly
Monthly serum fructosamine (alt. to HbA1c) if diabetes
TFT’s every trimester
Cardiac assessment at 20-24 weeks if TDT
Scans
Offer viability scan at 7-9 weeks
Routine 1st trimester scan at 10-14 weeks
Routine anomaly scan at 20 weeks
Additional monthly growth scans from 24 weeks
Transfusion
If TDT , regular transfusion to maintain pre-transfusion Hb >100g/l
If NTDT, start transfusion if worsening maternal anaemia or growth restriction
Rh and Kell matched units for both TDT and NTDT patients
Thromboprophylaxis
Splenectomy or Plt >600 – Aspirin
Splenectomy & Plt >600 – Aspirin + LMWH
Intrapartum
Inform MDT on admission to delivery unit
If known red cell antibodies or Hb <100g/l, crossmatch blood on admission. Otherwise, G&S only.
Intrapartum fetal heart rate monitoring is recommended (increased risk of fetal distress)
TDT – DFO IV 2g/24hours 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 - DFO is safe. Data lacking for DFX and DFP
Discuss contraceptive options
Oestradiol HRT may support breast feeding for hypogonadal patients
Re-assess iron burden at 3 months