Haemoglobinopathies in pregnancy

It is Friday afternoon antenatal clinic. A 28-year-old woman from a Vietnamese background books at 10 weeks. Her haemoglobin is 108 g/L, MCV 76 fL, ferritin 65 micrograms per L. If you start her on iron, you treat a thalassaemia trait and risk iron overload; if you miss the carrier state, you fail to offer her partner screening and a one-in-four risk of Hb Barts hydrops fetalis. The fellowship question on haemoglobinopathies is almost always a question about screening both partners and managing sickle cell disease safely.^[1][11]

Overview and definition

Haemoglobinopathies are inherited disorders of globin chain synthesis. Two families matter in obstetrics:^[4]

• Thalassaemia — reduced (or absent) globin chain production. Alpha-thalassaemia is gene-deletion based (chromosome 16, four genes); beta-thalassaemia is point-mutation based (chromosome 11). Severity scales with the number of affected genes.
• Sickle cell disease — HbS polymerises under deoxygenation, causing haemolysis, vaso-occlusion and infarction. Genotypes include HbSS (most severe), HbSC, and sickle beta-thalassaemia.

The trait vs major distinction is the most exam-examined sentence in this topic. Trait is a carrier state with implications; major is a disease with obstetric, transfusion and thrombotic consequences. Knowing which your patient has determines everything that follows.^[1][3]

References13ShowHide

1. [1]Oteng-Ntim E, Pavord S, Howard R, et al. Management of sickle cell disease in pregnancy. A British Society for Haematology Guideline Br J Haematol, 2021.PMID 34409598
2. [2]Oteng-Ntim E, Meeks D, Seed PT, Webster L, Howard J, Doyle P, Chappell LC Adverse maternal and perinatal outcomes in pregnant women with sickle cell disease: systematic review and meta-analysis Blood, 2015.PMID 25800049
3. [3]Chou ST, Alsawas M, Fasano RM, Field JJ, Hendrickson JE, Howard J, Kameka M, Kwiatkowski JL, Pirenne F, Shi PA, Stowell SR, Thein SL, Westhoff CM, Wong TE, Akl EA American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support Blood Adv, 2020.PMID 31985807
4. [4]Taher AT, Iolascon A, Matar CF, Bou-Fakhredin R, de Franceschi L, Cappellini MD, Barcellini W, Russo R, Andolfo I, Tyan P, Gulbis B, Aydinok Y, Anagnou NP, Bencaiova GA, Tamary H, Martinez PA, Forni G, Vindigni R Recommendations for Pregnancy in Rare Inherited Anemias HemaSphere, 2020.PMID 32885142
5. [5]Boulet SL, Okoroh EM, Azonobi I, Grant A, Craig Hooper C Sickle cell disease in pregnancy: maternal complications in a Medicaid-enrolled population Matern Child Health J, 2013.PMID 23315242
6. [6]Chase AR, Sohal M, Howard J, Laher R, McCarthy A, Layton DM, Oteng-Ntim E Pregnancy outcomes in sickle cell disease: a retrospective cohort study from two tertiary centres in the UK Obstet Med, 2010.PMID 27579072
7. [7]Howard RJ, Lillis C, Tuck SM Contraceptives, counselling, and pregnancy in women with sickle cell disease BMJ, 1993.PMID 8343632
8. [8]Cardosa D, Ridout A, Nanda S, Howard J, Robinson SE, Oteng-Ntim E Maternal sickle cell disease and twin pregnancy: a case series and review of the literature Hematology, 2019.PMID 30345909
9. [9]American College of Obstetricians and Gynecologists Anemia in Pregnancy: ACOG Practice Bulletin, Number 233 Obstet Gynecol, 2021.PMID 34293770
10. [10]Camaschella C Iron deficiency Blood, 2019.PMID 30401704
11. [11]Saffi M, Howard N Exploring the Effectiveness of Mandatory Premarital Screening and Genetic Counselling Programmes for β-Thalassaemia in the Middle East: A Scoping Review Public Health Genomics, 2015.PMID 26045079
12. [12]Chan YM, Chan OK, Cheng YKY, Leung TY, Lao TTH, Sahota DS Acceptance towards giving birth to a child with beta-thalassemia major - A prospective study Taiwan J Obstet Gynecol, 2017.PMID 29037546
13. [13]Berbara TMBL, Morais NS, Saraiva DA, Corcino CM, Schtscherbyna A, Moreira KL, Teixeira PFDS, Vaisman M Selective case finding versus universal screening for detecting hypothyroidism in the first trimester of pregnancy Arch Endocrinol Metab, 2020.PMID 32236307