Midwives focus on Thalassaemia

Antenatal Screening

The government outlined a commitment to establishing a National Antenatal and Neonatal Sickle Cell & Thalassaemia Screening Programme (NHS Plan 2000). A multidisciplinary Committee was convened in 2002.

The NHS Sickle Cell and Thalassaemia (SCT) Screening Programme recommend screening of pregnant women in England by ten weeks of pregnancy, ideally screening should be offered to all childbearing men and women preconception this will enable them to make informed decisions about courtship, marriage and parenting. Women are offered screening for Thalassaemia, based on the routine full blood count indices, whilst screening for sickle cell and other haemoglobinopathies is offered to all women living in high prevalence areas and to minority ethnic (high risk) women in low prevalence areas. Areas of England where there are significant minority ethnic communities are deemed high prevalence whilst areas with few minority ethnic communities are deemed low prevalence.

NHS Trusts: Area prevalence for Sickle Cell and Thalassaemia - https://www.gov.uk/government/publications/nhs-trusts-area-prevalence-for-sickle-cell-and-thalassaemia

Once identified an-at risk woman / couple are offered the option of prenatal diagnosis and if required subsequent termination of an affected pregnancy if selected.

National Institute for Health and Clinical Excellence (2008) Antenatal care: Routine care for the healthy pregnant woman – Clinical Guideline London: NICE

Counselling

London North West Healthcare NHS Trust, is in a high prevalence area, therefore all women booking for confinement of pregnancy at Central Middlesex Hospital, Northwick Park Hospital and in the London borough of Brent and Harrow are offered screening at the first antenatal booking contact. The blood sample is sent to the electrophoresis laboratory, at Central Middlesex Hospital. If a woman is found to have inherited an unusual haemoglobin gene the result is relayed to the specialist midwife/ specialist nurse at the Brent Sickle Cell & Thalassaemia Centre, who will write to the woman inviting her for genetic counselling and testing of the baby’s father.

 

In accordance with national guidelines where a pregnancy is at-risk of producing a child with a clinically significant disease the couple is offered prenatal diagnosis (PND) preferably before twelve weeks of pregnancy.

The type of test offered will depend on how advanced the pregnancy is. Commonly one of two types of tests is offered: Chorionic Villus Sample (CVS) or Amniocentesis, see Prenatal Diagnosis

Clinical Aspects

There are a number of short and long term complications associated with sickle cell disease and beta Thalassaemia although many of these can be minimised with good self and medical management and activities to prevent and treat complications when they occur, see Sickle Cell for Healthcare Professionals.

Fertility, Pregnancy and Childbirth

Men and women with beta thalassaemia trait and any form of intermedia generally reach puberty, have normal fertility, become pregnant and have children. A few with beta thalassaemia intermedia may require hormone therapy to stimulate secondary sexual development, fertility and pregnancy.

Generally people with beta thalassaemia major are infertile if they are poorly managed and lack access to good health care. A significant proportion of these patients worldwide experience pubertal delay and will require some form of medical intervention to establish menarche and fertility (Jensen et al 1995, Savona-Ventura & Bonello 1998, Psihogios et al 2002).

In the UK provided individuals, both men and women, are well managed medically and adhere to all prescribed medical interventions, which include regular blood transfusion and rigorous chelation therapy, the majority are now reaching puberty, are fertile and having a family spontaneously without any hormonal intervention.

Pregnancy needs to be carefully managed by a specialist haematologist who has experience of this client group and an experienced obstetrician (Tuck et al 1998). In the UK Whittington Hospital and University College Hospital in London are well established and recognised as leading specialist Centres in managing this client group and have reported many successes in their patients becoming parents.

Provided the woman has been carefully managed from childhood with regular blood transfusion, has adhered to prescribed chelation therapy and there are no underlying sequela, for example, diabetes and cardiac problems, management of pregnancy involves continued regular blood transfusion and close monitoring of mother and fetus. Labour is usually uneventful and is similar to those of the general population. However, they are often prescribed prophylactic antibiotics post delivery. For more details on the subject suggest Weatherall & Clegg (2001), Steinberg et al (2001).

To date there are no reported cases of people with alpha thalassaemia major surviving into adulthood, therefore there are no reported cases achieving pregnancy. However, there are now several reports of successful intrauterine transfusion and subsequent live births. The long term outcome for these children is as yet unknown. Following birth the child is being managed with regular blood transfusion and chelation therapy. Later in life the child may require hormonal therapy if there is delay in pubertal development or subsequent infertility.

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