Midwives focus on Sickle Cell

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.

The NHS Sickle Cell and Thalassaemia screening programme (2006) recommend screening of pregnant women 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, see Sickle cell and thalassaemia screening: commission and provide. GP surgeries (Thomas et al 2005), family planning clinics, well man and well woman clinics, university and college health centres are best placed to offer preconception information and where appropriate testing as early as possible in pregnancy.

Sickle Cell Trait

Sickle cell trait is a healthy carrier state however it is reported that people with sickle cell trait are less able to concentrate their urine (hyposthenuria) and may be prone to dehydration. Secondly, they are more prone to developing urinary tract infections such as bacteriuria, pyelonephritis and a small proportion may have frank haematuria especially among women during pregnancy, hence the need for strict urinary tract infection screening in this group. Prompt and rigorous treatment with antibiotics is essential in many cases these episodes subside after the baby is born (Embury et al 1994, Serjeant & Serjeant 2001) but a few may need longer term management.

Sickle Cell Disease

Women and to a lesser extent, men with sickle cell disease are potentially vulnerable to complications which may precipitate infertility and in fertile women complications are increase during pregnancy and childbirth (Howard et al 1993, Eboh, van Den Akker 1994, Adams 1996, ). In males, lower semen volume, sperm count, and sperm motility have all been observed (Davis 1988), which may relate to sickling in the testes. There is no evidence that female fertility is affected by sickle cell disease, however Tuck (1985) suggest there is a slight risk but as medical care of these patients have been improving over the years data observed in 1985 had improved Tuck et al (1998) and continues to improve. Pregnancy can pose a greater health challenge and the pregnant woman with sickle cell disease need specialist obstetric and haematology care Oni et al (2002).

Apart from the clinical effects and complications of sickle cell disease from childhood through to adulthood there are additional effects of sickle cell disease on a pregnancy and effects of the pregnancy on a woman’s sickle cell disease (Tuck 1985, Embury et al 1994, Howard et al 1993, Howard 1994, Steinberg et al 2001, Serjeant & Serjeant 2001).

The various complications of pregnancy tend to be exacerbated in women with this a chronic illness and they need extra care and management to avoid a worsening of their illness, potential loss of the fetus or and mother.

Diagram 4 - Clinical Implications and Complications of Sickle Cell Disease in Pregnancy



Maternal Mortality Rate (UK) among women without sickle cell disease is 5 per 1000 Births Maternal Mortality Rate (UK) among women without sickle cell disease 0.06 per 1000 Births.

Management of Ante-natal Period

Pregnant women with sickle cell disease are considered high risk and are therefore managed by a consultant obstetrician in cooperation with the haematologist, and other members of the care team. Taking account of the potential complications during pregnancy the woman’s care will need to be carefully planned and decisions made about frequency of clinic visits, assessments of the woman’s sickle cell disease, management of the pregnancy as well as monitoring of the fetus. (Embury et al 1994, Steinberg et al 2001, Oni et al 2002)

In keeping with national standards, see Sickle cell and thalassaemia screening: commission and provide, the woman’s partner should be offered testing to determine whether the couple are at-risk of having a child with sickle cell disease. If the couple are at-risk the couple should be offered prenatal diagnosis and the option of termination of an affected fetus if they wish. A number of ethical and social issues need to be considered to allow the woman and her partner to make an informed choice with regard to screening, and where relevant prenatal diagnosis and outcome of an affected pregnancy (Marteau 1995, Marteau et al 2001).

During pregnancy there is a low threshold for prescribing antibiotics and any sign of infection is managed promptly and rigorously.

Labour

Normal delivery should be anticipated provided pregnancy has been uncomplicated and uneventful (Eboh &Van Den Akker 1994, Howard et al 1993, Embury et al 1994, Serjeant & Serjeant 2001). Management involves recognising the general problems associated with sickle cell disease including, increased risk of infection, inability to concentrate urine therefore tendency for dehydration, may experience problems with oxygenation. Intravenous hydration and oxygenation is usually prescribed.

Puerperium and Post Natal

Maintain IV hydration for at least 24 hours, and if required oxygenation. All babies in England are routinely offered testing for sickle cell disease at age 5 – 8 days, see Sickle cell and thalassaemia screening: commission and provide, however a normal or carrier result may take four to six weeks to be reported and if the couple are known to be at-risk of having a child with sickle cell disease this waiting for the result is anxiety provoking. In view of this it is recommended that known risk couple’s babies should have diagnostic testing (not screening) as soon as possible after birth, using the heel prick method a small sample should be placed in an EDTA bottle. The result is usually available in a few days and the parent’s anxieties can be allayed.

Mothers should be encouraged to breastfeed unless there is a specific contraindication.

A broad spectrum prophylactic antibiotic is recommended for approximately 5 days post delivery. Due to increased risk of thromboembolism early ambulation is advised and anticoagulation for up to six weeks post delivery.

Contraception

Choices about contraception methods may be more difficult for women with sickle cell disease because the intrauterine contraceptive device may result in an increased susceptibility to heavy painful periods and the contraceptive pill can be unpredictable in its effect in this client group. However Howard et al (1993) suggest that this should not deter offering use of these contraceptives and their benefits are likely to outweigh their dis-benefits.

Several studies have demonstrated that oestrogen has a beneficial effect on the red cell membrane, giving females of reproductive age a marginal advantage over males (Platt et al 1991). Hence the use of inject able contraceptive preparations such as Depo-Provera is popular among women of reproductive age because it is reported to reduce the occurrence of vaso occlusive crisis. Some women have reported an increase in episodes of painful crisis during their menstrual periods.

The teenage years are a time of rapid growth and development, the hormonal changes of pubertal development may contribute to increasing episodes of crisis and pain. The long-term effects of sickle cell disease often begin to emerge during the teenage years and this may be a time of increased episodes of sickle cell crisis, especially in young men. This evidently can have a major impact on education, career and future employment prospects, and social relationships.

For a more in depth coverage of management of pregnancy and labour see Embury et al 1994, Steinberg et al 2001, Serjeant and Serjeant 2001, Oni et al 2002).

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