Oxford Handbook of Midwifery by Janet Medforth, Sue Battersby, Maggie Evans, Beverley Marsh, Angela Walker Page A

thalassaemia
Normal
( aa/ – –) or ( a – /a –)
 1 thalassaemia
Small red blood cells
(– a/ – –)
Hb H disease
Moderate anaemia
(– –/– –)
Hydrops fetalis
Not compatible with life
Screening for thalassaemia
As with sickle cell anaemia, antenatal screening should be offered to all pregnant women as recommended. 1
A routine FBC will identify women with hypochromic, microcytic anaemia. Haemoglobin electrophoresis will then identify the underlying haemoglobinopathy.
Knowing the carrier state of each parent allows counselling about the risks to the fetus of being a carrier or having the disease.
Haemoglobinopathy screening is carried out on newborns as part of the neonatal blood spot test.
THALASSAEMIA
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Impact of maternal thalassaemia major on pregnancy
Depends on the degree of chronic anaemia and the oxygen deprivation that results from this.
If the woman cannot adequately meet her own oxygen needs the fetus becomes progressively hypoxic.
Fetal survival may be threatened with spontaneous abortion, intrauterine growth restriction, preterm birth, or intrauterine death.
Women who are carriers (A- and B-thalassaemia trait) may be only mildly anaemic and require only supportive care.
Management of thalassaemia major during pregnancy
Specialist medical and obstetric supervision is required.
Blood transfusion therapy continues.
Use of iron chelation therapy is not without risk and needs to be individualized.
Iron deposition in the pancreas and thyroid increases the risk of the woman developing diabetes, so a glucose tolerance test would be indicated.
Blood transfusion while vital increases the risk of cardiac failure, which in turn, increases the risk of maternal mortality by as much as 50%.
Women who are asymptomatic before pregnancy may find the added stresses of pregnancy can cause deterioration of their health status. The more severe the syndrome, the more significant are the consequences for the woman and fetus.
1 National Institute for Health and Clinical Excellence (2008). Antenatal care: Routine care for the healthy pregnant mother. Clinical guideline 62. London: NICE. Available at: M www.nice.org. uk/cg62.
CHAPTER 4 Antenatal care
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Antenatal examination
The purpose of the antenatal examination depends on the length of gesta- tion at which it takes place.
NICE has published guidelines for the routine care of women who are experiencing a healthy, low-risk pregnancy. 1 The recommended number of scheduled appointments is determined by parity and the function of the appointment. For the primigravida with an uncomplicated pregnancy, 10 visits are adequate; and for the parous woman with an uncomplicated pregnancy, seven visits should be adequate.
Throughout the antenatal period, be alert to the signs and symptoms of conditions that affect the health of the mother and fetus, such as pre- eclampsia, diabetes, and domestic abuse.
After the first appointment or booking visit, use the next visit to review, discuss, and document the results of all the screening tests undertaken earlier, and to identify women who need additional care.
Arrange further investigations for a woman with a haemoglobin level of less than 11g/dL and offer iron supplementation.
• At each visit, measure the blood pressure and test the urine for protein.
At each visit, be prepared to ask questions, give information and discuss issues about the woman’s physical and emotional/psychological well- being; and to use the available time to provide education, supported by antenatal classes and written information.
After 20 weeks, measure and plot the symphysis–fundal height to detect small or large for dates pregnancies.
If requested by the mother, auscultate the fetal heart sounds by hand- held ultrasound.
Offer anti-D prophylaxis to Rhesus-negative women at 28 and 34 weeks’ gestation.
Offer a second screening for anaemia and atypical red cell antibodies at 28 weeks’ gestation. Investigate a haemoglobin level of less than 10.5g/ dL