1. Sickle cell disease
-refers to a group of disorders arising from defective genes that produce abnormal Hb molecules (HbS).
-Defective genes produce abnormal haemoglobin α- or β-chains resulting in HbS.
- homozygous sickle cell anaemia/sickle cell disease (HbSS) and heterozygous sickle cell trait (HbAS).
-SCAthe erythrocytes are fragile, with a short life span of 17 days, compared with 120 days in a healthy individual.
-The erythrocytes have a characteristic crescent, or sickle, shape which blocks up the capillaries.

2. -This predisposes to clot formation in the capillaries.
-Diagnosis is by Hb electrophoresis, and identification of the abnormal sickle-shaped cells on a blood film.
-A bone marrow biopsy may also be required.
- Treatment outside of pregnancy includes:
1- the administration of 1 mg/day oral folic acid tablets
2- prophylactic penicillin
3- thromboprophylaxis, iron chelation agents
4- exchange blood transfusion.

3. A sickle cell crisis
arises when the sickle cells form clots in the capillaries resulting in deoxygenation, and tissue death as a result of infarction.
-The crisis presents acutely with :
-severe pain
-breathlessness
-pallor
- fever
- joint swelling
- pain,
- general weakness

4. -The crisis exacerbated, by :
-infection
-cold temperature
-dehydration
- stress
- exercise.
*Other complications are :
1-chronic anaemia
2- bone marrow suppression
3- thromboembolic disease
4- cardiac failure due to chronic hypoxaemia
5- aplastic anaemia,
6- sudden death

5. *pre-conception care -the folic acid should be increased to 5 mg/day
- iron chelation discontinued 3–6 months prior to conception due to possible teratogenicity
-If the woman has pulmonary hypertension, pregnancy is contraindicated due to the 50% maternal mortality risk
-In pregnancy the woman's care should be shared between the obstetric and haematology team, with appointments being made for every 2–4 weeks to assess maternal and fetal wellbeing.

6. - The woman presenting with sickle cell anaemia is at risk of experiencing a sickle cell crisis secondary to:
- infection
-pre-eclampsia
-miscarriage
- IUGR
-stillbirth

7. - diagnosis -FBC, -blood group -antibody screen - reticulocyte count
- serum ferritin levels
- HIV and hepatitis screening (because of history of blood transfusions)
-renal and liver function tests.
-Folic acid should be increased to 5 mg/day if not done so pre-conceptually, and iron supplements only given if indicated by serum ferritin results.
- Antibiotic therapy may need to be continued.

8. -In the third trimester serial growth scans should be undertaken (
-In labour:
- an epidural is recommended for pain relief as opiates should be avoided.
- Blood should be taken for FBC, group and save.
-Graduated compression stockings are used to reduce the risk of VTE
- the woman should be kept warm and hydrated to prevent any sickle cell crisis from occurring.

9. -Oxygen therapy might be required to maintain adequate oxygenation and improve cardiac function.
-Prophylactic antibiotics may be considered to reduce infection.
-A prolonged labour should be avoided and active management or caesarean section may be advised depending on the woman's health
-Where there is IUGR, continuous fetal monitoring would also be recommended

10. -During the postnatal period, the midwife should be vigilant in her observations as the woman is at increased risk of sickle cell crisis, thromboembolism and postpartum haemorrhage.
-Prophylactic antibiotics and thromboprophylaxis should continue
- early mobilization is encouraged.
- observations should be undertaken, including respiration rate.

11. -The woman should be advised about subsequent pregnancies and the risk they carry in increasing the frequency of crises.
-It is therefore important that the woman uses appropriate contraception in order to maximize her health as intrauterine contraceptive devices (IUCDs) are relatively contraindicated due to the risk of infection.
- Neonatal screening of babies must be undertaken by obtaining a capillary or venous sample of blood at birth. -Those with a positive result require a follow-up appointment and electrophoresis at 6 weeks, including prophylactic antibiotic cover from 3 months of age

12. -In sickle cell trait (HbAS) the individual is usually asymptomatic.
- Although the sickle screening test is positive
- the blood appears normal.
- In pregnancy the woman may present with mild anaemia and so 5 mg/day folic acid is recommended to improve erythropoiesis.