Introduction

Sickle cell disease is an inherited disease that affects the haemoglobin, a protein present in red blood cells which are responsible for carrying oxygen through the body. Sickle cell disease follows an autosomal recessive inheritance which means that a person must inherit two defective copies of the defective gene from each parent to acquire the disease. It is most prevalent among people of African, Hispanic, Middle eastern, Asian, Indian and Mediterranean descent.¹

Sickle cell disease is of particular importance in pregnancy as it increases the risks of maternal and fetal complications and requires special management and care.

Definition and causes of SCD

SCD is caused exclusively by inheriting the sickle cell gene. A child acquires sickle cell disease if two of his biological parents are carriers or affected. Subsequently, a person who acquired only one defective gene from only one parent is said to be a carrier of the disease and does not manifest it. However, if a carrier person has a child with another carrier person, there will be an increased chance that the child gets affected by the disease. For parents who are both carriers of the defective gene, there is a 25% chance of having an offspring with sickle cell disease.²

Types of SCD 

There are several types of sickle cell disease, they are determined by the specific hemoglobin gene inherited from each parent. The most common types of SCD are:

Hemoglobin (SS)

This is the most common and most severe form and also known as sickle cell anemia. From each parent, the affected individual will inherit a sickle cell gene. These people generally develop symptoms from early childhood.

Hemoglobin (SC)

In this disease, the affected person acquires one sickle cell gene and one hemoglobin C gene. This is the second most common type of sickle cell disease; it is milder than HbSS but still can present with serious complications.

Hemoglobin (HbS) beta thalassemia

In this form, the affected individual acquires one sickle cell gene from one parent and one gene for beta thalassemia from the other parent. It is usually milder than Hemoglobin SC.

Impact of SCD on health and daily life

SCD is a chronic condition and may significantly affect an individual’s health and daily life. The impacts varies widely among individuals and can include:

• Painful events

One of the main characteristics of SCD is the painful events also called vaso-occlusive crises. It is caused by blockade of blood circulation by the sickled red blood cells. Severe pain will result from deprivation of body tissues from oxygen. This can affect any part of the body but often occurs in the back and chest and extremities of the body.³

• Anaemia

Chronic anaemia leads to generalised fatigue and minimises physical exercise tolerance. Sickle cell disease patients often require blood transfusions.

• Increased susceptibility to infections

People with sickle cell disease are known to have infections especially when they are young.Therefore, they should require attentive preventive care and management.⁴

• Organ damage

Due to the abnormal function of the sickle cells and their incapacity to flow through the small vessels to deliver oxygen to organs properly all major organs can be affected including the liver, lung, heart, kidneys, eyes, bones and gallbladder.⁵ 

The effects of sickle cell disease are numerous and can affect to a great extent the quality of life of a person. From disrupting daily activities, work and education, the chronicity of this disease can lead to mental impact in the form of depression and anxiety and even to financial stress to the affected person and his family due to high medical costs for treatment and management. 

Challenges in pregnancy with SCD

Increased risks for the mother

Pregnancy in women with SCD presents significant challenges requiring multidisciplinary approaches and due to its potential complications it is considered a high risk pregnancy. Some challenges that pregnant women with sickle cell disease face include:

• Increase pain crises: the vasoocclusive painful crises are increased in frequency and severity in pregnancy which may lead to more frequent hospitalisation and administration of painkillers.
• Anaemia: During pregnancy there is a physiological anaemia due to the increased level of blood plasma. This normal physiological condition will be exacerbated in pregnant women with sickle cell disease which may require more frequent blood transfusion.
• Pre-eclampsia: A condition in which there is elevated blood pressure, presence of protein in urine and possible multisystem organ affection. Preeclampsia is a serious condition and requires early and prompt management. It can lead to critical maternal and fetal complications.
• Venous thromboembolism: It is a condition that occurs when there are blood clots in the veins. Pregnancy by itself is considered a hypercoagulable state, and sickle cell disease increases the risks of clot formation due to obstruction of blood circulation by the sickled red blood cells.

Risks for the fetus

The fetus of a pregnant woman with SCD can be greatly affected by the condition:

• Intrauterine growth restriction and low birth weight 

In this case, the baby does not grow to the desired growth and weight and is small for its gestational age. This baby is subjected to perinatal morbidity and mortality.

• Preterm labor and delivery

There is also a higher rate of babies delivered before their due date with sickle cell diseased women. It is worth noting that sometimes due to maternal complications, healthcare professionals may induce labor early to relieve the mother.

• Congenital SCD

If the father of the baby has hemoglobin SS or is a carrier, there is a high chance that the baby will get the disease or become a carrier.

Managing Pregnancy with SCD

Preconception counseling and  planning 

Managing pregnancy with SCD requires a multidisciplinary approach consisting of obstetricians, hematologist, skilled midwife and careful monitoring, recognising the risk factors for an acute attack of sickle cell crisis and proper prevention.

•  Preconception counseling: Genetic testing for both partners to know their Hb status is important especially in individuals and communities with high prevalence of sickle cell disease. If one partner or both are affected or carrier of an abnormal gene, the couple should be counseling regarding the possibility of having a carrier or affected offspring.
• Optimisation of health prior to pregnancy: Optimizing health prior to pregnancy in patients with SCD can prevent lots of complications. It should start with lifestyle modification like quitting alcohol and smoking and managing stress. Acquiring a satisfactory nutritional status by taking prenatal vitamins. It is also recommended that women receive antenatal vaccinations recommended antenatally in addition to pneumococcal and meningococcal vaccines.

Monitoring and regular health checks

Monitoring and regular health checks are of utmost importance for a positive outcome of a pregnancy with sickle cell disease. 

• More frequent antenatal visits than for standard pregnancy will be more increased during the third trimester of pregnancy.
• More frequent blood, urine tests to detect early infections and treat appropriately. Patients will also have oxygen saturation checks to ensure adequate oxygenation and blood pressure measurements to ensure blood pressure is within normal limits.
• Mental health checks to screen for depression and anxiety as they can be exacerbated by chronic illness.

Delivery and Postpartum Care

Delivery and postpartum care of women with SCD necessitate particular awareness. Delivery is often considered earlier to reduce risks. Normal vaginal delivery is encouraged but cesarean section may be considered if complications arise. During delivery pain management with epidural analgesia is recommended to reduce stress together with adequate hydration and oxygenation. Cross-matched blood should always be available, and continuous fetal monitoring for favorable outcomes.

Postpartum is the period after delivery, it is generally considered the first 6 weeks following delivery. It is of particular importance in women with sickle cell disease as they are prone to get a sickle cell crisis after delivery. Management consists of fair hydration, good control of pain and early mobilisation of the patient.⁶ They are at increased risk of getting deep venous thrombosis and are often given thromboprophylaxis to prevent DVT. Breastfeeding is encouraged and appropriate contraception methods should be discussed with the patient before leaving the hospital.

Conclusion

SCD in pregnancy is complex and is considered a high risk pregnancy with increased rates of complications to the mother and fetus and requires a multidisciplinary approach to achieve a favourable delivery with a healthy mother and child. Management includes preconception optimisation with genetics screening and counseling, careful monitoring of pregnancy and early prevention of risk factors and early management of complications. Although pregnancy with SCD presents many challenges, with proper care and management, women can have successful pregnancies, deliveries and healthy babies.

Empowering women affected with sickle cell disease with knowledge about their condition and management is paramount for optimal outcome. Management of SCD is individualised for each patient and generally involves prevention of crises and symptomatic treatment and psychosocial support. More research in SCD is to be encouraged for improvement of care and hopefully cure of this genetic disease.