Sickle cell disease, trait and family planning

What it is

An inherited condition affecting haemoglobin, the oxygen-carrying part of red blood cells. Sickle cell disease and sickle cell trait are different. Knowing both partners' haemoglobin genotypes helps them understand the chances for their children.

When to seek urgent care

With sickle cell disease, seek urgent assessment for fever or feeling acutely unwell. Go immediately for chest pain, difficulty breathing, sudden weakness or speech trouble, severe headache, marked paleness, a swollen abdomen, uncontrolled pain, or a painful erection lasting 4 hours. Follow the emergency thresholds in your care plan and do not delay if the person looks seriously unwell.

How it shows

Sickle cell disease may cause anaemia, painful episodes, swollen hands or feet, jaundice and repeated infections. Symptoms often begin in infancy. People with sickle cell trait usually have no symptoms of the disease.

What to do

Arrange haemoglobin testing and follow-up with a clinician. Before pregnancy, both partners can ask for testing and genetic counselling. People with the disease need continuing care and a written plan for pain and emergencies.

AA, AS and SS: what the letters mean

Haemoglobin carries oxygen inside red blood cells. Each biological parent passes on one haemoglobin gene copy. A represents usual adult haemoglobin; S represents a sickle haemoglobin variant. These are haemoglobin genotypes, not ABO blood groups or rhesus (Rh) types.

AA: no S variant in this simplified example. AS: sickle cell trait, with one A and one S; most people are well, but can pass S to a child. SS: sickle cell anaemia, a form of sickle cell disease. Trait does not turn into SS later in life. Rare trait-related problems can occur with severe dehydration, low oxygen or extreme exertion.

Other variants exist. SC and sickle beta-thalassaemia can also cause sickle cell disease. The AA/AS/SS explorer below cannot interpret C, beta-thalassaemia or an uncertain laboratory report.

Planning a family together

For AS with AS, each pregnancy has a 25% chance of AA, 50% of AS and 25% of SS. This does not mean exactly one of four children will have SS. A previous child's result does not change the next child's chance. The same principle applies whichever partner has either genotype.

Both partners should have reliable haemoglobin testing and discuss the actual reports with a clinician or genetic counsellor. Blood grouping for transfusion does not replace haemoglobin testing. Screening may need confirmatory tests; mention any recent transfusion because it can affect interpretation.

There is no medical test that decides whether two people should marry. Counselling should explain the chances respectfully and support the couple's own choices. Depending on wishes and availability, discussions may include natural conception, prenatal testing, IVF with embryo testing, donor eggs or sperm, adoption, or choosing not to have children. These options have different costs and limitations and none should be imposed.

Living well with sickle cell disease

Sickle cells can block small blood vessels and break down early, causing painful episodes and anaemia. Children can have painful swollen hands or feet; infections, chest complications and stroke need rapid care. Symptoms and severity vary widely.

Regular care can reduce complications. Ask about vaccinations, infection prevention, hydroxyurea, a written pain plan and appropriate stroke screening for children. Transfusions and specialised treatments help selected patients. Stay hydrated and avoid extreme heat or cold; do not assume every new symptom is an ordinary pain episode.

Arrange newborn testing early when a child may be at risk. Pregnancy with sickle cell disease needs coordinated specialist and maternity care. A genotype does not predict a person's lifespan; timely, continuing care makes a substantial difference.

Sources

1. About sickle cell disease · CDC · Public domain text (CDC reuse terms)
2. What is sickle cell trait? · CDC · Public domain text (CDC reuse terms)
3. Sickle cell disease: diagnosis · NHLBI, National Institutes of Health · Linked clinical reference; no source material reproduced
4. Living with sickle cell disease · NHLBI, National Institutes of Health · Linked clinical reference; no source material reproduced
5. Sickle cell disease: pregnancy and reproduction · NHLBI, National Institutes of Health · Linked clinical reference; no source material reproduced