Genotype & Blood Group
Compatibility Checker

Full pre-marriage health compatibility check — sickle cell genotype, blood group, and Rh factor. Know before you say "I do".

Always Free AA / AS / SS / AC / SC Rh Factor Check Punnett Square
Sickle Cell Genotype Check
Compatibility Result
Blood Group Compatibility
Pre-Marriage Health Checklist

WHO and health ministries across Africa recommend pre-marital health screening to prevent avoidable disease transmission and plan for healthy families.

These tests are recommended — not mandatory in most countries. Results do not legally prevent marriage but help couples make informed decisions and plan medical care.
Frequently Asked Questions
What does genotype AA, AS, SS mean?

Your haemoglobin genotype determines whether you carry the sickle cell gene. AA means you have two normal haemoglobin genes. AS means you are a carrier (sickle cell trait) — you are healthy but carry one sickle gene. SS means you have Sickle Cell Disease — both genes are abnormal. People with SS often experience painful crises, anaemia, and organ damage from childhood.

Can two AS people marry?

Two AS partners have a 25% chance with each pregnancy of having an SS child (sickle cell disease), 50% chance of AS (carrier like the parents), and 25% chance of AA (normal). Many AS-AS couples marry successfully and seek prenatal diagnosis or use IVF with pre-implantation genetic diagnosis (PGD) to have healthy children. The decision is personal and medical counselling is strongly recommended.

What is Rh factor and why does it matter?

Rh factor is a protein on red blood cells. Being Rh positive (+) means you have it; Rh negative (-) means you don't. When an Rh-negative mother carries an Rh-positive baby, her immune system may produce antibodies against the baby's blood. This is called Rh incompatibility. The first pregnancy is usually safe, but subsequent pregnancies can be affected. A simple injection (anti-D immunoglobulin) given during pregnancy prevents complications — this is why knowing your Rh status is vital.

What is haemoglobin C (AC, SC, CC)?

Haemoglobin C is another variant of haemoglobin, more common in West Africa. AC carriers are typically healthy. CC causes mild anaemia. SC disease (one S gene + one C gene) causes a form of sickle cell disease — usually milder than SS but still serious. An AS + AC couple has a 25% chance of an SC child with each pregnancy.

How common is sickle cell in Africa?

Africa bears 80% of the global sickle cell disease burden. In Nigeria, approximately 24% of the population are AS carriers. Ghana has a carrier rate of ~25%. In Uganda and East Africa, the rate is lower (~13%). About 150,000–200,000 babies are born with sickle cell disease in Africa every year — more than anywhere else in the world.

About This Tool

Why Genotype Matters

Sickle Cell Disease (SCD) is the most common genetic disorder in Africa. Unlike most genetic diseases, it is entirely preventable with awareness and pre-marital screening.

Africa Stats

  • Nigeria: ~24% population are AS carriers
  • Ghana: ~25% carrier rate
  • 150,000+ SCD babies born in Africa yearly
  • Only 50% of SCD children in Africa reach age 5
⚠️ Medical Disclaimer: This tool provides general health information only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical decisions. In an emergency, contact your local emergency services.
Genotype Quick Reference
AA + AA
Safe
AA + AS
Safe (50% carrier)
AA + SS
All AS (caution)
AS + AC
25% SC risk
AS + AS
25% SS risk
AS + SS
50% SS risk
SS + SS
100% SS — Avoid

Genotype Compatibility in Africa: What You Need to Know

Sickle cell disease (SCD) is caused by inheriting two abnormal haemoglobin genes — one from each parent. In sub-Saharan Africa, where sickle cell carrier rates can reach 25-40% in some populations, pre-marital genotype testing is one of the most important steps a couple can take before starting a family.

The most critical combination to avoid is AS + AS. Each pregnancy carries a 25% chance of producing an SS child who will have sickle cell disease. With SS + SS couples, every child will have the disease. Many African countries, including Nigeria, Ghana, and Cameroon, have launched public health campaigns encouraging genotype testing before marriage.

Beyond sickle cell, haemoglobin C variants (AC, CC, SC) are common in Ghana and Burkina Faso. SC disease, while sometimes milder than SS, still causes significant health problems. Haemoglobin AC couples have a 25% chance of CC offspring, and AS + AC couples have a 25% chance of SC disease offspring.

Rh factor incompatibility is a separate but equally important consideration. In Africa, approximately 6-8% of the population is Rh negative. When an Rh-negative mother and Rh-positive father conceive, the mother may develop antibodies (sensitisation) that attack subsequent Rh-positive pregnancies. This is preventable with anti-D immunoglobulin treatment during and after pregnancy.

Deep Review - 27 April 2026

Use Genotype Compatibility Checker in a safer care workflow

These tools help turn technical health information into plain-language questions. They should make the user better prepared, not more confident than their clinician.

Use It To Decide

  • Which result or compatibility issue needs a doctor, lab, or genetic counsellor
  • Which family or partner conversation needs documented evidence
  • Which records to bring to the next appointment

Better Workflow

  • Use verified lab reports or confirmed genotype/blood group records
  • Write down questions before acting on the result
  • Keep personal health data private and avoid posting raw reports publicly

Do Not Ignore

  • A result marked critical, very high, or very low
  • Symptoms that do not match a reassuring calculator output
  • Marriage, pregnancy, or transfusion decisions without professional counselling
Official Context
Related AfroTools
Complete package upgrade

Genotype Compatibility Checker: save, export, and continue the workflow

This app now has its own benchmarked improvement layer, dashboard handoff, email-gated PDF plan, and a route into the Labs and compatibility pack workflow.

Competitor feature checked

Premarital genotype counselling tools: Compatibility checks must push lab confirmation and counselling before decisions.

Implemented here: Added labs workflow plan, red-flag copy, and dashboard/PDF actions.

CDC sickle cell disease

Dashboard and PDF actions

  • Save this health plan to the dashboard workspace on this device.
  • Unlock a PDF version through the Health email gate for follow-up and visit prep.
  • Signed-in sessions attempt account workspace sync when the shared workspace API is available.

Continue in Labs and compatibility pack