This document explores the Rhesus (Rh) factor, its biological significance, and its implications in medicine.
The Rhesus (Rh) factor is a protein (antigen) found on the surface of red blood cells (RBCs) in some people.
The Rh factor was discovered in 1940 by Karl Landsteiner and Alexander Wiener during experiments on rhesus monkeys.
| Rh Type | Description |
|---|---|
| Rh⁺ (Positive) | Red blood cells have Rh antigen |
| Rh⁻ (Negative) | Red blood cells lack Rh antigen |
It occurs when: - Mother is Rh⁻ - Father is Rh⁺ - Baby is Rh⁺
During childbirth or miscarriage, the mother’s blood may mix with the baby’s blood. The mother produces anti-Rh antibodies. In future pregnancies, these antibodies can destroy the baby’s red blood cells.
Haemolytic Disease of the Newborn (HDN): Leads to anaemia, jaundice, or death of the baby if untreated.
Rh⁻ mothers are given an injection called Anti-D (Rh immunoglobulin). This prevents the formation of anti-Rh antibodies.
| ABO System | Rh System |
|---|---|
| Groups: A, B, AB, O | Groups: Rh⁺ and Rh⁻ |
| Discovered in 1901 | Discovered in 1940 |
| Antibodies occur naturally | Antibodies form after exposure |