The Rhesus (Rh) factor is a protein that can be found on the surface of red blood cells. Most individuals have the Rh factor and are considered Rh-positive, while those without it are Rh-negative. While the Rh factor itself does not cause infertility, it can play a critical role in pregnancy complications that may impact future fertility or pregnancy outcomes.
Rh incompatibility occurs when an Rh-negative woman carries an Rh-positive baby. If the baby’s blood enters the mother's bloodstream, her immune system may view the Rh-positive cells as foreign and start producing antibodies—this is called Rh sensitization.
This sensitization can also occur after a previous miscarriage, abortion, or pregnancy involving an Rh-positive partner. Once sensitized, the mother's body remains alert and can attack future Rh-positive pregnancies, treating the baby as a threat and potentially causing miscarriage or other complications.
In a first pregnancy, Rh incompatibility usually doesn’t cause problems because antibody production takes time. However, if sensitization has already occurred, future pregnancies with Rh-positive babies are at risk. The mother’s antibodies can cross the placenta and destroy the baby’s red blood cells, leading to hemolytic disease of the newborn (HDN). HDN can cause anemia, jaundice, heart failure, or more severe outcomes.
Thankfully, Rh incompatibility is preventable. Rh-negative women are routinely given Rh immunoglobulin (RhIg), commonly known as RhoGAM, during the 28th week of pregnancy and again after birth if the baby is Rh-positive. This medication prevents the mother’s immune system from reacting to the baby’s Rh-positive blood.
Rh factor issues do not directly cause infertility. However, if left unmanaged, they can lead to pregnancy loss and complications, affecting a woman’s emotional and physical health. Awareness and timely treatment are essential to support successful pregnancies.
Rh testing is a standard part of prenatal care. Identifying the Rh status of both the mother and the baby early in pregnancy helps doctors provide appropriate interventions and prevent sensitization.