What Your Rh Factor Means

Women typically have no trouble finding something to worry about during pregnancy. This is not an insult – it is the fact that women have so much love for the tiny life (or lives) growing within them…yet they are unable to do much outside of eating well and staying healthy. Many things during pregnancy are out of an expectant mother’s control: the gender of her child, the position of the baby, and the mother’s Rh factor.

Many women have never even heard of the Rh factor until they are expecting for the first time. The Rh factor is a type of protein on the surface of red blood cells. When you come in for your first prenatal appointment, your blood will be drawn for a series of lab tests. One of these tests is to determine whether you are Rh-positive or Rh-negative.

Your Rh factor is inherited, and you have no control over being Rh-positive or Rh-negative. 85% of people are Rh-positive, and this factor will not affect a woman’s pregnancy. However, women who are Rh-negative (that is, they do not have the Rh-factor within their blood) may experience what is called “Rh incompatibility.” If the father is Rh-positive and the mother is Rh-negative, the growing baby can inherit the Rh gene from the father – posing a risk to the pregnancy and baby.

If an Rh-negative mother’s blood comes into contact with blood from her Rh-positive fetus, the mother’s body will create antibodies against the baby’s blood. These antibodies will attack the baby’s blood as if it were a harmful substance, which can lead to miscarriage, hemolytic anemia, brain damage, or even death of a newborn baby.

The blood screen done during your first prenatal appointment will show if you are Rh-positive or Rh-negative. If you are Rh-negative, you will be given a shot of Rh immunoglobulin (Rhlg) around the 28th week of pregnancy. This shot will target any Rh-positive cells in the bloodstream to prevent the production of Rh antibodies. Once the baby is delivered, the baby’s blood will be immediately checked for his/her Rh-factor. If the baby has a Rh-positive factor, another shot of Rhlg will be given.

While the Rh-factor can seem like a scary factor that is completely out of your control, at Marietta OB-GYN Affiliates, P.A. we are here to provide you with the highest standard in prenatal care. Your prenatal visits are a vital part of a healthy pregnancy – they can help to save your baby’s life and your own. Please call today to schedule your appointment.