The Rh factor can cause problems with pregnancy if the mother is not treated

During routine prenatal bloodwork, our Grapevine and Fort Worth ObGyns check your blood for the Rh factor to see if you are Rh negative or positive. If, like approximately 85% of the population, you are Rh positive, nothing further needs to be done. However, if the test shows that you are Rh negative, which means your red blood cells do not contain the hereditary protein, then you will need another blood test 28 weeks into the pregnancy.

The Rh factor can cause Rh incompatibility during pregnancy

When a mother does not have the Rh factor, but her fetus is Rh positive, Rh incompatibility can occur. Usually during delivery, but also under other circumstances, the fetus’ Rh positive blood may come into contact with the mother’s Rh negative blood, causing the mother to develop antibodies, which makes a mother Rh sensitized.

If a woman is not treated for Rh sensitization, the Rh antibodies she developed, either during her first pregnancy, or even during an ectopic pregnancy, miscarriage or induced abortion, could attack her fetus’ blood and destroy its red blood cells, causing a serious condition called hemolytic anemia.

If you are Rh negative, we will conduct an antibody screen at 28 weeks

If we discover that your blood lacks the Rh factor and you are Rh negative, our Grapevine and Fort Worth ObGyns will schedule an antibody screen at 28 weeks. This test indicates whether or not you are Rh sensitized. To prevent Rh sensitization, we will give you an injection of Rh immunoglobulin, made from screened, donated blood. This injection is given to non-Rh sensitized women to target existing Rh positive cells already in the blood stream and to prevent the production of Rh antibodies. This protection is why it’s so important for women to know whether or not they have the Rh factor.

The injection is also given within 72 hours after you give birth to an Rh-positive infant, as well as after an ectopic pregnancy, induced abortion or miscarriage. It also may be given after chorionic villus sampling or amniocentesis because blood from the placenta may come in contact with the mother’s blood at these times, too.

What if I am Rh sensitized?

It is rare for patients to be Rh sensitized if they have received regular prenatal care, but if it happens, we need to constantly monitor the fetus for problems such as anemia. This could lead to early delivery or fetal blood transfusion.

The Rh factor is just one of many issues our Grapevine and Fort Worth ObGyns monitor during pregnancy to ensure that mother and baby experience the healthiest possible pregnancy and delivery. Contact us to learn more.