RH Negative (Rh-) - What does it mean for you?
Your RH status is very important for you and your baby. If you are RH-, then you will probably be advised to have a shot. This article will explain a little about what that shot is, what being RH- is, and why you might want to research things before you consent to the shot.
Are you Rh Negative? A New, Non-Invasive Test lets you discover baby's blood type before birth. More on the RhD Genotyping test.
Determining your blood type
When you get your prenatal workup done, your blood type will be assessed. You'll learn what letter your blood type is (A, B, AB, and O). You will also learn what your Rhesus, or RH, factor is. Your blood can be either RH+, meaning the blood has the RH factor, or RH-, meaning the RH factor is not in your blood.
Sometimes you will hear RH factor referred to as RH (D) positive or RH (D) negative.
There are six RH genes: C, D, E, c, d, and e.
The C, D, and E genes are positive RH genes; meaning there is an RH factor in the blood.
The c, e, and d genes are negative RH genes; meaning there is no RH factor in the blood.
Only the "D" gene has been shown to cause sensitivity issues, so it is the D gene that is of concern during your pregnancy. That is why RH factor is referred to as RH (D) positive or RH (D) negative by some practitioners. You may also hear the shot given to RH- women referred to as Anti-D immunoglobulin.
Why does it matter if I have RH- or RH+ blood?
Bottom line: If you are RH- and your baby is RH+, there could be complications for your baby, or future babies.
If you are RH+, then you do not have to worry, because your body does not mind an RH- fetus. If you are RH- and your baby's father is also RH-, then you probably do not need to worry. However, Natural Birth and Baby Care.com reader Sharon contacted me with this information after she and her husband, both Rh-, had an Rh+ baby:
From much research and meeting with genetics specialists...I discovered that you can have a positive baby, even if you are both negative parents.
In light of this information it would probably be prudent to have your baby's cord blood typed even if both you and your baby's father are Rh-.
If you are RH- and your baby RH+, and your blood mixes with your baby's, it could become sensitized. Your body could begin producing antibodies to the RH+ blood. If these antibodies get to an unborn baby, they can begin killing off the baby's red blood cells. This is called RH disease. It is rare for it to affect a first baby, but if the mother becomes sensitized and produces antibodies to RH+ blood, it could cause problems for future babies. RH disease is very serious; however, recent medical advances allow 90% of babies with RH disease to survive (March of Dimes).
I have RH- blood. What can I do to keep my baby (and future babies) safe?
There is a shot available for women who are RH-. The shot is often called by the brand name Rhogam (BayRho-D is another brand). It is an Anti-D immunoglobulin. The shot is a processed human blood product containing antibodies to the RH factor. Injecting a the small number of RH antibodies into your blood sends them to work on any fetal blood cells in your bloodstream. This causes your body to think that the situation is under control and keeps you from producing antibodies on your own.
The shot was originally given within 72 hours of birth. Now it is common for it to be given routinely during pregnancy around 28 weeks. Some doctors are also giving it routinely at 36 weeks. It is also recommended after any type of "trauma" that could cause maternal and fetal blood to mix. Examples of such trauma are miscarriage, abortion, amniocentesis, CVS, car wreck, falling on your belly, etc.
This sounds great! Why should I think twice about the shot?
The shot is a human blood product. There are some possible side effects to the shot, including possible effects on the immune system of mother and child. The shot is screened for all diseases which it is possible to screen for and the reaction rate is low. Nevertheless, these risks do exist. Some Anti-D immunoglobulin shots are preserved in mercury, which is another concern. There are mercury-free versions available (BayRho and RhoGAM Plus RhoGAM Plus is also latex free.)
The Anti-D shot is only effective within 72 hours of maternal-fetal blood mixing. So even if the injection is given at 28 weeks, it will only help if maternal and fetal blood has mixed 72 hours or less before the injection. The Rhogam manufacturer states that an injection every 12 weeks will maintain a "passive immunity," meaning that theoretically a shot every twelve weeks will protect you in the event of trauma causing your and your baby's blood to mix. They still recommend a new shot at the time of blood mixing if >15mL of exposure has occurred.
Normally during pregnancy, maternal and fetal blood flows side by side at the placenta, but never actually mixes. During the course of normal childbirth, the maternal and fetal blood will not mix. It is usually during childbirth with intervention that the blood mixes. Interventions could be forceps, episiotomy, cord traction (pulling on the umbilical cord to get the placenta out), or cesarean section, among others. During pregnancy, amniocentesis, CVS, hard falls, car accidents, miscarriage, or abortion, among others, could cause maternal and fetal blood to mix.
In a natural childbirth where the third stage of labor is allowed to progress gently (no forcing the placenta to come), it is very rare for the blood of mother and baby to mix. A homebirth with no medical intervention is often the safest way to assure that maternal and fetal blood does not mix.
If the baby is born RH-, there is no danger of the mother becoming sensitized and so Anti-D is not needed.
So what should I do?
Some women choose to get all the Anti-D injections their care providers give routinely for the peace of mind that they get from it.
Other women choose to completely forgo any shots, not wanting to introduce human blood products into their bodies or their baby's body. They also don't want to risk the possible side effects of the shot.
Some women choose not to have the injection done in the prenatal period. After the baby is born, the woman has the baby's blood tested. If the baby is RH+, she has an injection of Anti-D immunoglobulin. It is important that the shot be given within 72 hours after birth, so the baby's blood must be tested immediately. Blood taken from the umbilical cord works perfectly for the test.
Some women opt for the injection either prenatally and postpartum, or only postpartum, but request that a mercury-free version be administered.
Some women decline prenatally but go in for the shot if they've been in an accident or require a medical procedure that could cause mixing of maternal and fetal blood.
Some women choose to have a test done on their own blood, called and Indirect-Coombs. This test will show whether or not the woman's blood has been sensitized to the RH factor. They may have it done before and during pregnancy, so that they know exactly what is happening with their body.
A hard choice for some.
Some women have a hard time deciding what to choose when it comes to their RH status and the shots. They may want to do everything they can to protect future children, but be unsure how effective a shot given routinely in the prenatal period really is. And they may feel uncomfortable having a human blood product injected into their body while they have an unborn baby in the womb.
It is not an easy choice to make. It deserves careful consideration and weighing all the risks and benefits. Speak to your care provider about it.
Some other resources you may wish to peruse (please note only one of these was written by me; I express no agreement or disagreement with the other sources - I provide them for your information):
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