Delivery and Birth

Delivery and Birth

Antibodies are not an automatic c-section – you can have a vaginal birth even if your baby has HDFN. It is very helpful to keep a notebook and write down all your questions (and the doctor’s answers) about birth and the hospital’s processes. This will also help your support person to know what the plan is and what needs to be done. Make sure they will have antigen negative blood ready for you and baby before delivery. If you’ve got anti-K, baby needs K negative blood. If he needs a transfusion, you don’t want to wait several hours and risk brain damage while they find blood. You will want to read about the testing that needs to be done after birth. Cord blood needs to be drawn, and it is helpful if a support person can remember to ask to have that drawn. Don’t forget to get a copy of the Personal Care Record to help you keep track of all the test results for baby.

Multiple medical articles recommend delivery at 37-38 weeks if you have antibodies.

Yes, even if your titers are low.
Even if your MCA scans are good.
Even if you haven’t needed IUTs.

American College of Obstetricians and Gynecologists

Committee Opinion 818 – “At risk pregnancy not requiring intrauterine transfusion – early term – 37 0/7 – 38 6/7 weeks of gestation”. “Pregnancy requiring intrauterine transfusion – Late preterm or early term – individualized”

Practice Bulletin 192 – “Standard treatment is to prolong the pregnancy until the fetus reaches a gestational age necessary for survival. If the history and antenatal studies indicate only mild fetal hemolysis, it is reasonable to proceed with delivery by induction of labor at 37–38 weeks of gestation.”

Royal College of Obstetricians and Gynaecologists

Green-top Guideline 65 – “In general, for red cell antibodies that could cause fetal anaemia but which have been stable throughout pregnancy, delivery should take place between 37 and 38 weeks of gestation. If an IUT has not been required but antibody levels are rising then consideration for earlier delivery may be necessary. If an IUT has been required, delivery will need to be timed to ensure that the fetus is not significantly anaemic at birth. This will depend on the gestation that the last IUT was performed as well as the estimated rate of drop of fetalhaemoglobin/haematocrit.”

Society for Maternal-Fetal Medicine(SMFM) Clinical Guideline #8

Clinical Guideline #8 – “Expert opinion suggests planning delivery at 37-38 weeks of gestation based on balancing the risk of stillbirth, the consequences of fetal anemia, and the risks of another fetal blood sampling procedure/intrauterine transfusion, against the risks of prematurity and the additional morbidity of anemia and hyperbilirubinemia prior to term delivery.”

Management of Pregnancy Complicated by RhD Alloimmunization

Kenneth J Moise Jr, MD

“MCA-PSV ≤1.5 MoMs for gestational age — An MCA-PSV ≤1.5 MoMs for gestational age is consistent with absence of moderate to severe anemia. If MCA-PSV remains at this level, we schedule delivery at 37+0 to 38+6 weeks of gestation, consistent with Society for Maternal-Fetal Medicine and American College of Obstetricians and Gynecologists guidelines”

“Intrauterine transfusion is generally limited to pregnancies <35 weeks of gestation because after 35 weeks, intrauterine transfusion is considered riskier than delivery followed by postnatal transfusion therapy. At ≥35 weeks of gestation we would deliver a fetus with MCA-PSV >1.5 MoMs for gestational age”

Inductions can occur at any number of weeks, but are typically 32-37 weeks. Generally the doctors will try to time the last IUT around 35 weeks. The goal is to get to 35 weeks for delivery. At 35 weeks the survival rate is over 95%, and there are less risks to delivery and transfusing a baby vs the risks from an intrauterine transfusion. Women delivery at 35-37 weeks have usually had at least one IUT or they may have had higher numbers on the MCA scans. If you get a MoM of 1.5 at or after 35 weeks, they will just deliver baby instead of trying to do an IUT. Most women with antibodies deliver at 37-38 weeks. The ACOG Practice Bulletin 192 says that it is reasonable to proceed with the induction of labor at 37-38 weeks if signs of mild hemolysis is present. “Mild hemolysis” isn’t defined in the document, but an MoM of 1.3 or higher is considered mild anemia 15. A rise in titers, even if they do not reach critical may signify an affected baby and could be considered mild hemolysis. Multiple medical organizations recommend induction at 37-38 weeks even if things with the baby look great, but why do we induce?

Inducing a woman with antibodies early takes many things into account. MCA scans aren’t as accurate after 37 weeks. The risk for false positives gets higher. It is also harder to get a clear reading on baby. As baby turns head down and settles by the pelvis, it can be very difficult to get the correct angle on the top of the skull for the MCA scan. Using angle correction can lead to an anemic baby appearing to be not anemic. If we don’t have MCA scans to monitor baby, then we are left with blood work and non stress tests. 

Titers aren’t necessary after they’ve hit critical and you’ve begun scans. Once critical titer has been reached, you should always be treated as if you have a critical titer, even if it goes down. If titers take 1-2 weeks to come back, then you are already getting old and outdated information in the last 4 weeks of pregnancy. Things can change quickly these last weeks (that’s why weekly titers are recommended) because the pregnant woman’s blood volume increases dramatically. Most of this is plasma, which is where the antibodies are found. Baby’s blood volume increases as well. This means more fetal blood, and more of it getting into mom’s system where the antibodies can find it. This can cause her to make more antibodies that can then cross the placenta and attack baby’s blood cells. Additionally some antigens aren’t fully developed until a few weeks before or after delivery. The c antigen is one of them. This means that a woman’s body may be seeing more of the antigens than before and either make more antibodies or there will now be more antigens on the blood cells for more of the antibodies to bind to (more chances to cause anemia). If titers haven’t been drawn regularly, then there would be no way to know if they had increased in the last couple of weeks, so the information learned from drawing them again on a woman who has already been receiving scans would be minimal. Titers are not an indication of how baby will do after birth. 

Non stress tests are great for checking on baby and most alloimmunized women begin to receive them weekly at 32 weeks gestation. They see how baby is responding to contractions, but unfortunately they do not show anemia. They will show a faster heart rate, but some babies have higher heart rates normally. The NST will show a slower heart rate. Babies with HDFN can compensate for the anemia. This makes it so that it is possible for baby to still pass an NST and still be anemic. If anemia shows up on an NST, it will be at or past the time when a transfusion should have happened. 

Some women notice decreased movement as a sign that baby is anemic. If you notice decreased movement, always get it checked out and notify your care provider and/or labor and delivery if you notice decreased movement. Do talk with your doctor about how to do kick counts and make sure to do them at the same time of the day when baby is awake so that your decreased movement isn’t just baby sleeping. It is normal for baby to move less as you get further along because there’s not as much room in the uterus as before. Decreased movement at 36 weeks vs 30 weeks can be normal, but it is worth getting checked out. Some moms have said that their baby had a flurry of kicking activity when they were anemic before passing away. It’s also normal for baby to be kicking a lot if mom has had sweets or something cold to eat/drink. Movement is no guarantee of how baby is doing, but sometimes it’s all there is to go on. 

The survival rate of babies born at 35 weeks is over 99%. The rate of infant death for those born 34-36 weeks was 7.1 out of 1000, that is 0.0071%, which means that 99.9929% of babies born between 34 and 36 weeks survive. At 32-33 weeks, the mortality rate was 16.2 per 1000, so 0.016%, but 99.98% survived 55. The rate of loss from an IUT is 1.8%. For IUTs performed after 2001, the survival rate is 97%. This is why doctors induce and treat after birth instead of continuing to transfuse and reach a higher gestation 56

It may be helpful to wait to have the delivery discussion in detail until you are approaching the 35 week mark. A lot can change between where you are now, and later. When the time comes, print off articles that show that induction is the regular course for women with alloimmunization. The photos above may be some of them. It is helpful to highlight the articles and let the doctor read them so that you can have a discussion about the timing of delivery. There are a variety of methods used for induction. Ask your doctor for additional resources, what the procedures are, and any other questions you may have.


My daughter’s MoM was 1.5 at 37 weeks. I was scheduled for induction 2 weeks later at 39 weeks with no additional scans or rechecks. It was such a stressful time for me – I wondered if my baby would even be healthy enough for a vaginal delivery or if she would die before birth. I wish I had this information about the timing of delivery back then. I would have pushed harder for these guidelines to be followed.

Monique K.


Antibodies are not an automatic c-section. You can have a vaginal birth.

Even if your baby has HDFN you can still have a vaginal birth. For us, it meant there was an entire team of people in the delivery room (9+), including a midwife, obstetrician, neonatologist, some people from the special care nursery, lab tech, and several nurses. Talk with your doctor and see what they recommend, and who they recommend be present. Blood needs to be drawn at birth, so have someone, such as your support person, make certain that it is done. Since it is not commonly done everywhere, it can be easy for delivery personnel to forget to do the immediate draw.


Cesarean Section

Cesarean sections, C-sections for short, can happen at any time for babies with HDFN. Talk with your doctor about a contingency plan for if you need a C-section, who will be present, what will happen with the baby, will you get to hold him/her, etc. Delayed cord clamping is also possible with a C-section. Keep in mind that a C-section is still major surgery and you will probably feel out of sorts for a few days. It’s a good idea to have some extra help with moving around, caring for the baby (and other children), housework, etc. Having a notebook or a copy of the personal care record can help your support person to know what tests and appointments need to be made for your baby.

This baby is anemic and pale

Special Care & NICU

Regardless of how you deliver your baby, an infant born to an alloimmunized mother shows clinical signs based on the severity of the disease. While some babies show mild or no signs of HDFN at birth, others are have signs of moderate to severe disease right away. The typical diagnostic findings are jaundice, pallor, enlarged liver and/or spleen (hepatosplenomegaly), and fetal hydrops in severe cases. The jaundice typically manifests at birth or in the first 24 hours after birth with rapidly rising unconjugated bilirubin level. Occasionally, conjugated hyperbilirubinemia is present because of placental or hepatic dysfunction in those infants with severe hemolytic disease 5.

For this reason, you should talk to your doctor about delivering in, or near, a hospital with a NICU or special care team equipped to take care of the baby. One of the worst things is to be stuck at one hospital while your baby is sent to another hospital (possibly hours away), without you. We have 2 hospitals in my town, one with a NICU, and one without. I chose to deliver at the one without the NICU, but I was informed beforehand that if my baby needed a transfusion or special care, the baby would be transferred, but I may not be (depending on how busy the hospital was).

These are pictures and descriptions of what care for an alloimmunized pregnancy and a baby with HDFN looks like. The photos might seem scary at first, but remember, knowledge is power. It’s much better to have an idea of what things might look like, than to be shocked when your medical team first does something. It should also be reassuring the number of babies who have gone through this before and are now perfectly healthy, normal children. All of the babies below were in the NICU. Not all babies born with HDFN are sent to the NICU.

Delayed Cord Clamping

Delayed cord clamping is a practice where the umbilical cord is not immediately clamped or cut after birth. The delay time can range from a few minutes up to half an hour. Generally the cord will be limp, pale, and no longer pulsing when clamped. Up to 1/3 of the baby’s blood is in the placenta at the time of birth. Delayed clamping allows the baby to get his extra blood back from the placenta. Keep in mind though that with the blood comes the antibodies too.

Our MFM recommended it. Our cases of HDFN was not severe, and there was greater benefit to our baby getting the extra blood than the risk from the extra antibodies. He did have a drop in his hemoglobin levels (3 whole points), but because he had his extra blood, it was not low enough to need a transfusion. Some MFM recommend against it. In severe cases of HDFN, your antibodies will do more harm than the good the extra blood will do. In this case, it is preferable to give the baby a transfusion with clean donor blood than to give him blood with more antibodies. A study done in 2016 showed that infants who received delayed cord clamping were less likely to need an exchange transfusion. They also went longer before needing their first transfusion after birth. “This study highlights a significant benefit of DCC in anemia secondary to red blood cell alloimmunization with a resulting decreased postnatal exchange transfusion needs, an improvement in the hemoglobin level at birth and longer delay between birth and first transfusion with no severe hyperbilirubinemia.” 57

Talk with your doctor and decide what is best for you and your baby. Regardless of if you choose to do delayed cord clamping or not, it is very important that cord blood be drawn to be tested for hemoglobin, bilirubin, and the direct coombs test.

Learn more about care after birth.

%d bloggers like this: