Planning for any baby can feel overwhelming, especially if your baby is at risk of maternal alloimmunization or hemolytic disease of the fetus and newborn (HDFN).
After I found out my baby was at risk, I wanted to make sure I had all the information available to me to make an informed decision for both myself and my infant.
Preparing for an early delivery
If your baby is at risk of HDFN, it is not uncommon to deliver before 40 weeks. According to both the American College of Obstetricians and Gynecologists, and the Society For Maternal-Fetal Medicine, maternal alloimmunization is listed as a reason to induce labor. The recommended time for this is 37 to 38 weeks, during a time that the baby grows very rapidly–about a half-pound a week.
With this kind of growth, both the maternal blood volume and fetal blood volume increase, and alloantibody activity tends to “amp up” somewhat, particularly with the three most severe types of alloantibodies: anti-c, anti-D (Rh disease) and anti-K1 (anti-Kell).
Maternal alloantibodies, like many other types of antibodies, are developed to attack and destroy fetal red blood cells containing their incompatible red cell antigens. For example, with an anti-c diagnosis, a baby positive for the “c” antigen is vulnerable to maternal anti-c. Hemolytic anemia, which can be very aggressive, occurs when these fetal red blood cells are destroyed, although this does not happen with every alloimmunized pregnancy.
Learn more about HDFN causes and risk factors
Understanding the different types of maternal alloantibodies
So, how many types of maternal alloantibodies and antigens are there? There are over 50 different types of red blood cell antigens (proteins), from several different blood groups and alloantibodies which are considered “clinically significant” and have been implicated in cases of HDFN. Some cases are mild; others are more severe in how they can affect a baby. In cases of maternal alloimmunization, your baby inherits a specific type of red blood cell antigen from the father.
During pregnancy, alloantibodies can cross the placenta and cause HDFN by destroying the fetal red cells. In some cases, this can be fatal. In my own personal experience, it helps to understand certain biological characteristics of your alloantibody types. Some women develop more than one type. Educating yourself on your type can be very beneficial, especially if your health care provider has limited experience with maternal alloimmunization.
In addition, some fetal red cell antigens finish maturing quite late during a pregnancy, which means the maternal alloantibodies can cause HDFN seemingly very aggressively and suddenly. Anti-c is a good example of this; it is not uncommon for an anti-c titer and antibody production to suddenly increase in the last weeks.
Focusing on harm reduction and prevention
After around weeks 35 to 36, I recommend a preventative strategy, especially with subsequent alloimmunized pregnancies, or in the case of the tjree most severe alloantibody types (c, D and K1) to increase the frequency of checking titers from biweekly to weekly. A three-or-four-fold increase in titers during a short time, such as one week, can be an indication of late antibody activity and potential HDFN. In my opinion, this is something to take notice of and communicate to your doctor.
When you’re discussing your options with your doctor, try not to feel too intimidated to ask questions –you and your baby’s health are your first priority, and you are your baby’s voice. An ideal doctor-patient dynamic is one with strong, consistent communication, where the patient does not feel like they are under the care of an authority figure; instead they are a team with a shared goal.
Perhaps one of the most important things to remember about HDFN is that the effects can be prevented. As a mom with anti-Kell, I highly recommend educating yourself on the necessary tests and monitoring, both during pregnancy and the neonatal period. Know what to advocate for, to feel most confident and comfortable with the situation. If it would make you more comfortable, ask to arrange a tour of your local NICU, and don’t be afraid to ask questions about NICU schedules, routines or procedures.
If you are being hospitalized and preterm delivery is a possibility, ask to speak with a pediatrician, neonatologist or even a pediatric hematologist Though not all babies from alloimmunized pregnancies will be diagnosed with HDFN, babies with severe HDFN are commonly cared for in level “3” NICUs, while babies with less severe hemolytic disease may be cared for in a slightly lower level of care, a level “2” NICU.
One of my biggest takeaways from my own experience with anti-Kell is that, as parents, we do the best we can with the medical knowledge we have at the time we need to make decisions about our babies’ health care. You can navigate this, and you are absolutely your baby’s best voice and advocate.
Sign up here to get the latest news, perspectives, and information about HDFN sent directly to your inbox. Registration is free and only takes a minute.
