Congratulations!

Congratulations on your baby! All life is special and deserves to be celebrated. Antibodies can be a scary thing, but with a little help, everyone can understand them. Let's get started. To better understand this page, read about Prenatal Testing and Prenatal Interventions

Prenatal Complications

Fetal Anemia

Fetal Maternal Hemorrhage

Hemolytic Disease of the Newborn

Ascites

Fetal Hydrops


 

Prenatal Complications

Fetal Anemia

What is it?

Fetal anemia is when the baby is anemic (not enough blood). If the baby is too anemic, a blood transfusion is needed.


How is it found?

You can find out if baby is anemic by having an MCA scan and looking at the numbers from that, or from taking a sample of the baby's blood (in utero), and checking the hemoglobin level. With an MCA scan, you will get PSV values. Ask for them if they aren't given, or look at the screen during the scan. These PSV values are then plugged into a formula to find your MoM number. You can get a great calculator here: http://www.perinatology.com/calculators/MCA.htm

A MoM of 1 is normal. 1.5 is generally considered anemic.


The chart below uses PSV values and gestational ages.

Slopes for peak systolic velocity in middle cerebral artery (MCA) for normal fetuses (dotted line), mildly anemic fetuses (thin line), and severely anemia fetuses (thick line). (5)

This chart shows with the MoM values.
MCA-PSV (cm/s) versus gestational age. Lines indicate MoM values and anemia range. MoMs between 1.29 and 1.5 can indicate mild anemia. MoM over 1.5 indicates moderate to severe anemia. (15)

An excellent resource can be found at https://www.scotblood.co.uk/media/101703/pregnant_women_with_red_cell_antibodies_record_of_care.pdf

This is a collection of documents you can use to keep track of your own care. Print it out and take it with you to all appointments. It has places to record titers, PSV and MoM values, and more.


After an intrauterine transfusion (IUT) the characteristics of fetal blood are altered because adult red cells are smaller and less rigid and they display an increased tendency for erythrocyte aggregation. Therefore it became pertinent to examine the usefulness of MCA PSV following IUT. But applying a change in the established cutoff level for MCA PSV from 1.50MoM (multiples of the median) in the fetus never transfused to 1.69MoM in previously transfused fetus may be of help. (16)


What is the treatment?

The only treatment for fetal anemia is a transfusion. This can be done by an intrauterine transfusion (IUT) if the baby is too young to be delivered (see the section on Prenatal Intervention: Intrauterine Transfusion for more information), or with immediately delivery and transfusion after birth. IUTs are repeated every time baby shows signs of anemia, but usually last for about 2-3 weeks.


What is the best outcome?

Two of the best outcomes involve baby not being anemic enough to need treatment, or making it to delivery with the help of IUTs. Just because you make it to delivery though, does not mean you're out of the woods. ISO babies are at risk of developing late onset anemia from 3 – 12 weeks old, so it is important to have your baby's hemoglobin levels checked until they are at least 12 weeks old. Some babies need checked longer, especially if they have had IUTs. In this case, you may be assigned a neonatologist, or hematologist who will follow your baby closely.


What is the worst outcome?

Untreated fetal anemia is almost always fatal. Even with treatment, it is still possible for the baby to die.

Fetal Maternal Hemorrhage (FMH)

What is it?

Fetal Maternal Hemorrhage (FMH) is when the baby's blood comes out into the mother's bloodstream. This can be a big problem, especially for ISO, because the more of the baby's blood that the mother's body sees, the more antibodies are made. It can cause a jump in titers or additional stress for baby. It can also cause fetal anemia since the blood has left the baby and entered the mother.


How is it found?

Symptoms are subtle and nonspecific. Decreased fetal movement is the only symptom known without additional testing. The Kleihauer–Betke test (KBT for short) measures the amount of fetal blood in mom's bloodstream. FMH can also be diagnosed by flow cytometry, using anti-fetal hemoglobin antibodies (anti-HbF). (17)


What is the treatment?

Treatment options include immediate C-section delivery if near term (compromised placenta may not stand up to labor), or possibly an IUT.


What is the best outcome?

In patients who are not yet sensitized to anti-D, Rhogam will be administered. For all others, if not enough blood has been lost to cause anemia, monitoring is all that is needed.


What is the worst outcome?

If anemia needing treatment is detected, an IUT or delivery with transfusion will occur. If not detected, FMH can cause fetal death. FMH accounts for nearly 14% of unexplained fetal deaths and 3% of all fetal deaths.


Additional Information

FMH has been demonstrated to occur in as many as 75% of pregnancies, with the frequency increasing as gestation advances and with most cases occurring during delivery. If transplacental passage of fetal erythrocytes is suspected, the rosette screening test is used to determine the presence of a fetomaternal hemorrhage. When a large hemorrhage is suspected, the Kleihauer-Betke test is used to quantify the volume of hemorrhage so that an appropriate dose of anti-D IgG can be administered. Hemorrhage volumes sufficient to cause alloimmunization are produced in 15-50% of births. This volume of fetal blood, which, in more than 50% of intrapartum cases can be as small as 0.1 mL and in rare cases can exceed 30 mL, varies depending on the degree of maternal immune response. (17)

As many as 30% of Rh D–negative individuals have been shown to not become alloimmunized, even when challenged with large volumes of Rh D–positive blood. (17)


Hemolytic Disease of the Newborn (HDN)

What is it?

Hemolytic Disease of the Newborn (HDN) is the technical term for what is happening with the baby. Heme = blood, lysis = destruction. It's literally the destruction of the baby's blood cells.


How is it found?

HDN is found through the additional monitoring all mom's with ISO should have. It will be seen with things like rising MoM values, rising titers (not always accurate, MoM should always be relied upon first), worsening biophysical profile, decreasing hemoglobin levels, and evidence of hydrops on the ultrasound.

Indicators for severe hemolytic disease of the newborn (HDN) include mothers who have had previous children with hemolytic disease, rising maternal antibody titers, rising amniotic fluid bilirubin concentration, and ultrasonographic evidence of fetal hydrops (eg, ascites, edema, pleural and pericardial effusions, worsening biophysical profile, decreasing hemoglobin [Hb] levels).(5)


What is the treatment?

Mild hemolytic disease accounts for 50% of newborns with positive direct antibody test results. Most of these newborns are not anemic (cord hemoglobin [Hb] >14 g/dL) and have minimal hemolysis (cord bilirubin < 4 mg/dL). Apart from early phototherapy, they require no transfusions. However, these newborns are at risk of developing severe late anemia by 3-6 weeks of life. Therefore, monitoring their Hb levels after hospital discharge is important.5

Moderate hemolytic disease accounts for approximately 25% of affected neonates. Moderate hemolytic disease of newborn is characterized by moderate anemia and increased cord bilirubin levels. These infants are not clinically jaundiced at birth but rapidly develop unconjugated hyperbilirubinemia in the first 24 hours of life. Peripheral smear shows numerous nucleated RBCs, decreased platelets, and, occasionally, a large number of immature granulocytes. These newborns often have hepatosplenomegaly and are at risk of developing bilirubin encephalopathy without adequate treatment. Early exchange transfusion with type-O Rh-negative fresh RBCs with intensive phototherapy is usually required. Use of IVIG in doses of 0.5-1 g/kg in a single or multiple dose regimen have been able to effectively reduce need for exchange transfusion. (5)

Severe hemolytic disease accounts for the remaining 25% of the alloimmunized newborns who are either stillborn or hydropic at birth. The fetal hydrops is predominantly caused by a capillary leak syndrome due to tissue hypoxia, hypoalbuminemia secondary to hepatic dysfunction, and high-output cardiac failure from anemia. About half of these fetuses become hydropic before 34 weeks' gestation and need intensive monitoring and management of alloimmunized gestation as described earlier. Mild hydrops involving ascites reverses with IVTs in only 88% of cases with improved survival but severe hydrops causing scalp edema and severe ascites and pleural effusions reverse in 39% of cases and are associated with poor survival. (5)


What is the best outcome?

With proper treatment, baby can make it to delivery. Depending on the intensity of HDN, there will be different care needed after birth.


What is the worst outcome?

Untreated HDN is almost always fatal, especially in severe cases. It can cause problems after birth if the infant is not treated properly. Titers are not an accurate indicator of HDN, so additional monitoring must be used to check the severity and effects on baby.

Ascites

What is it?
Ascites is the buildup of fluid in the space between the lining of the abdomen and abdominal organs (18). Ascites is a sign of anemia that has gone on to fetal hydrops and must always be taken seriously with swift treatment.


How is it found?

Ascites is found by ultrasound or when examining the baby after birth.


What is the treatment?

Ascites can be treated before birth with an IUT, or after birth by inserting a tube into the belly to remove large volumes of fluid (called a paracentesis) (18).


What is the best outcome?

With an IUT, ascites can resolve, but the baby must be monitored closely and care must be taken to avoid anemia and hydrops. Repeated IUTs will probably be needed.


What is the worst outcome?

If untreated, ascites can lead to death.

Fetal hydrops

What is it?

Hydrops is the end stage of Hemolytic Disease of the Newborn. It is fetal heart failure.


How is it found?

Signs of hydrops will be detectable on an ultrasound, and may be discovered during your MCA scans. Some women also have decreased movement, or no fetal movement. Signs like hepatomegaly, increased placental thickness, and polyhydramnios often precede the development of hydrops (fetal heart failure) (4).


What is the treatment?

IUT or immediate delivery with exchange transfusion are the only treatments.


What is the best outcome?

After delivery, expect a NICU stay, but with proper care, baby can recover.


What is the worst outcome?

If untreated, it is fatal.