Fetal Thrombocytopenia

Fetal thrombocytopenia is a blood disorder in which a fetus doesn’t have enough platelets.

Platelets, also known as thrombocytes, are blood cells that help form clots to stop or prevent bleeding.

How does thrombocytopenia affect my baby?

A low platelet count increases the risk of bleeding complications in the fetus and the newborn.

Thrombocytopenia can range from mild to severe. Most cases are mild, with symptoms after birth that may include bleeding into the skin (petechiae), bruising after injections, or bleeding after circumcision.

In severe cases, the baby may have internal bleeding during pregnancy or after birth, including bleeding in the brain, known as intracranial hemorrhage (ICH), causing fetal or newborn death or long-term disabilities.

Platelet Alloimmunization and Other Causes

The leading cause of severe thrombocytopenia is platelet alloimmunization, or incompatibility between the mother’s platelets and the father’s platelets. Because one half of a fetus’ genetic makeup comes from the father, it is possible for a fetus to have a different platelet type from the mother. In rare cases, the mother’s immune system reacts as if the fetal platelets are a foreign substance, producing antibodies that can cross through the placenta, attack and destroy the platelets in the baby’s blood. The result can be a low platelet count causing the fetus to have episodes of internal bleeding, in severe cases into the major organs.

Thrombocytopenia caused by platelet alloimmunization goes by several names, including fetomaternal alloimmune thrombocytopenia (FMAIT), fetal and neonatal alloimmune thrombocytopenia, and neonatal alloimmune thrombocytopenia (NAIT).

Other causes of thrombocytopenia include congenital infections, which can decrease platelet production, chromosomal disorders, and autoimmune thrombocytopenia, in which both mother and fetus are affected.

Prevalence

Fetal and neonatal alloimmune thrombocytopenia is estimated to occur in as many as 1 in 1,200 live births.

Diagnosis

When there is no history of thrombocytopenia, the condition is usually diagnosed after birth, when a low platelet count or bleeding is detected in the newborn.

In some cases, the condition may be suspected during pregnancy if a fetal ultrasound detects intracranial hemorrhage, which may indicate thrombocytopenia.

For women who have had a previous pregnancy affected by platelet alloimmunization, there is a high likelihood of future pregnancies being affected even more severely. Subsequent pregnancies should be closely monitored and managed.

If you and your baby are at risk of thrombocytopenia or the condition is suspected, you may be referred to a fetal center for specialized care.

Specialized Evaluation and Care

At Texas Children’s Fetal Center, we arrange for you to visit as quickly as possible for a comprehensive evaluation by a team of specialists experienced in diagnosing and treating this fetal blood disorder, including maternal-fetal medicine (MFM) physicians, fetal intervention specialists, fetal imaging experts, fetal cardiologists, neonatologists, and hematologists.

Blood tests will be performed on the mother and father.

An amniocentesis may be performed to assess for fetal infections, chromosomal abnormalities or other genetic syndromes.

Following testing, our specialists will meet with you about your results, answer any questions you have, and discuss treatment options. 

Treatment During Pregnancy

You and your baby will be closely monitored throughout pregnancy with regular ultrasounds to assess fetal health.

If the fetus is considered to be at high risk for platelet alloimmunization, treatment may be offered to decrease the risk of internal bleeding.

Treatment strategies during pregnancy include:

• Weekly administration of intravenous immunoglobulin (IVIg) to minimize the destruction of platelets
• Daily steroids
• Delivery by cesarean to minimize risks of intracranial hemorrhage

After delivery of the baby, additional treatment is often necessary, including medications or platelet transfusion.

Talk with your healthcare team about the risks involved in your recommended treatment plan, to help you make the most informed decision for you and your family.

Delivery

We recommend delivery at a hospital with the expertise and resources required to care for pregnancies involving thrombocytopenia, including the highest level neonatal intensive care unit (NICU), if needed. 

A cesarean delivery to minimize the risks of intracranial hemorrhage that might occur during a vaginal delivery and postnatal care should be carefully planned and coordinated with a team of maternal-fetal medicine specialists, neonatologists, and pediatric specialists experienced in working together to treat this fetal blood disorder, for the best possible care every step of the way.

Our Fetal Center team works closely with pediatric experts from Texas Children’s Hospital, consistently ranked one of the best children’s hospitals in the nation by U.S. News & World Report. For our patients, that means seamless access to the critical care services and specialists your baby may need immediately after birth, with no transfers required.

It also means the pediatric experts responsible for treating your child at delivery have been part of their care team prior to birth.

Postnatal Care Team

Treatment needs after birth may include:

• Ultrasound of the baby’s brain to check for intracranial bleeding
• Blood tests to evaluate and monitor the severity of the thrombocytopenia
• Platelet transfusion
• Intravenous immunoglobulin (IVIg) therapy

Depending on his or her condition, your baby’s postnatal care team may include:

• Neonatologist
• Hematologist
• Neurologist

Why Texas Children’s Fetal Center?

• A single location for expert maternal, fetal and pediatric care. At Texas Children’s Hospital, you and your baby receive the specialized care required for the diagnosis and treatment of fetal thrombocytopenia all in one location, for highly coordinated care and treatment planning, including immediate access to our level IV NICU.
• A skilled, experienced team with proven outcomes. We have a dedicated team of maternal-fetal medicine specialists, fetal imaging experts, hematologists, neonatologists, and others who work in concert to care for you and your baby every step of the way, using proven protocols we’ve developed over the years. With their combined expertise and unified approach, this team offers the best possible care for babies with this blood disorder.
• We care for your child’s needs at every stage of life. Our comprehensive approach starts with your first prenatal visit and continues through delivery, postnatal care, and beyond, thanks to one of the nation’s leading teams of fetal and pediatric specialists for the care and treatment of rare fetal conditions.

Additional Resources

• Six things to consider when choosing a fetal center