A blood transfusion involves administering blood or specific blood components from a donor into a patient’s circulatory system through an intravenous line. While this procedure is not routine during pregnancy, it becomes a life-saving measure when a woman experiences severe blood loss or dangerously low blood counts. The decision to transfuse is made to restore the blood’s capacity to carry oxygen and maintain overall circulatory function, often in urgent or emergency situations.
Why Transfusions Are Necessary During Pregnancy or Delivery
The need for a maternal blood transfusion during pregnancy or the immediate postpartum period typically stems from severe anemia or acute hemorrhage. Anemia, where the body lacks enough healthy red blood cells to carry adequate oxygen, may require transfusion if other treatments fail. Individuals with chronic conditions like sickle cell disease or thalassemia are at an increased risk of severe anemia during pregnancy and often require transfusions.
The most common and urgent indication is significant blood loss, medically termed hemorrhage. This can occur before delivery as an antepartum hemorrhage (e.g., placenta previa or placental abruption). However, the most frequent scenario is postpartum hemorrhage (PPH), which is excessive bleeding following childbirth.
In emergency situations, a rapid transfusion replaces lost blood volume, preventing hemorrhagic shock, organ damage, and death. Even if bleeding has stopped, a woman may still require a transfusion if she is severely anemic and experiencing symptoms like dizziness, weakness, or shortness of breath.
Understanding the Transfusion Process and Safety
Before a transfusion, rigorous blood typing and cross-matching are performed. This strict matching confirms the donor blood is compatible with the recipient’s blood type, minimizing the risk of a dangerous immune reaction. In non-emergency cases, the patient typically receives packed Red Blood Cells (RBCs), the component responsible for carrying oxygen.
The transfusion is administered through an intravenous (IV) line, usually inserted into a vein in the arm or hand. The blood product flows slowly via a drip, though this can be expedited in an emergency. Throughout the procedure, the patient is closely monitored by healthcare staff, who check temperature, heart rate, and blood pressure for signs of a reaction.
In instances of massive hemorrhage, the patient may also receive other blood components, such as platelets and plasma, in addition to red blood cells. Platelets help the blood clot, and plasma contains clotting factors, both of which are depleted during severe blood loss. O RhD negative red cells are reserved for life-saving situations when the patient’s blood type is unknown, as this is the universal donor type.
Risks and Complications Unique to Maternal Transfusions
While generally safe, blood transfusions carry specific risks, particularly for women of childbearing potential. One unique concern is alloimmunization, where the recipient develops antibodies against donor red blood cell antigens. This is a significant issue because these antibodies can cross the placenta in a future pregnancy and attack the fetus’s red blood cells, potentially causing Hemolytic Disease of the Fetus and Newborn (HDFN).
Standard transfusion risks include non-life-threatening reactions like fever, rash, or itchiness. More serious, though rare, complications involve the lungs and circulatory system. Transfusion-Associated Circulatory Overload (TACO) is a risk where the volume of transfused blood overwhelms the circulatory system, leading to acute pulmonary edema, especially in patients with pre-existing heart conditions.
Transfusion-Related Acute Lung Injury (TRALI) is a severe complication and the leading cause of transfusion-related fatality. TRALI involves the sudden onset of non-cardiac pulmonary edema within six hours of the transfusion. Women who have been pregnant are known to develop antibodies that can trigger TRALI if their blood is donated, leading to guidelines that minimize the use of plasma products from women with a history of pregnancy.
Intrauterine Transfusions: Transfusing the Fetus
Intrauterine transfusion (IUT) is a specialized procedure where blood is given directly to the fetus, not the mother. This intervention treats severe fetal anemia while the baby is still in the uterus, often preventing heart failure or hydrops. The most common indication for IUT is severe fetal anemia caused by red cell alloimmunization, such as Rh disease, where the mother’s antibodies destroy the fetus’s red blood cells.
Other conditions warranting IUT include severe anemia from parvovirus B19 infection or a large fetomaternal hemorrhage. The procedure is typically performed by a perinatologist, guided by ultrasound, by inserting a needle through the mother’s abdomen into the umbilical cord vein (intravascular transfusion). The fetus is often given medication to temporarily stop movement to ensure precise needle placement during the transfusion.
IUT may need to be repeated every few weeks until the fetus is mature enough for delivery, usually around 37 to 38 weeks of gestation. While the procedure is considered safe and successful for treating severe fetal anemia, potential risks include preterm labor, infection, or fetal distress.