Plasma donation collects the liquid portion of the blood, which contains proteins, antibodies, and clotting factors, used to create therapies for people with immune deficiencies, bleeding disorders, and other serious illnesses. Following childbirth, a deferral period is a standard safety protocol implemented by donation centers. The temporary inability to donate plasma is based on two concerns: ensuring the mother’s physical recovery and mitigating a specific immunological risk to the transfusion recipient.
Physiological Recovery Postpartum
The deferral period prioritizes the mother’s health as she recovers from pregnancy and delivery. Childbirth results in significant blood loss, depleting the body’s reserves of iron and essential nutrients. Donating plasma soon after delivery can aggravate this issue, often leading to or worsening postpartum anemia.
Pregnancy increases circulating blood volume significantly. The body requires time to rebalance its fluid and protein levels. Donating plasma too early can disrupt this process, potentially causing low plasma protein levels and delaying recovery. The demands of caring for a newborn combined with a donation can exacerbate fatigue. Centers require time for the body to naturally replenish these resources.
The Specific Immunological Risk of TRALI
The most significant reason for plasma deferral in anyone who has been pregnant is the risk of Transfusion-Related Acute Lung Injury (TRALI). TRALI is a rare but serious complication for transfusion recipients, where the patient experiences acute respiratory distress, typically within six hours of receiving a blood product. This condition is a leading cause of transfusion-related mortality.
The risk stems from antibodies a mother may develop during pregnancy when her immune system is exposed to the fetus’s blood. The fetus inherits half of its human leukocyte antigens (HLA) and human neutrophil antigens (HNA) from the father, which are foreign to the mother’s immune system. In response, the mother’s body can create specific anti-HLA and anti-HNA antibodies that remain in her plasma long after the pregnancy ends.
If plasma containing these antibodies is transfused, they can react with the recipient’s white blood cells, causing damage to the small blood vessels in the lungs. This reaction leads to non-cardiogenic pulmonary edema. Studies indicate that between 10% and 20% of women who have been pregnant develop these antibodies. Because the antibodies are permanent, many donation centers permanently defer women who test positive for them from donating plasma or platelets.
Standard Deferral Durations and Breastfeeding Status
The initial deferral period post-delivery is typically a minimum of six weeks, regardless of the type of delivery. This six-week period is the minimum time recommended for the uterus to return to its normal size and for the body to begin restoring its blood volume. However, many donation centers extend this waiting period to six months or even up to one year to ensure a more complete physiological recovery.
Breastfeeding status often extends the deferral timeline because the mother’s body prioritizes fluid and nutrient transfer to the infant. Plasma donation involves removing a large volume of the liquid portion of the blood, which can significantly impact the mother’s hydration levels. A temporary reduction in the mother’s milk supply is a potential consequence of plasma donation, which could compromise the baby’s nutrition.
For this reason, some organizations advise against donation while breastfeeding, or recommend waiting until the infant is receiving supplemental nutrition. After the minimum deferral period, a new mother must meet all standard eligibility criteria, which includes passing a physical screening and a blood test to confirm adequate hemoglobin and iron levels.
Comparing Donation Rules for Different Blood Products
The rules for donation vary significantly depending on the specific blood product the center is collecting. Whole blood donation collects all blood components together and focuses primarily on the donor’s iron and red blood cell count. The deferral period is usually the minimum six weeks to allow for recovery from postpartum iron depletion. Women who are deferred from plasma or platelet donation due to antibodies are still welcome to donate whole blood or double red blood cells.
In contrast, plasma and apheresis platelet donations are governed by stricter rules related to TRALI risk. These products contain a high concentration of plasma, which is where the potentially harmful antibodies reside. The process for platelet donation is similar to plasma donation, and the same antibody-testing rule applies to women who have been pregnant. If a woman has tested positive for HLA or HNA antibodies, she is typically deferred from donating both plasma and platelets, while her red cell donations remain safe for transfusion.