Hematopoietic stem cell donation, often referred to as bone marrow donation, is a life-saving procedure that provides healthy blood-forming cells to patients with blood cancers or other serious blood disorders. This process replaces a patient’s diseased or damaged marrow with a donor’s healthy cells, offering a chance at a cure. A common question for registered female donors is whether they can proceed with donation while pregnant. The definitive answer is no; pregnancy serves as a temporary medical deferral for the safety of both the mother and the developing fetus.
Medical Ineligibility During Pregnancy
The primary reason for temporary disqualification is the potential for increased medical risk to both the pregnant donor and her unborn child. Donating stem cells, whether through a surgical harvest or a non-surgical collection, introduces physiological stressors and medical interventions that are avoided during gestation. Even routine medical procedures carry an elevated risk profile for pregnant women due to significant changes in their cardiac, respiratory, and circulatory systems.
Donors undergoing a surgical bone marrow harvest require either general or regional anesthesia. Anesthesia during pregnancy is associated with a greater risk of complications, including impaired uteroplacental perfusion, which can lead to fetal distress. The procedure itself can involve a small amount of blood loss, which is usually well-tolerated but could exacerbate the physiological anemia common in pregnancy. The overarching concern is that any physical stress, medication exposure, or complication could potentially trigger a poor pregnancy outcome, such as premature delivery or miscarriage.
The ethical principle of “First, do no harm” is paramount in unrelated donation, especially since the fetus cannot consent to the risks. While elective surgery is generally avoided throughout pregnancy, the first trimester is particularly sensitive due to active organogenesis. This means the fetus is most vulnerable to external factors like medications or physiological stress, making pregnancy a mandatory temporary exclusion.
How Donation Method Impacts Safety
The two methods of stem cell collection—Peripheral Blood Stem Cell (PBSC) donation and surgical Bone Marrow Harvest—present distinct safety concerns during pregnancy. Surgical bone marrow harvest involves aspirating liquid marrow from the pelvic bone under anesthesia. This poses risks associated with surgery, including the potential for low blood pressure or oxygen levels in the mother, which directly impacts the fetus.
PBSC donation, the most common method, presents a unique pharmacological risk due to the drug used to mobilize the stem cells. To prepare for this non-surgical collection, the donor must receive daily injections of granulocyte colony-stimulating factor (G-CSF) for several days. The synthetic version stimulates the bone marrow to release a large number of stem cells into the circulating bloodstream.
The safety profile of G-CSF administration during pregnancy is not fully established in the context of healthy donors. Data on healthy donors is limited, and the drug is known to cross the placenta. Because G-CSF can stimulate fetal granulopoiesis and its long-term effects on the developing child are unknown, it is strictly avoided in healthy pregnant donors.
Resuming Donor Status Postpartum
A temporary deferral during pregnancy does not remove a registered woman from the donor registry; it simply makes her unavailable until she has fully recovered. Once the pregnancy is over, the donor must notify the registry, such as Be The Match, to begin the process of returning to active status. The typical waiting period before a woman can be considered for donation again is generally six to twelve months postpartum.
This waiting period ensures that the donor’s body has fully recovered from the physiological demands of pregnancy and childbirth, and it often coincides with the cessation of breastfeeding. The registry’s medical team will conduct a thorough re-evaluation to confirm the donor has returned to her baseline state of health, including addressing any anemia or other lingering postpartum conditions. A woman who was deferred due to pregnancy can usually resume her life-saving role as a potential donor after medical clearance.