Challenges and pitfalls in prenatal screening in pregnancies involving allogeneic stem cell transplantation...

Increasing numbers of successful pregnancies are reported in recipients of allogeneic hemopoietic stem cell transplantation (HSCT). These may occur naturally, or more commonly, through assisted reproduction. The pregnancy outcomes are usually normal. There are currently no guidelines on the prenatal management of pregnancies involving HSCT recipients. HSCT recipients are unique in that their red cells, lymphocytes and even the DNA in the circulation are donor derived. As a result, typical prenatal screening tests in parents, including mean cell volume (MCV), hemoglobin pattern, blood group, infective serology and DNA screening, are all affected. The MCV cannot be used as guide for iron and folate supplements, or for thalassemia and sickle cell anemia screening. Such screening must be based on pre-HSCT indices and pre-HSCT DNA samples. The risks for hemolytic disease of newborn and hepatitis B virus transmission have to be re-evaluated, based on both pre- and post-HSCT patient as well as donor blood group and serology results. Good communication between obstetricians and the HSCT physician is paramount to promote successful pregnancies in this distinct patient population.