Effective new treatments are still urgently needed for early-onset severe hemolytic disease of the fetus and newborn (HDFN), as many high-risk pregnancies continue to require invasive procedures and result in significant complications for both mother and baby, according to a study published recently in Pregnancy.
“This study demonstrated the substantial challenges associated with current practices for managing [early onset severe] HDFN in the setting of experienced healthcare centers,” the authors wrote.
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The CLARITY study followed 15 pregnant individuals at high risk for this early onset severe HDFN across seven countries between 2019 and 2023. Despite specialized care, only two pregnancies, or 13%, reached the goal of delivering at or after 32 weeks without needing intrauterine transfusions. Most participants, 87%, required at least one transfusion during pregnancy, with a median of four procedures and some needing as many as 11.
“The affected neonates continued to experience hemolytic anemiaAnemia A condition that occurs when the body doesn’t have enough healthy red blood cells to carry oxygen to its tissues. In HDFN, anemia occurs when maternal antibodies destroy fetal red blood cells. requiring neonatal transfusions, prolonged hospitalizations, and NICU hospitalizations,” said the authors.
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Still, outcomes showed some improvement compared with prior pregnancies. Fourteen of the 15 pregnancies, or 93%, resulted in live births. Half of these births were preterm, and 86% were delivered by cesarean section. One fetal death occurred at about 16 weeks. Many procedures began early, with the first transfusion typically performed around 24 weeks gestational age, and in some cases as early as 13 weeks.
For newborns, care needs remained high after delivery. All 14 infants required treatment for jaundiceJaundice A common symptom of HDFN, jaundice is caused by excess bilirubin and is characterized by a yellow tint to the skin or eyes. using phototherapyPhototherapy A treatment that uses special blue light to help newborns break down bilirubin and prevent kernicterus.. About 21% needed exchange transfusions, a more intensive procedure, while 64% required simpler blood transfusions within the first 12 weeks of life. Only three infants did not need transfusions. Nearly all infants, 93%, were admitted to the neonatal intensive care unit, with hospital stays ranging from a few days to more than two months.
Some patients received intravenous immunoglobulinIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus., or IVIGIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus., an experimental approach aimed at reducing damage to fetal red blood cells. Among the eight participants who received IVIG, two reached the study’s primary goal without needing transfusions, compared with none in the group that did not receive IVIG. However, IVIG also caused side effects in 38% of those treated, including headache, rapid heart rate and, in one case, aseptic meningitis.
For patients and families, these findings mean that even with expert care, this condition often involves repeated procedures during pregnancy, early delivery and intensive treatment for newborns. While survival rates have improved, the burden remains high. The study underscores the need for safer and more effective therapies that can prevent severe anemia earlier and reduce the need for invasive interventions.
