ASH: No Specific Harms Found for Hydroxyurea Use During Pregnancy

TUESDAY, Dec. 9, 2025 (HealthDay News) — There is no clear evidence of harm for women receiving hydroxyurea (HU) during pregnancy for sickle cell disease, according to a study presented at the annual meeting of the American Society of Hematology, held from Dec. 6 to 9 in Orlando, Florida.

Anoosha Habibi, M.D., from the Hôpitaux Universitaires Henri Mondor in Creteil, France, and colleagues examined pregnancy outcomes following maternal and fetal HU exposure using data from prospective, multicenter, noninterventional cohort studies — the European Sickle Cell Disease COhoRT-HydroxyUrea (ESCORT-HU) and ESCORT-HU Extension.

A total of 3,145 patients were enrolled in 77 centers. During the studies, there were 246 pregnancies in 202 women: 125 in the ESCORT-HU and 121 in ESCORT-HU Extension trials. The researchers found that in 30 cases, HU treatment was interrupted before pregnancy and not resumed during pregnancy; of 213 pregnancies under HU, 18 and 23 were ongoing and resulted in voluntary abortions, respectively. Of the remaining 172 pregnancies, 131, 35, and 28 (76, 27, and 16 percent), respectively, resulted in live births, premature births, and miscarriages; two discontinued for medical reasons and there were two fetal deaths. Nine participants had an unknown outcome. There were no reports of maternal deaths. Outcomes included 19 normal births (65 percent), one premature birth, nine miscarriages, and one ongoing pregnancy among patients who stopped their HU before pregnancy. There were no malformations reported in the newborns related to HU. Forty-one percent of pregnancies reported transfusion support.

“Based on these findings, we call for a pragmatic approach. We have to decide case by case and evaluate the risk from transfusion and stopping hydroxyurea,” Habibi said in a statement.

Several authors disclosed ties to the biopharmaceutical industry.

Abstract

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