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MotherToBaby

Medications and More during pregnancy and breastfeeding

Hydroxyurea (Hydrea®; Siklos®)

Selected References:

  • Abduljalil K, at al. 2026. Physiologically based pharmacokinetic modelling of hydroxyurea in patients with sickle cell disease: a special focus on lactating women and breastfed infants to inform safe dosing and breastfeeding strategies. pharmaceuticals (Basel), 19(2):220.  
  • Al Sulaimani R, et al. 2025. Safety of hydroxyurea in pregnancy: a systematic review of the literature. J Obstet Gynaecol Can, 47(7):102924.  
  • American Health Packaging. Updated 2026. Hydroxyurea Product Label. National Institute of Health DailyMed database. Available at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c84a2241-6c05-480f-8a5b-049e08c27d73#. [Accessed May 2026.]  
  • Ballas SK, et al. 2009. Exposure to hydroxyurea and pregnancy outcomes in patients with sickle cell anemia. J Natl Med Assoc, 101(10):1046-1051. 
  • Bykal C, et al. 2000. Use of hydroxyurea and alpha-interferon in chronic myeloid leukemia during pregnancy: a case report. Eur J Gynaecol Oncol, 21:89-90. 
  • Bhattacharjee U, et al. 2024. Maternal and foetal outcomes of newly diagnosed chronic myeloid leukemia during pregnancy and its long-term impact. Indian J Hematol Blood Transfus, 40(4):687-693.  
  • Boafor TK, et al. 2016. Pregnancy outcomes in women with sickle-cell disease in low and high income countries: a systematic review and meta-analysis. BJOG, 123:691-698.  
  • Byrd DC, et al. 1999. Hydroxyurea in two pregnant women with sickle cell anemia. Pharmacotherapy, 19:1459-1462. 
  • Celiloglu M, et al. 2000. Hydroxyurea treatment for chronic myeloid leukemia during pregnancy. Acta Obstet Gynecol Scand, 79:803-804. 
  • Charache S, et al. 1995. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. N Engl J Med, 332:1317-1322. 
  • Cinkotai KI, et al. 1994. Pregnancy after treatment with hydroxyurea in a patient with primary thrombocythaemia and a history of recurrent abortion. J Clin Pathol, 47:769-770.  
  • Corsia A, et al. 2025. Maternal and perinatal outcomes of sickle cell disease in pregnancy: a nationwide study in France. Br J Haematol, 206(4):1218-1227.  
  • de Montalembert M, et al, All ESCORT HU Investigators. 2021. Real-Life experience with hydroxyurea in patients with sickle cell disease: results from the prospective ESCORT-HU cohort study. Am J Hematol, 96(10):1223-1231. 
  • DeBaun MR. 2014. Hydroxyurea therapy contributes to infertility in adult men with sickle cell disease: a review. Expert Review of Hematology, 7(6):767–773.  
  • Dell’Isola A, et al. 1997. Essential thrombocythemia in pregnancy. a case report and general considerations. Minerva Ginecol, 49:165-172.  
  • Delmer A, et al. 1992. Pregnancy during myelosuppressive treatment for chronic myelogenous leukaemia. Br J Haematol, 82:783-784. 
  • Desai G, et al. 2025. Lower rates of maternal morbidities among pregnant women suffering from sickle cell disease who are exposed to hydroxyurea, a retrospective study from tribal area of Western India. Expert Rev Hematol, 18(12):1099-1105. 
  • Diav-Citrin O, et al. 1999. Hydroxyurea use during pregnancy: a case report in sickle cell disease and review of the literature. Am J Hematol, 60:148-150. 
  • Doney KC, et al. 1979. Combination chemotherapy for acute myelocytic leukemia during pregnancy: three case reports. Cancer Treat Rep, 63:369-371. 
  • E.R. Squib & Sons, LLC. 2022. Hydrea Product Label. National Institute of Health DailyMed database. Available at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=050bd2a2-a125-721a-e366-255c5466f018. [Accessed 10 Jan 2024.] 
  • Fadilah SA, et al. 2002. Successful treatment of chronic myeloid leukemia during pregnancy with hydroxyurea. Leukemia, 16:1202-1203. 
  • Fernandez H. 1994. [Essential thrombocythemia and pregnancy]. J Gynecol Obstet Biol Reprod, 23(1):103-104. 
  • Fitzgerald JM, et al. 1993. The combination of hydroxyurea and leucapheresis in the treatment of chronic myeloid leukaemia in pregnancy. Clin Lab Haematol, 15:63-65. 
  • Grigg A. 2007. Effect of hydroxyurea on sperm count, motility and morphology in adult men with sickle cell or myeloproliferative disease. Intern Med J, 37(3):190-192. 
  • Habibi A, et al. 2023. Outcomes of pregnancy in sickle cell disease patients: results from the prospective ESCORT-HU cohort study. Biomed, 11(2):597. 
  • Idris IM, et al. 2025. A controlled trial for preventing priapism in sickle cell anemia: hydroxyurea plus placebo vs hydroxyurea plus tadalafil. Blood, 145(26):3101-3112.  
  • Italia KY, et al. 2010. Exposure to hydroxyurea during pregnancy in sickle-beta thalassemia: a report of 2 cases. J Clin Pharmacol, 50(2):231-234. 
  • Jackson N, et al. 1993. Hydroxyurea treatment for chronic myeloid leukaemia during pregnancy. Br J Haematol, 85:203-204. 
  • Koh LP, et al. 2002. Four pregnancies in two patients with essential thrombocythaemia – a case report. Ann Acad Med Singapore, 31:353-356. 
  • Kroner BL, et al. 2022. Pregnancy outcomes with hydroxyurea use in women with sickle cell disease. Am J Hematol, 97(5):603–612. 
  • Liebelt E, et al. 2007. NTP-CERHR expert panel report on the reproductive and developmental toxicity of hydroxyurea. Birth Defects Res B Dev Reprod Toxicol, 80(4):259-366.  
  • Malowski AK, et al. 2021. Distinct maternal and fetal pregnancy outcomes in women with sickle cell disease can be predicted using routine clinical and laboratory data. Brit J Haematol, 194(6):1063–1073. 
  • Marahatta A, Ware RE. 2017. Hydroxyurea: analytical techniques and quantitative analysis. Blood Cells Mol Dis, 67:135–142. 
  • Medunik. Updated 2026. Hydroxyurea Product Label. National Institute of Health Dailymed Database. Available at https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=76957c0d-0f98-4376-bb06-eee651adc09d. [Accessed May 2026]. 
  • National Heart, Lung, and Blood Institute. 2014. Evidence-based management of sickle cell disease: expert panel report, 2014. U.S. Department of Health and Human Services, National Institutes of Health.  
  • Oskuie AE, et al. 2011. Successful outcome of pregnancy in a case of essential thrombocytosis treated with hydroxyurea. Indian J Cancer, 48(2):268-269. 
  • Oteng-Ntim E, et al. 2015. Adverse maternal and perinatal outcomes in pregnant women with sickle cell disease: systematic review and meta-analysis. Blood, 125:3316–3325. 
  • Pata O, et al. 2004. Polycythemia vera and pregnancy: a case report with the use of hydroxyurea in the first trimester. Am J Perinatol, 21:135-137.
  • Patel M, et al. 1991. Use of hydroxyurea in chronic myeloid leukemia during pregnancy: a case report. Am J Obstet Gynecol, 165:565-566. 
  • Pecker LH, Kuo KHM. 2022. Go the distance: reproductive healthcare for people with sickle cell disease. Hematol Oncol Clin North Am, 36(6):1255–1270. 
  • Poli P, et al. 2020. Exposure to hydroxyurea during pregnancy: a case report of congenital malformation, update on the current evidence and management of sickle cell disease during pregnancy. Gynecol Obstet Case Rep, 6(5):28. 
  • Rustin GJS, et al. 1984. Pregnancy after cytotoxic chemotherapy for gestational trophoblastic tumours. Br Med J, 288:103-106.  
  • Rogers DT, Molokie R. 2010. Sickle cell disease in pregnancy. Obstetrics and gynecology clinics of North America, 7(2):223–237. 
  • Saleh AJM, et al. 2014. Leukemia during pregnancy: long term follow up of 32 cases from a single institution. Hematol Oncol Stem Cell Ther, 7(2):63-68. 
  • Silva FAC, Ferreira ALCG, Pimentel LM, et al. 2021. The use of hydroxyurea during pregnancy in sickle cell anemia women: a case series and literature review. J Hematol Res, 8:6-10. 
  • Sulaimani, A. et al. 2025. Safety of hydroxyurea in pregnancy: a systematic review of the literature. Journal of Obstetrics and Gynaecology, JOGC, 47(7):102924. 
  • Szanto F, Kovacs L. 1993. [Successful delivery following continuous cytostatic therapy of a leukemic pregnant women]. Orv Hetil, 34(10):527-529. 
  • Tertian G, et al. 1992. Hydroxyurea and pregnancy. Am J Obstet Gynecol, 166:1868. 
  • Thauvin-Robinet C, et al. 2001. Exposure to hydroxyurea during pregnancy: a case series. Leukemia, 15:1309-1311. 
  • Ware RE, et al. 2020. Hydroxyurea exposure in lactation: a pharmacokinetics study (HELPS). J Pediatr, 222:236–239. 
  • Warncke K, et al. 2025. Hyperhemolysis in a sickle cell disease patient in pregnancy. Ann Hematol, 104(8):4245-4249. 
  • Wright CA, Tefferi A. 2001. A single institutional experience with 43 pregnancies in essential thrombocythemia. Eur J Haematol, 66:152-159. 

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