Hydroxyurea Exposure Limiting Pregnancy and Follow-Up Lactation

The purpose of this research study is to document and understand the effects of hydroxyurea exposure for women with SCD and their babies, during both gestation and lactation.

Inclusion Criteria: * Medical records or data available from previous clinical care prior to June 20, 2019 of pregnant females with SCD, including women who miscarried, had a still birth, or completed labor at any gestational stage, with any hydroxyurea exposure during either pregnancy and/or while breastfeeding. * Medical records or data available from previous clinical care prior to June 20, 2019 about pregnancy and breastfeeding outcomes, both for babies with hydroxyurea exposure and other babies by these same women. Exclusion Criteria: * Unavailable medical records or lack of information about hydroxyurea exposure.