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Arianna Cassidy


Co-director, Multidisciplinary Approach to the Placenta Service
Cookie baker and recreational runner

About me

Pronouns: She | Her | Hers

Dr. Arianna Cassidy is a perinatologist, an obstetrician who specializes in high-risk pregnancies. She cares for patients with pre-existing medical issues that can affect pregnancy as well as conditions that can develop during pregnancy. She also cares for patients who require complex surgery during pregnancy or need C-section births. She has a special interest in placental conditions, particularly placenta accreta spectrum (PAS) disorder (in which the placenta grows into the uterine wall).

Cassidy's research focuses on understanding PAS and improving the care of pregnant patients who develop it, including looking at how providers from relevant specialties can work in concert to prevent, detect and address abnormal development of the placenta. She also studies COVID-19 infection and vaccination in pregnancy, the intersection between maternal-fetal medicine and family planning, and quality improvement measures.

Cassidy earned her medical degree at UCSF, where she also completed a residency in obstetrics and gynecology and a fellowship in maternal-fetal medicine.

  • Education

    UCSF, MD, 2016

  • Residencies

    UCSF, Obstetrics and Gynecology, 2020

  • Fellowships

    UCSF, Maternal Fetal Medicine, 2023

  • Board Certifications

    Obstetrics and Gynecology, American Board of Obstetrics and Gynecology

  • Academic Title

    Assistant Professor

Where I see patients (2)