Portrait of Arianna Cassidy
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Arianna Cassidy, MD

She | Her | HersObstetrics • Maternal and Fetal MedicineCo-director, Multidisciplinary Approach to the Placenta Service
Complex Obstetric Medicine Mission Bay
415-353-3400
Portrait of Arianna Cassidy
Portrait of Arianna Cassidy
ucsf logo

Arianna Cassidy, MD

She | Her | HersObstetrics • Maternal and Fetal MedicineCo-director, Multidisciplinary Approach to the Placenta Service
Complex Obstetric Medicine Mission Bay
415-353-3400

On this page

About me

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 & training

Board certification

  • Obstetrics & Gynecology, American Board of Obstetrics and Gynecology

Fellowship

  • Maternal and Fetal Medicine, UCSF Graduate Medical Education

Residency

  • Obstetrics & Gynecology, UCSF Graduate Medical Education

Degree

  • MD, UCSF School of Medicine

My expertise

Locations

    Reviews

    Average rating

    4.9
    4.9 out of 5 Stars
    32 ratings
    About provider reviews

    Showing 1-6 of 6 reviews

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    • 4.3 out of 5 Stars
      December 17, 2025

      They serve us well

    • 5 out of 5 Stars
      February 6, 2025

      Dr. Cassidy is amazing. She guided me through my pregnancy with care and great advice. So happy she was by OB.

    • 5 out of 5 Stars
      January 26, 2025

      Explained things slowly, clearly, and thoroughly. Very polite and friendly as well!

    • 5 out of 5 Stars
      September 19, 2024

      Dr Cassidy blew me away with her kindness, empathy, and expertise

    • 5 out of 5 Stars
      September 8, 2024

      Great staff!! Very welcoming and informative!

    • 5 out of 5 Stars
      April 23, 2024

      Extremely positive experience. She was incredibly thorough, deliberate, and kind. She gave me tons of info that really helped me understand the possible issues, and lower my anxiety. I felt like she was very present and compassionate when I was emotional, and extremely thorough and competent when I wanted information. She spent a LONG time with me, and I was so grateful for it.

    Please check with your health insurance plan regarding coverage for this type of care. Not all providers at UCSF Health are covered by every insurance plan.

    For informational purposes only, a link to the federal Centers for Medicare and Medicaid Services (CMS) Open Payments web page is provided here. The federal Physician Payments Sunshine Act requires that detailed information about payment and other payments of value worth over ten dollars ($10) from manufacturers of drugs, medical devices, and biologics to physicians and teaching hospitals be made available to the public.