I started practicing primary care at Boston Medical Center in 2001 and was part of the Faculty of Boston University's School of Medicine. In 2010, I transitioned to the Quincy and Braintree area to continue serving as a primary care physician and urgent care provider. I graduated from the University of Puerto Rico School of Medicine and completed my residency in Internal Medicine at the Hospital of Saint Raphael/Yale-New Haven Hospital.

Having grown up on the South Shore, it is a pleasure to care for patients of this region. I served in the US Navy following medical school and completed my surgical training through the Navy. Following multiple military assignments, I chose to return to the area in order to serve my local community and reside closer to my family. 

My mission as an emergency department physician is to provide timely and excellent care to patients while helping them through what are likely very stressful and difficult emergency situations.

I grew up in southern New Hampshire and attended Providence College in Rhode Island. I then obtained my MD at the University of Connecticut. I completed my emergency medicine residency at the University of Cincinnati and while I loved the Midwest, I always planned to come back to New England and was happy to move to the South Shore. In my free time I enjoy hiking, skiing, and spending time with family and friends.

Dr. O'Brien is Medical Director of Maternal-Fetal Medicine at South Shore Health. 

As a Maternal-Fetal Medicine physician, I am dedicated to caring for women and families navigating high-risk and medically complex pregnancies with expertise, compassion, and individualized attention. 

I strive to integrate evidence-based medicine with a holistic approach that recognizes the physical, emotional, and social factors that shape each patient’s experience. 

I am also committed to advocating for equitable healthcare and improving access and outcomes for marginalized and underserved communities.