I am board certified in Internal Medicine and Geriatric Medicine, with clinical epidemiology training. My clinical expertise include assisting geriatric patients with informed-decision making based on risk factors and predictors of long-term functional outcomes, and implementing interventions to optimize functional and cognitive outcomes.   

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. 

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.

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.

As an admitting hospitalist, my focus is to facilitate a smooth transition between the emergency department and the inpatient  admission. 

Waiting to be admitted to the hospital can be nerve wracking, emotional, and even scary. My goal is to ease  your transition from waiting in the ER to being admitted, explain your condition, and answer all questions you may have. Raised and educated locally, it is my pleasure to serve this wonderful community of people who call the South Shore home. In my free time, I enjoy traveling, spending time with family and friends, and exploring/discovering all that the area has to offer.   

Patients with vascular disease often face many challenges—medical and otherwise. Consequently, I recognize that there are many important aspects to your care.  I also appreciate that having surgery is a major life event. With all of this in mind, I will do my best to provide you with patient-centered, high quality, effective and compassionate care.