Our Sudbury Staff
The medical and administrative staff looks forward to getting to know you and your children. As a team, we hope to give you the best medical experience for your child as well as yourself. Please feel free express any questions or concerns and our medical staff/office staff will assist you as soon as possible.

Karen Ashworth, FNP, AE-C
Karen is a family nurse practitioner who joined Weston Pediatrics in March, 2011. She is our practices concussion specialist and asthma educator. She received her Masters of Science degree as a Family Nurse Practitioner from Regis College in 2002. She also has a Bachelors of Arts degree in Psychology. She has experience in urgent care, family medicine, and has worked in pediatric medicine for over 10 years. Her areas of interest include working with at-risk teens and young adults, adolescent-GYN, asthma education, concussion treatment and education, and integrative medicine.

Katherine M. Bui, MD
Dr. Katherine Bui received her undergraduate degree from Scripps College, in Claremont, California, and her M.D. from Boston University School of Medicine. Dr. Bui completed her residency at Massachusetts General Hospital where she pursued particular interests in infant development and medical education. She is board certified in pediatrics and is a member of the Massachusetts Medical Society and the American Academy of Pediatrics. Dr. Bui is in the office on Monday, Tuesday and Wednesday from 8am–5pm, and Friday from 8am–12pm.

Rosemarie Dieffenbach, MD, MPH
Dr. Rose Dieffenbach is board certified in general pediatrics and is a fellow of the American Academy of Pediatrics. Dr. Dieffenbach completed her undergraduate degree at UCLA, went on to obtain a Masters in Public Health from the University of Michigan and received her MD from George Washington University in Washington, D.C. She completed her pediatric residency training at University of California, San Francisco, then served in the U.S. Navy as a primary care pediatrician, stationed in Okinawa, Japan, Naples, Italy, and Bremerton, Washington. Before joining Weston Pediatrics, she cared for a variety of patients presenting to the Emergency Department at Children’s Hospital Boston. Dr. Dieffenbach enjoys caring for patients of all ages. Dr. Dieffenbach is in the office on Monday and Friday from 8am–12pm; and Wednesday and Thursday from 8am–5pm.

Robert H. Andler, MD, FAAP
Dr. Robert Andler received his undergraduate degree from Cornell University and his medical degree from the University of Virginia School of Medicine. He completed his pediatric internship and residency at Hasbro Children’s Hospital and Brown University in Providence, Rhode Island. Dr. Andler practiced in Rhode Island before joining Weston Pediatrics. He is board certified in pediatrics and is a fellow of the American Academy of Pediatrics. Dr. Andler is in the office on Monday from 8am–8pm; Wednesday and Friday from 8am–5pm; and Thursday from 8am–12 pm.

Shelly C. Bernstein, MD
Dr. Bernstein received his A.B. and Ph.D. in genetics from The University of Chicago and his M.D. from Pritzker School of Medicine of The University of Chicago prior to completing his pediatric residency at The Children’s Hospital in Boston. He then completed a hematology-oncology fellowship at Children’s Hospital and the Dana Farber Cancer Institute in Boston. He had a significant research career prior to joining Weston Pediatrics in 1990. Dr. Bernstein is an Assistant Clinical Professor of Pediatrics at Harvard Medical School and has ongoing teaching responsibilities of medical students and residents. He is board certified in pediatrics, a member of the Massachusetts Medical Society as well as a fellow of the American Academy of Pediatrics. Dr. Bernstein has a special interest in hematology and oncology and in addition to his patients at Weston Pediatrics, he also cares for children at The Jimmy Fund at the Dana Farber Cancer Institute. Dr. Bernstein is in the office on Monday, Tuesday, Thursday from 8am–5pm; and Wednesday from 1pm–8pm.