Jenna Callaway, MD

Jenna Callaway, MD, is a pediatrician at Phoenix Children’s Pediatrics who treats children from birth through adolescence. She has special interests in caring for newborns, guiding new moms with breastfeeding, optimizing childhood nutrition and preventing obesity.

Dr. Callaway has a master’s degree in biology from Northern Arizona University in Flagstaff. She earned her medical degree from the University of Arizona College of Medicine – Phoenix. She then completed her pediatric residency training at Phoenix Children’s. 

Dr. Callaway believes in taking time to get to know and connect with her patients and their families. Her goal is to provide evidence-based, individualized care plans that will set patients up for a lifetime of health and success.

When not caring for her patients, Dr. Callaway spends time with her husband, daughter and their two dogs. She also enjoys reading, musical theater and going to the farmers market.

Mark Gettleman, MD

Mark Gettleman, MD, provides primary care at Phoenix Children’s Pediatrics for children of all ages from newborn through adolescence. 

Ever since he was a young boy, he knew he wanted to help people. Dr. Gettleman loves every aspect of being a pediatrician. Based on his skills, interests and personality, he can’t imagine doing anything else. 

After earning his medical degree at Loyola University Stritch School of Medicine, Dr. Gettleman completed his residency at Phoenix Children’s.

Dr. Gettleman believes laughter and play help children feel comfortable about going to the doctor. As a published author on raising happy, healthy kids, Dr. Gettleman feels it’s his job to help share parenting tips and give parents a clear understanding of treatment options for their child.  

When he’s not working, Dr. Gettleman enjoys spending time with his wife and two dogs. He also enjoys cooking and reading non-fiction. 

Mariah Scott, DO

Pediatrician Mariah Scott, DO, grew up in Chandler, Arizona. She had wanted to be a doctor since kindergarten, when she watched a video about the heart and human body. She developed her love for working with kids through babysitting and child care jobs as a teenager.

Dr. Scott attended the University of Arizona for her undergraduate degree, then went to Des Moines University in Iowa for medical school. She completed her pediatric residency at the Medical University of South Carolina in Charleston. She is dual board certified by the American Board of Pediatrics and the American Board of Obesity Medicine and has been in private practice since 2015.

Dr. Scott treats all aspects of child health but has special interests in asthma, attention-deficit hyperactivity disorder (ADHD) and obesity.

Her care philosophy is a team approach between the family and the medical team. She says the best part of her job is building relationships with patients. “It is such a privilege to watch a kid grow up, develop their own identity and personality, and know that you were part of helping them become who they are,” she says.

Stefanie Laystrom, PA-C

Physician assistant Stefanie Laystrom, PA-C, grew up in the Chicago suburbs, but she loves the mountains and sunshine of Arizona. A love for children fuels her passion for her work.

Stefanie received her bachelor’s degree in sports medicine from Central Michigan University and worked as a certified athletic trainer at Central High in Phoenix for several years. She graduated with a Master of Medical Science in Physician Assistant Studies from Midwestern University in Downers Grove, Illinois.

When she had an opportunity to return to Arizona and work at Phoenix Children’s Mesa Pediatrics, she jumped at the chance. She values Phoenix Children’s national and local reputation and the resources it offers.

"Kids are the best! They're smart and hilarious," Stefanie says. "It's so gratifying to help them feel better."

At home, Stefanie acts as chaos coordinator of three children, two silly dogs and a cat. When she has time to herself, Stefanie loves running mountain trails.

Sandra Sexton, CPNP-PC

As a certified pediatric nurse practitioner, Sandra Sexton has worked in pediatrics her entire career, beginning as a registered nurse for 20 years. She understands that caring for children also includes caring for the family, and she loves teaching her patients and families. 

In a hospital residency program, Sandra had on-the-job exposure to pediatrics working as a nurse. Fluent in Spanish, she interpreted for the residents and doctors, learning about pediatric health and wellness along the way. Becoming a certified pediatric nurse practitioner (CPNP) was the next step for her journey. 

Sandra earned her Master of Science in Nursing from Arizona State University in 2009. 

When she's not caring for patients, Sandra loves spending time with her husband of more than 30 years and her young granddaughter. She also enjoys exercising, practicing yoga, hunting and fishing.