Dr. Mara Rosner: Returning to Her Roots in Fetal Medicine at CHOP

In November, Dr. Mara Rosner joined the Richard D. Wood Jr. Center for Fetal Diagnosis and Treatment (CFDT) at Children’s Hospital of Philadelphia (CHOP). Nearly two decades after completing her fetal therapy fellowship at CHOP, she returns as an accomplished maternal-fetal medicine (MFM) specialist whose work has helped advance diagnosis, fetal surgical interventions and education in the field.

In this conversation, Dr. Rosner reflects on what drew her to fetal medicine, what inspires her approach to patient care, and what excites her most about rejoining the CHOP team.  

What inspired you to pursue maternal-fetal medicine as your specialty?

I was drawn to women’s health and maternal and child health from a fairly young age. In medical school at Tulane, I got a master’s in public health and chose the maternal and child health track — it was the one that called to me. And when I became an obstetrician, which aligned perfectly with those interests, I found myself gravitating toward critical care and surgical subspecialties. It wasn’t until I truly explored those options that I discovered fetal therapy.  

What’s remarkable is that even though I’m technically caring for a fetus, the work feels deeply centered on maternal health. It’s about helping women with their pregnancies in ways I never knew were possible.

Your fellowship at CHOP in 2007 was formative. What do you remember most?

I had almost no experience with fetal therapy during my OB/GYN residency — that training is focused on childbirth and gynecology. At CHOP, I worked with fetal medicine pioneers N. Scott Adzick, MD, and Alan Flake, MD. It was inspirational to realize there was this entire other way of helping women.

And I discovered something surprising about myself: I found peace in the ultrasound room. I already loved ultrasound, which was unusual for a resident, but sitting down next to a pregnant patient in that dark room, probe in hand — there’s something meditative about it. It’s genuinely miraculous to see the fetus, and I think it’s miraculous for the patient, too.

How has your approach to patient care evolved?

My general approach has actually stayed the same, which is that I’m fundamentally drawn to the concept of personal autonomy and freedom. I approach caring for the fetus as part of maternal health. I’m always considering the fetus in the context of the mother’s health and her needs. What has changed is that I’m now a mother and a wife. I don’t think you need to be a parent to be empathetic, but it has certainly deepened my ability to relate to what patients are experiencing.

You’re returning to CHOP after building your career elsewhere. Why now?

CHOP is where I was inspired. The pediatric care here is unparalleled — there’s expertise in every possible pediatric condition, which matters because fetuses can have extremely rare conditions that are new to me, even now. The interdisciplinary piece is one of the most beautiful aspects of fetal therapy. You work with doctors in every subspecialty, and then you hand over the baby to pediatricians you trust after delivery.

There’s no group in the world more experienced or caring than the group at CHOP. What draws me back now is the opportunity to work in that environment where the depth of knowledge in pediatric disease is unmatched.

What makes you particularly suited to this moment at CHOP?

I have some specific interests that I think are unique. I’ve done extensive work in first-trimester diagnosis. I also have deep experience in neurosonography — advanced ultrasound of the fetal brain — and I trained with world experts in that area. I’m excited to explore that with the team. And I’ve had a lab at Johns Hopkins focused on monochorionic twins where we collected and analyzed data that led to new discoveries about patient counseling and management. I hope to continue that work.

But beyond specific expertise, I’m bringing a culture of doing everything you can for your patients and really being there for them. I think that culture already exists at CHOP, and I want to enrich it.

What emerging areas in fetal medicine do you find most promising?  

In utero medical therapy for fetal diseases like spinal muscular atrophy is a growing area and really exciting. As more disease-specific drugs are developed, we’re learning how to treat many of these conditions before birth.

We’re also working on developing more minimally invasive treatments — smaller instruments, smaller incisions, earlier interventions — to minimize trauma to the uterus. There’s huge opportunity there. And gene therapy is another really exciting frontier for treating the fetus.

What opportunities for research or collaboration at CHOP excite you most?

I hope to continue working with the spinal muscular atrophy team at CHOP. There’s also a collaboration I’m hoping to be involved in to understand the genetic basis for and treatment of vascular and lymphatic anomalies in the fetus — specifically somatic mutations that create vascular or lymphatic tumors. Understanding their genetic basis could help us learn how to treat them before birth.

How do you approach collaboration with referring physicians?

I was a referring physician before, so I understand how formative those collaborations can be. I love that CHOP isn’t just here to receive patients, but also to be a resource — to answer questions, educate and serve as a sounding board.

Not every call means a referral; sometimes a physician just wants to talk through a case, and that’s valuable. Building those relationships is one of the most fun parts of being a fetal therapy doctor.

How do you approach conversations with families facing difficult diagnoses?

I approach it first as an educator. I start by teaching them about the condition — helping them understand what’s going on. Once they do, it’s my turn to listen: to hear their values, their needs and their wants. Once I understand their values and they understand the issues at hand, we can work together to figure out what path is best for them.

And what impact do you hope to have?

For patients, I want them to feel like I tried my best to help them get what they needed. For colleagues, I hope they feel celebrated by me and that they can rely on me and trust me. In fetal medicine, I hope to continue my side project on curriculum development for MFM fellows around the country. We need to spread knowledge of fetal physiology and therapy wider, so people know when to call and who to call. I want to raise the bar.

Dr. Rosner’s arrival at CHOP marks both a homecoming and a new chapter — one grounded in experience, education and a deep commitment to supporting families with compassion and clarity.