Fetal complications in twin pregnancies are challenging to diagnose, can threaten the survival of one or both twins, and often result in secondary complications that put pregnancies at risk for early delivery. Successful diagnosis and treatment require an experienced team with cutting-edge diagnostic techniques, advanced surgical skill and a comprehensive approach to care.
The multidisciplinary team at the Center for Fetal Diagnosis and Treatment at The Children’s Hospital of Philadelphia has more than 15 years experience managing twin pregnancies complicated by birth defects, among the greatest collective experience in the world. The team evaluates nearly 200 sets of twins a year using state-of-the-art imaging technology, including high-resolution ultrasound and detailed fetal echocardiography. On occasion, fetal MRI, a technique pioneered at CHOP in the 1990s, is also used.
“There are so many subtle factors at play during the evaluation of these complex twin pregnancies,” Mark Johnson, MD, Director of Obstetric Services at the Center, says. “How they present can be amazingly variable. Each case is as unique as a fingerprint.”
Complications in identical twin pregnancies can include twin-twin transfusion syndrome (TTTS ), selective (only one twin involved) severe placental insufficiency and growth restriction, prenatal death of one twin, one twin with a major birth defect or genetic abnormality, twin reversed arterial perfusion (TRAP) sequence, both twins within one amniotic sac (monoamniotic) with entanglement of their umbilical cords, and conjoined twins.
Continuum of care
Specialists at the Center partner with referring maternal-fetal medicine specialists and/or primary obstetricians to provide a seamless continuum of care, discussing the diagnosis and treatment options, offering suggestions for follow-up if fetal surgery is required, and remaining available for consultation for the remainder of the pregnancy as part of the patient’s ongoing perinatal management team.
“We really value and encourage the collaborative team approach and the opportunity to work with referring doctors, with the goal of patients returning to their home institution for management and delivery,” Johnson says.
CHOP’s unique cardiovascular scoring system, created in collaboration with the Fetal Heart Program, measures the existence and progression of adaptive cardiovascular changes, a common complication in twin anomalies, resulting in more informed treatment decisions for TTTS. When laser therapy is indicated, the team studies patients’ cardiac function scores before treatment, 24 hours after the procedure and when they return one week later for follow-up to look at changes in response to the intervention.
If indicated, mothers can deliver in CHOP’s Garbose Family Special Delivery Unit, the first birth facility in the world designed for mothers carrying babies with known birth defects, where the most advanced neonatal and cardiac intensive care units and operative facilities are within steps of their delivery rooms. Children’s Hospital’s Neonatology services, consistently ranked among the best in the nation by U.S. News & World Report, and other top-ranked subspecialties within the Hospital help provide each family with multidisciplinary counseling and care before and after birth.
“These experienced subspecialists can provide the family with a better understanding of what’s going on, what the risks are to the pregnancy and what the possible outcomes could be after the babies are born, depending on what complications of the identical twinning they may face,” Johnson says.
With the help of families and their delivery teams, researchers at the Center analyze placentas and birth and outcome data from monochorionic twins that have undergone fetal intervention for TTTS in an effort to understand the impact of fetal therapy, refine prenatal counseling and develop recommendations for management of these complex conditions.
“Together, as a team, referring physicians and the staff at our Center have made great advances not only in understanding complications of identical twins, differentiating one problem from another, and refining treatment strategies and follow-up, but also in offering patient-specific management options to improve outcomes,” Johnson says.