Physician Toolkit: Managing Complicated Twin Pregnancies

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 multidisciplinary team that employs cutting-edge diagnostic techniques, advanced surgical skill and a comprehensive approach to care.

Complicated twin pregnancies: referrals & interventions

The multidisciplinary team at the Center for Fetal Diagnosis and Treatment at The Children’s Hospital of Philadelphia has more than 20 years of experience managing twin and triplet pregnancies — among the greatest collective experience in the world. The team evaluates more than 200 multiple gestation pregnancies 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 — may be used.

Complications in twin pregnancies can include twin-twin transfusion syndrome (TTTS), selective (only one twin involved) severe placental insufficiency and growth restriction, in utero demise of one twin, one twin with a 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.

Specialists at the Center will partner with you 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 prenatal management team.

A quick look at our patient volumes prove the Center is a nationally recognized resource for evaluation and treatment of complicated twin pregnancies — specifically those affected by twin-twin transfusion syndrome.

Complicated Twin Pregnancies: Referrals

Total Referrals: 4,514

TTTS (2,435 cases)
Other (1,732 cases)
TRAP (220 cases)
Conjoined (127 cases)



Based on data from the Center for Fetal Diagnosis and Treatment at Children's Hospital of Philadelphia - 1995 through January 2024.


Complicated Twin Pregnancies: Interventions

Total Interventions: 1,349

Selective Laser Photocoagulation (764 cases)
Radiofrequency Ablation (455 cases)
Cord Transsection (119 cases)
Fetoscopic Other (11 cases)



Based on data from the Center for Fetal Diagnosis and Treatment at Children's Hospital of Philadelphia - 1995 through January 2024.


Find more information about our experience and outcomes treating complicated monochorionic twin pregnancies »

Resources for professionals

To better partner with you, the Center has created a number of professional-focused resources about TTTS (and other complicated twin pregnancies), as well as information you can share with your patients.

Twin-Twin Transfusion Syndrome: Making the Right Connections (Flip Chart)

TTS thumb This flip chart for healthcare professionals provides an overview of TTTS incidence, diagnosis, physiology and treatment options. Contact us to request a copy of this resource.

The CHOP cardiac scoring system

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 the patient's cardiac function scores before treatment, 24 hours after the procedure and at the patient's one-week follow-up appointment to determine the response to the intervention.

In Utero Insights Newsletter

The twin-twin transfusion syndrome edition of In Utero Insights, the Center's newsletter to healthcare professionals, includes information on how the Center supports families with TTTS from evaluation through follow up, sonography of complicated monochorionic twin pregnancies, research updates and more.

Case studies

The following case studies examine the implications and outcomes of specific diagnoses in complicated monochorionic pregnancies:

Resources you can share with patients 

Condition content

The Center has detailed diagnosis-specific information about TTTS, sIUGR, and TRAP written for families.

TTTS video

Lives in the Balance: Understanding Twin-Twin Transfusion Syndrome, an educational DVD created by the Center for clinicians and patient families, provides updated information on treatment protocols and the exclusive CHOP Cardiac Scoring System.

To request a copy, call 1-800-IN-UTERO (1-800-468-8376) or complete our online contact form.   

Recent publications on CHOP's twin experiences

Our team members have written extensively about the management of pregnancies with complicated multiples. Find a full list of publications about complex twin pregnancies authored by our team.

Screenshot of CFDT tour video

Tour our Fetal Center

Watch this video tour to learn what to expect at your first visit to the Wood Center for Fetal Diagnosis and Treatment.

Pregnant Mom and Child

What to Expect

From the moment of referral through delivery and postnatal care, your family can expect a supportive experience when you come to us with a diagnosis of a birth defect.