In a remarkable demonstration of advanced prenatal care, a rare and high-risk twin pregnancy known as Twin Reversed Arterial Perfusion (TRAP) sequence was successfully managed at Ankura Hospital, Bhubaneswar, under the expert care of Dr. Rama Manjari Naik, Fetal Medicine Specialist, resulting in a favourable outcome for the healthy twin.
TRAP sequence is an exceptionally rare condition. As explained by Dr. Naik, it occurs in approximately 1–2.6% of monochorionic twin pregnancies and in about 1 in 35,000 pregnancies overall.
Understanding the Condition
The case involved a monochorionic twin pregnancy- a condition in which two fetuses share a single placenta. In TRAP sequence, one twin—referred to as the Acardiac twin—develops without a functional heart and survives by drawing blood from the healthy pump twin through abnormal placental connections. This abnormal circulation places severe strain on the pump twin’s heart and, if left untreated, can lead to heart failure, preterm delivery, or fetal loss.
Early Detection and Diagnosis
“The condition was identified during a routine antenatal ultrasound, which revealed one normally developing fetus alongside a severely malformed fetus with no detectable cardiac activity. Detailed Doppler studies confirmed reversed blood flow between the twins, establishing the diagnosis of TRAP sequence,” explains Dr Rama Manjari Naik, Consultant Fetal Medicine at Ankura Hospital for Women and Children, Bhubaneswar, who diagnosed the condition.
Careful Counselling and Close Monitoring
Following comprehensive counselling, the parents were informed about the potential risks, prognosis, and available fetal therapy options for the acardiac twin, including radiofrequency ablation, laser coagulation, and bipolar cord occlusion. After careful consideration, the couple chose to continue the pregnancy with intensive medical supervision.
The pregnancy was then monitored weekly, with close assessment of fetal growth, amniotic fluid levels, and Doppler parameters. Particular attention was given to measuring the size of the acardiac twin, as it is a key indicator for predicting the risk of complications in the healthy twin that has a heart.
At 36 weeks and 4 days of gestation, Doppler abnormalities were detected, prompting a planned lower segment caesarean section (LSCS). The healthy twin was delivered safely.
Histopathological examination of the acardiac mass- the other twin- revealed the presence of cartilage, bone tissue, skeletal muscle, and overlying epithelium, thereby confirming its fetal origin and validating the antenatal diagnosis.
A Message of Hope
This case underscores the critical importance of early diagnosis, timely referral, and specialized fetal medicine care in managing rare and life-threatening pregnancy complications. Ankura Hospital for Women and Children has an established fetal medicine department equipped with advanced technology and experienced specialists, enabling access to sophisticated prenatal testing services in the state of Odisha.
“With advances in prenatal imaging and fetal therapy, outcomes that were once considered impossible are now achievable—offering renewed hope to families navigating complex and high-risk twin pregnancies,” concludes Dr Rama Manjari Naik.
Dr Rama Manjari Naik,
MBBS, MS (OBG), Trained in Fetal Medicine (BFMC) Bangalore
Consultant Fetal Medicine
Ankura Hospital, Bapujinagar, Bhubaneshwar
