Conservative management in a case of uncomplicated trap sequence: a case report and brief literature review

Abstract

Introduction: twin reversed arterial perfusion (TRAP) sequence is a rare anomaly that occurs in monochorionic twins with overall mortality rate ranging from 50% to 70% in the normal fetus, above all for congestive cardiac failure. Case report: a 31-year-old Caucasian gravida was referred to our fetomaternal medicine unit in the 25 gestational age. Ultrasound examination revealed a monochorionic, biamniotic twin pregnancy with a donor fetus showing normal morphology and growth corresponding to gestational age. The recipient twin appeared grossly abnormal with no head, upper limbs, heart, or thoracic structures and massive, diffuse, soft tissue edema. Fetal Doppler and fetal echocardiography revealed normal parameters. The patient refused any treatment and was monitored with weekly ultrasonography and Doppler ultrasound examination. She underwent cesarean section due to premature labor/rupture of membranes secondary to a mild polyhydramnios, at 36 weeks gestational age and delivered an apparent normal female live baby weighing 2550 gr, and another female acardius acephalus twin, birth weight 1300 gr. This baby had rudimental edematous lower limbs, pelvic bone, lower sacral vertebrae, and absence of thorax and cephalic structures. Conclusion: although the literature suggest that early intrafetal laser treatment of TRAP sequence is advantageous, our case shows that pregnancies referred late would still require a tailored approach after a risk-benefit assessment.

Misdiagnosis of an Acardiac Twin in the First Trimester, A Case Report.

“…Larger studies are necessary to examine the best timing for preventive intervention with the higher pump twin survival. [2] In our case, the patient was diagnosed late in pregnancy (25 weeks), at the time she was referred to us we adopted an expectant management with weekly ultrasound surveillance, because of the higher risk of preterm delivery after treatment in late gestational age. No polyhydramnios, signs of cardiac failure or fetal hydrops in the pump twin were identified.…”

“…This high cardiac output also increases perfusion of the fetal kidneys, resulting in overproduction of fetal urine and polyhydramnios, at risk of premature delivery. [2] The perinatal mortality rate for pump twin without treatment is high, around 55%, due to heart failure and preterm delivery. [4] After in utero therapy, the survival rate of the pump twin increases to 80-90%.…”

“…A higher weight of the recipient twin is more likely associated with cardiac insufficiency and perinatal mortality of the pump twin. [2] When the ratio of the weight of the acardiac twin to the weight of the pump twin is greater than 70%, the risk of preterm delivery is 90%, and of congestive heart failure in the pump, twin is 30%. In comparison, when the ratio is less than 70% the corresponding risks are 75% and 10%, respectively.…”

“…[2] Current, minimally invasive in utero interventions, to occlude vascular supply to the acardiac twin, can be performed through two modalities: extra-fetal (intertwine anastomosis or umbilical cord occlusion) and intra-fetal circulation. Occlusion of the umbilical cord of the acardiac twin can be performed through a fetoscope by laser or bipolar coagulation.…”

“…Four distinct morphological types have been described in literature: acardius acephalous: is the most common type (60-75%), with developed pelvis and lower limbs, may have arms, but thoracic organs and head are absent; acardius anceps: the most differentiated type of acardiac twins with established body and extremities, but only a partially formed head and face (20%); acardius acormus: in which only cephalic structures were detectable, is a sporadic type (10%); acardius amorphous: consists of a shapeless mass of tissue containing no recognizable human structures (5%). [2] CASE REPORT:…”