Case:

The twins (A and B, donor, and recipient) were delivered at 32 ^2/7 weeks of gestation.  The pregnancy was complicated by monochorionic diamniotic twinning with twin-to-twin transfusion syndrome (TTTS). Laser ablation was done after 27 weeks of gestation for the reason that fetus A (recipient) was noted to be hydropic. Follow-up after laser showed resolution of hydrops but persistent right ventricular abnormality with poor pulmonary blood flow.  At birth fetus A was noted to be small for gestational age with a birth weight of 1200 grams (z= -1.68). The infant required intubation in the delivery room and was placed on a ventilator at arrival at the NICU. The infant's oxygen saturation remained in the range of 82-90. Multiple echocardiograms were performed. His last echocardiogram is shown in Figure 1. The infant continued to remain critical despite the maximum ventilator support with 100% oxygen, inhaled nitric oxide 20 ppm, hydrocortisone, prostaglandin E, dobutamine, epinephrine milrinone, and vasopressin drips. On day 26 of life, he was coded and died despite all resuscitative efforts.

A, B and C showing dysplastic tricuspid valve (turbulent jet across the value) with moderate regurgitation, peak tricuspid valve gradient of 44mmHg (near systemic) and moderately hypertrophied right ventricle.

Discussion:

Multiple studies on twin-twin transfusion syndrome (TTTS) have shown the effect of TTTS on the receipt heart. ^1,2 These effects include both systolic and diastolic dysfunction with decreased shortening fraction predominantly of the right ventricle with tricuspid regurgitation. Antenatal treatment with selective fetoscopic laser photocoagulation has been shown to improve hemodynamic improvement in these cases. ³ Barrea et al ⁴ reported an acute improvement in the biventricular systolic function post-laser. However, in the case described, we did not notice any beneficial effect of laser on the fetus.

In TTTS, the receipt twins have an increased risk of cardiac failure, death, and long-term morbidities. ⁵ Gray et al ⁶ reported right heart abnormalities in 33% of the recipient twins. In their case series, two neonates had dysplastic tricuspid valves. Among the two, the preterm born at 31 weeks of gestation developed intractable heart failure and died on day 46. In our case, we supported the infant with multiple cardiac medications, inhaled nitric oxide, and maximum ventilatory support based on the suggested guidelines for the management of intractable hypoxemia and pulmonary hypertension. ⁷ The infant died on day 26. The parents refused an autopsy. A combination of prematurity, tricuspid valve dysplasia, right heart diastolic dysfunction, and ineffective antenatal laser ablation are probably the cause of his poor prognosis.

In conclusion, the case highlights the need for aggressive monitoring of TTTS cases and considering laser ablation earlier.

Conflict of Interest: None

Funding Source: None