Centro de Diagnóstico Pré-Natal, Hospital de D. Estefânia - Centro Hospitalar Lisboa Central. Lisboa, Portugal.
Problem Statement: Twin-twin transfusion syndrome (TTTS) is one of the most serious complications of monochorionic multiple gestations. It is associated with a high risk of fetal/neonatal mortality, especially in previable gestations, and fetuses who survive are at risk of severe cardiac, neurologic, and developmental disorders. Until now we have been able to diagnose it only when fully established, however, obstetric management might be more effective if TTTS could be detected earlier in pregnancy. Early (11 to13 week) markers: nuchal translucency (NT) and crown-rump length discrepancy and ductus venosus (DV) Doppler abnormalities may denote the risk for TTTS development allowing an early diagnosis and optimized management.
Methods: Case report of monochorionic biamniotic (MCBA) pregnancy with a first trimester marker for TTTS.
Results: 31-year-old, OI 0-1-0-1, with a MCBA spontaneous twin pregnancy. Ultrasound at 11+3 weeks reveled NT discrepancy: fetus A - CRL 46mm, NT > 95th percentile and fetus B – CRL 47mm, NT in the 50th percentile. Chorionic villus sampling at 12 weeks reveled normal 46,XY karyotype. At 17 weeks Quintero stage II TTTS was diagnosed and at 18+0 weeks, with Quintero stage IV, fetoscopic laser photocoagulation of placental anastomoses was successfully performed. Follow-up ultrasound at 18+6 weeks – donor: 175g, visible bladder, oligohydramnios, normal DV Doppler; recipient: 223g, mild ascitis and pericardic effusion, polyhydramnius, reverse A wave in DV. Favorable evolution for both fetuses proceeded until 32+4 weeks when selective growth restriction of the ex-recipient fetus was diagnosed. At 33+4 weeks, due to deterioration of fetal well-being whith oligohydramnius and abnormal Doppler study, caesarean section was performed: fetus 1 (ex-donor) male, 1148 g, Apgar Index: 9/10; fetus 2 (ex-receptor) male, 1264 g, Apgar Index: 9/10. Favorable neonatal evolution for both twins, but at 9 M of age, sudden death of the ex-donor fetus occurred.
Conclusion: TTTS is a serious complication in MC pregnancies with severe morbidity associated and ultimately resulting in loss of one or all fetuses. Screening for TTTS markers at 11-13 weeks scan may allow its diagnosis at early stages improving the prognosis for both fetuses.