Selective intrauterine growth restriction in monochorionic twins: pathophysiology, diagnostic approach and management dilemmas.

Objective: Selective intrauterine growth restriction (sIUGR) in monochorionic (MC) twins is associated with a substantial increase in perinatal mortality and morbidity for both twins. Clinical evolution depends on the combination of the effects of placental insufficiency in the IUGR twin with inter-twin blood transfer through placental anastomoses. Case 1: It is about a 30 years old women with a Spontaneous monochorionic twin pregnancy. A selective intrauterine growth restriction type 2 was diagnosed at 22 WA with a persistent absent diastolic flow in the umbilical Doppler of the twin with IUGR. The evolution was marked by the deterioration of the Doppler waveforms and the appearance of a reversed end-diastolic flow at 29 WA. Then, because of the faltering growth and the appearance of A reverse atrial flow in the Ductus venosus, a cesarian section was performed at 32 WA. Birth weights were respectively 1200gr and 1800gr for the twin with IUGR and the larger twin. The latest died of a hyaline membrane disease after 5 days. Case 2: It is about a Spontaneous monochorionic diamniotic twin pregnancy with a diagnosis of a type 2 sIUGR at 26 WA. Monitoring was regular and based on the study of fetal growth, and Doppler waveforms. The evolution was marked by a persistent absent diastolic flow in the umbilical Doppler of the twin with sIUGR and the conservation of growth in both twins. Delivery was scheduled at 34 WA. The birth weights were of 1300g and 1700g. At the age of 6 mouths, the pediatric exam did not revealed any brain injury for both twins. Conclusion: SIUGR is a common condition associated with MC pregnancy. It is increasingly considered to be an important complication of MC twins, with potentially significant risks of intrauterine fetal demise or neurological adverse outcome for both twins. Introduction of skilled sonographic evaluation, a better understanding of different Doppler patterns and of the anatomy of MC placenta, together with the development of fetoscopic techniques have all contributed to a deeper scientific understanding of this condition. [ABSTRACT FROM AUTHOR]