N-Terminal Pro-brain Natriuretic Peptide and Cardiovascular Adaptations in Monochorionic Diamniotic Twins

Abstract

Monochorionic diamniotic pregnancies are associated with adverse perinatal outcomes, including neonatal death and handicaps. Additionally, postnatal circulatory collapse has been suggested to be associated with a poor perinatal outcome, but this has not been fully investigated. We have assessed postnatal cardiac adaptations of monochorionic diamniotic twins by measuring N-terminal pro-brain natriuretic peptide, a precursor of brain natriuretic peptide. We observed the following findings. First, monochorionic diamniotic twins with twin-to-twin transfusion syndrome show an increased cardiac load at birth, and they require complete intensive care for both twins for postnatal circulatory collapse, which is alleviated by fetoscopic laser photocoagulation. Second, monochorionic diamniotic twins with selective intrauterine growth restriction show mildly increased cardiac load at birth compared with twin-to-twin transfusion syndrome, and most require intensive care for both twins because of poor cardiovascular adaptations. Third, the reason for the increased cardiac load in these monochorionic diamniotic twins is unbalanced blood transfusion via intertwin vascular anastomoses, as shown by a comparative study between monochorionic diamniotic and dichorionic diamniotic twins with selective intrauterine growth restriction. Further study is necessary to determine other high risk monochorionic diamniotic twin groups. Additionally, a novel therapeutic strategy, including fetal therapy, is mandatory to prevent postnatal cardiovascular collapse in monochorionic diamniotic twins.