OP25.03: Effects of hypoxia on plasma amino acids and taurine of ovine fetuses in comparison to cerebral blood flow using 3D colour Doppler imaging

Abstract

Conclusions: These data strongly support the need for a more detailed exploration of hsp60 mRNA levels in maternal circulation with the view toward routine assessment into everyday practice, and recognition as potential non-invasive biomarker for placental insufficiency related pregnancy complications. OP25.03Effects of hypoxia on plasma amino acids and taurine of ovine fetuses in comparison to cerebral blood flow using 3D colour Doppler imaging Objectives: To assess the impact of changes in systemic venous returns (decreased inferior vena cava and relative increase in superior vena cava flows) on respective ventricular performances and O 2 transport to the brain. Methods: In this prospective multicenter study, the aortic Isthmic Systolic Index (ISI = systolic nadir divided by the peak velocity of the waveform) and the Isthmic Time Systolic Index (ITSI = duration of systolic reverse flow divided by the total time of systolic ejection) were measured weekly in a cohort of growth restricted fetuses and compared to a population of normals. Pulsatility indices of the umbilical (UPI) and middle cerebral arteries (MCAPI) were also calculated. Data were analyzed by ANOVA for mean comparison and partial correlations, corrected for gestational age using SPSS 20.0. Results: Sixty-two (62) IUGR fetuses between 24 and 37 weeks of gestation were compared to a population of normals, matched for gestational age. The systolic nadir of the AoI started to be retrograde at 26w in the IUGR group, compared to 31w in the normals. From 29w, the ISI became significantly lower in the IUGR group (F = 9.61, p = 0.021); this difference remained significant up to 32w. The ITSI was significantly correlated to the MCAPI (r = −0.36, p = 0.008). Conclusions: With the appearance of a reverse flow in the isthmus of IUGR fetuses, the brain is partly perfused by poorly oxygenated red cells turning in circle, both in systole and diastole. From the aortic isthmus towards aortic arch, brain, superior vena cava, right atrium and ventricle, ductus arteriosus and back to the isthmus, without the benefit of passing through the placenta. The relation between this ''isthmic-brain hypoxic circle'' and the incidence of abnormal post-natal neurodevelopmental sequellae deserves further investigations.This investigation (Placental Insufficiency and Aortic isthmus flow, The PIAF study) was supported by a research grant from the Canadian Institute for Health Research (CIHR); grant#MOP-97986. OP25.05Corpus callosum differences assessed by MRI in term small for gestational age fetuses and its association with neurobehaviour G. Egaña-Ugrinovic, M. Sanz-Cortes, C. Couve-Pérez, F. Figueras, E. Gratacós Maternal Fetal Medicine, Hospital Clinic: Universitat de Barcelona, Barcelona, Spain Objectives: To evaluate corpus callosum (CC) morphometry by MRI in term small for gestational age (SGA) fetuses compared to controls and its association with neurobehavioral outcome. Methods: 117 SGA and 73 control fetuses with normal umbilical Doppler were imaged using a 3T MRI sca...