288 Assessing in vivo placental function in pregnancies complicated by maternal diabetes mellitus

Abstract

We sought to examine fetal brain and placental response to maternal hyperoxia using blood oxygen level–dependent (BOLD) magnetic resonance imaging (MRI) in pregnancies complicated by diabetes mellitus (DM). This is a single center prospective case control cohort study of women with singleton gestations, at least 18 weeks or greater. Cases include women diagnosed with either pre-gestational or gestational DM. Controls include healthy pregnancies without any comorbidities. Gradient-echo planar and fast spin-echo T2 weighted imaging was performed with a maternal hyperoxia paradigm of 2 minutes resting state baseline (RS), 6 minutes maternal hyperoxia (HO) of 100% oxygen via a non-rebreather and 5.6 minutes post oxygenation for return to resting state (RR). Analyses were performed at one minute time intervals to assess the change in R2* from baseline (ΔR2*). Student’s t-test was performed to compare outcomes between groups. Of the 113 women recruited, 67 (59.3%) healthy controls with mean gestational age (GA) in weeks 30.9 ± 4.3, and 46 (40.7%) cases, mean GA 30.2 ± 4.5. Of the cases 13 (28.26%) had Type 1 DM, 15 (32.61%) were diagnosed with Type 2 DM, 17 (36.96%) had Gestational (G) DM and 1 (2.17%) subject never disclosed the diabetes diagnosis. Overall, results were similar between groups during HO. During RR minutes 4 and 5, the ΔR2 (difference in oxygen signal relative to baseline), was lower in the diabetic cohort compared to controls, with most significant decrease in T1DM (RR6) and T2DM (RR2, RR4) (Fig 1&2). Metabolic, inflammatory and vascular changes have been described in ex vivo placentas from diabetic pregnancies. Maternal hyperoxia during BOLD imaging reflects oxygen carrying capacity and transfer from the maternal circulation to the placenta and fetus. Decreased BOLD signaling suggests altered placenta function, reflecting either increased oxygen consumption of the diabetic placenta or continued oxygen transfer to the fetus. Additional studies to explore the clinical significance of these findings are underway.View Large Image Figure ViewerDownload Hi-res image Download (PPT)