The fetal brain in co-twins treated for twin-twin transfusion syndrome
File(s)
Author(s)
Taylor-Clarke, Marisa
Type
Thesis
Abstract
Introduction :
Twin-twin transfusion syndrome (TTTS) affects 10% of monochorionic pregnancies and provides a unique opportunity to study the impact of early environmental discordance in genetically identical twins. TTTS can be successfully treated with laser therapy but poor long term neurodevelopmental outcome remains a significant problem. Aberrant antenatal brain development may contribute to some of these deficits. The main aim of this study was to investigate differences in fetal brain development in identical twins treated for twin-twin transfusion syndrome.
Methods :
Thirty-nine twin pairs that had been treated by laser for TTTS underwent fetal MRI (1.5T) from 21 to 32 weeks gestational age. Volumetric segmentation of the fetal body was performed on 2D images whilst volumetric analysis of the supratentorial brain was performed on 3D reconstructed datasets. Development of the cortical surface was evaluated using an objective cortical scoring system. The metabolic profile of the fetal brain was assessed using magnetic resonance spectroscopy. Neurodevelopmental outcome was assessed at 1 and 2 years of age in surviving children.
Results :
Ex-donor fetuses had significantly smaller brains than their ex-recipient co-twins and showed evidence of global brain sparing. Extracerebral fluid volumes were significantly smaller in ex-donors relative to ex-recipient fetuses. Corrected cerebellar and cortical grey matter volumes were similar within twin pairs whereas maturation of the parieto-occipital fissure, central sulcus and Sylvian fissure was delayed in ex-donors compared to ex-recipients. Lactate was detected in 43% of fetal brains. By two years of age 20.8% of children followed up had significant neurodevelopmental impairment. This correlated with cortical maturation discordance within twin pairs.
Conclusions :
Significant differences in brain development exist between co-twins following laser treatment for TTTS. Discordance between twin fetuses correlates with later neurodevelopmental delay. Despite treatment and the absence of overt brain injury, in utero blood flow and endocrine influences may create divergent developmental paths in identical twins.
Twin-twin transfusion syndrome (TTTS) affects 10% of monochorionic pregnancies and provides a unique opportunity to study the impact of early environmental discordance in genetically identical twins. TTTS can be successfully treated with laser therapy but poor long term neurodevelopmental outcome remains a significant problem. Aberrant antenatal brain development may contribute to some of these deficits. The main aim of this study was to investigate differences in fetal brain development in identical twins treated for twin-twin transfusion syndrome.
Methods :
Thirty-nine twin pairs that had been treated by laser for TTTS underwent fetal MRI (1.5T) from 21 to 32 weeks gestational age. Volumetric segmentation of the fetal body was performed on 2D images whilst volumetric analysis of the supratentorial brain was performed on 3D reconstructed datasets. Development of the cortical surface was evaluated using an objective cortical scoring system. The metabolic profile of the fetal brain was assessed using magnetic resonance spectroscopy. Neurodevelopmental outcome was assessed at 1 and 2 years of age in surviving children.
Results :
Ex-donor fetuses had significantly smaller brains than their ex-recipient co-twins and showed evidence of global brain sparing. Extracerebral fluid volumes were significantly smaller in ex-donors relative to ex-recipient fetuses. Corrected cerebellar and cortical grey matter volumes were similar within twin pairs whereas maturation of the parieto-occipital fissure, central sulcus and Sylvian fissure was delayed in ex-donors compared to ex-recipients. Lactate was detected in 43% of fetal brains. By two years of age 20.8% of children followed up had significant neurodevelopmental impairment. This correlated with cortical maturation discordance within twin pairs.
Conclusions :
Significant differences in brain development exist between co-twins following laser treatment for TTTS. Discordance between twin fetuses correlates with later neurodevelopmental delay. Despite treatment and the absence of overt brain injury, in utero blood flow and endocrine influences may create divergent developmental paths in identical twins.
Version
Open Access
Date Issued
2015-11
Date Awarded
2017-02
Advisor
Rutherford, Mary
Gardiner, Helena
Wimalasundera, Ruwan
Bennett, Phillip
Sponsor
Tiny Tickers
Publisher Department
Department of Surgery & Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)