Abstract

Characteristic recipient and donor twin phenotypes occur in twin-twin transfusion syndrome (TTTS). Following successful fetoscopic laser ablation (FLAP), overt features of TTTS resolve. Our aim was to investigate whether differences in brain growth and development exist between ex-recipient and ex-donor twins after successful treatment.

35 MCDA twins referred to our unit post FLAP underwent fetal brain MRI according to our local protocol. Snapshot MRI with Volume Reconstruction (SVR) was used to create 3D volume datasets for semi-automatic tissue segmentation. Exclusion criteria were MRI abnormalities, post imaging intrauterine death, unknown outcome or images unsuitable for SVR. 10 ex-recipient / ex-donor matched pairs met criteria for calculation of whole brain tissue and ventricular volumes.

Median gestational age (GA) at MRI was 26.2 weeks (22.3–29) and median time since treatment was 40 days (22–72). Paired samples t-test showed no significant difference between ex-recipients and ex-donors for whole brain tissue volume (p=0.9) or ventricular volume (p=0.4). Whole brain tissue volume increased with GA (r2=0.88, p<0.0001) and grouped linear regression with covariance analysis showed no significant difference between our twin group, survivors of single intrauterine death and singleton controls for slope or separation. Ventricular volume was not related to gestational age (r2=0.09, p=0.2).

Whole brain tissue volumes are similar in ex-recipients and ex-donors following successful FLAP and comparable to singleton controls and single survivors of intrauterine death. Future work will investigate brain maturation indices, tissue microstructure and functional status in this group as well as in survivors of co-twin demise.