Annotated References Donepudi R, Mann LK, Wohlmuth C, et al Recipient umbilical artery elongation (redundancy) in twin-twin transfusion syndrome Am J Obstet Gynecol 2017;217(2):206 [e1– e11] The usual 1:1 coiling relationship between the paired umbilical arteries and single umbilical vein in the umbilical cord is altered in the setting of fetal hypertension The hypertensive recipient fetus shows redundancy of the arteries and hypercoiling in response to altered fetal hemodynamics Haidar ZA, Papanna R, Sibai BM, et al Can 3dimensional power doppler indices improve the prenatal diagnosis of a potentially morbidly adherent placenta in patients with placenta previa? Am J Obstet Gynecol 2017;217(2):202 [e1–e13] The technology described in this paper uses new developments to assess organ perfusion Application of power Doppler to a threedimensional volume set using virtual organ computer-aided technology (VOCAL) creates a measurement of organ perfusion by comparing the percentage of colored voxels to total voxel count within an organ Lauridsen MH, Uldbjerg N, Henriksen TB, et al Cerebral oxygenation measurements by magnetic resonance imaging in fetuses with and without heart defects Circ Cardiovasc Imaging 2017;10(11):e006459 New MRI techniques provide more information on brain oxygen delivery in fetuses with congenital heart defects Leung V, Avnet H, Henry A, et al Automation of the fetal right myocardial performance index to optimise repeatability Fetal Diagn Ther 2018;44(1):28–35 Reproducibility is generally low in assessment of the fetal myocardial performance index Automation of the process reduces interobserver error and may increase the clinical utility of this measurement Nwogu LC, Moise KJ Jr, Klein KL, et al Successful management of severe red blood cell alloimmunization in pregnancy with a combination of therapeutic plasma exchange, intravenous immune globulin, and intrauterine transfusion Transfusion 2017 [Epub before print] Fetal anaemia is suspected by elevated velocities in the middle cerebral artery Intrauterine transfusion is life-saving and latterly combined with immune globulin provides effective new treatment options Seed M In utero brain development in fetuses with congenital heart disease: another piece of the jigsaw provided by blood oxygen leveldependent magnetic resonance imaging Circ Cardiovasc Imaging 2017;10(11):e007181 The contribution of oxygen delivery in brain development of fetuses with congenital heart defects is discussed Szwast A, Putt M, Gaynor JW, et al Cerebrovascular response to maternal hyperoxygenation (MH) in fetuses with hypoplastic left heart syndrome (HLHS) depends upon gestational age (GA) and baseline cerebrovascular resistance Ultrasound Obstet Gynecol 2017 [Epub before print] Fetal arterial oxygen content may be increased by maternal hyperoxygenation This has been proposed as a prenatal test of pulmonary function and in this paper response is related to gestational age and baseline resistance Wohlmuth C, Moise KJ Jr, Papanna R, et al The influence of blood pressure on fetal aortic distensibility: an animal validation study Fetal