USA Surgery Today

More than any other variable, ultrasonography and its wide implementation has permitted the greatest gain in understanding of fetal malformations. Routine prenatal ultrasonography is currently generally performed between 16 and 20 weeks’ gestation as both a screen for congenital anomalies and, more broadly, for pregnancy dating and assaying fetal growth and well-being. From this experience, sonographic markers of fetal outcome and criteria for fetal intervention have been developed. Moreover, in many instances, this knowledge has allowed for more thorough informed counseling of women with pregnancies complicated by a fetal anomaly. Fetal echocardiography and pulsed Doppler interrogation of the fetal circulation provide valuable diagnostic information that often allows for a physiologic correlation to be derived for a recognized structural defect. In addition to its diagnostic utility, US is paramount to the success of any proposed fetal intervention. Guidance for percutaneous fetal interventions such as draining fetal effusions, fetal shunt placement, fetal vesicocentesis for obstructive uropathy, and the mapping of the placental position prior to open fetal surgery are just a few of the examples (1,2).

Out of a desire to gain ever more prease fetal anatomic detail, echo planar imaging or ultrafast MRI has emerged as an additional critical imaging modality (3). Complementary to fetal US, prenatal MRI has much more limited indications for its use, but can provide a more detailed assessment of fetal anatomy that translates into improved diagnostic accuracy in special circumstances (4). Ultrafast fetal MRI, which represents an evolution in technique to provide faster scan times, thus obviating the