Dandy-Walker Variant in A Fetus of an ICSI Twin Gestation: A Case Report

The incidence of fetal chromosomal or structural abnormalities after assisted reproductive treatment (ART) is one of the most intriguing topics. Specifi cally, the central nervous system anomaly rate was found to be 0.7% in fetuses and children conceived after ICSI, which is statistically similar to spontaneous conceptions (1). A partial or complete cerebellar vermian defect may occur sporadically or as a component of the Dandy-Walker syndrome (DWS), Down syndrome or Joubert Syndrome (2). The Dandy-Walker malformation (DWM), Dandy-Walker variant (DWV), and mega cisterna magna (MCM) seem to represent steps on a continuum of developmental anomalies of the posterior fossa (3). Therefore, the Dandy-Walker complex (DWC) was suggested to be used to describe this continuum of aberrant development of the posterior fossa that might be associated with multiple congenital anomalies and radiographic abnormalities (3). DWC is a rare abnormality of the central nervous system (CNS), usually observed during the prenatal period or early infancy. In a population-based study of posterior fossa anomalies, the incidence of DWM/V was reported to be 1/11574 births (4). On the other hand, in a recent study, DWM was reported to be relatively common, the incidence was given as 1 in 2500-3500 live births with a slight female predominance (5). DWV forms one part of the spectrum of DWC and is a less severe posterior fossa anomaly than the classic DWM, however it might be associated with both extra-and intracranial anomalies with or without chromosomal abnormalities. The outcome is grim for DWM/V in the presence of concurrent anomalies (4). However, isolated DWV was reported to have a good developmental outcome (6). Previous studies reported additional fetal extracranial anomalies to be seen in 65% of DWV cases (7, 8). In a recent study evaluating associated anomalies in a case series of 24 pediatric patients with DWV, concurrent anomalies included cardiac (42%), gastrointestinal (21%), orthopedic (13%), and genitourinary (13%) abnormalities (6). Ventriculomegaly also has been reported to be one of the most common (27%) concurrent intracranial anomalies detected sonographically in DWV cases (9). With this report we presented a DWV case in a pregnancy achieved with ART. To our knowledge, this is the fi rst reported case of a DWV in a pregnancy conceived through ICSI.