One case of increased intracranial translucency during the first trimester associated with the Dandy–Walker variant

Abstract

A 33-year-old multigravida was referred to our fetaltreatment center for early oligohydramnios at 11+2weeksof gestation. The examinations were performed using anAccuvix XG (Samsung Medison Co., Ltd, Seoul, Korea) with a2 to 6MHz transabdominal probe. The fetal size was compatiblewith the gestational age (crown –rump length (CRL): 45.4mm).Ultrasound showed IT enlargement of 3mm. We could notmeasure the nuchal translucency (NT) because of the smallamniotic sac. Follow-up ultrasound at 13+0weeks of gestationrevealed that the CRL was 71.7mm, the IT was still enlarged(3.7mm), and micrognathia was suspected (Figure 1). Theamniotic sac was becoming larger, and the NT was normal(1.1mm). Two weeks later, we performed amniocentesis forkaryotyping,andwhichyieldedanormalresult(46,XY).Thepatient was lost to follow-up until 23+2weeks of gestation.Ultrasonography showed hypoplasia of the cerebellar inferiorvermis without marked enlargement of the posterior fossa(Figure 2). No other abnormality of the central nervous systemwas observed. Retrognathia rather than micrognathia wassuspected. We counseled the parents regarding the prognosisand they decided to continue the pregnancy. Follow-upultrasound at 31+2weeks of gestation demonstrated the samefindings. The male infant was delivered vaginally at 39+0weeksof gestation, and bilateral cleft palates with retrognathia werenoted. Postnatal brain magnetic resonance imaging showedmild hypoplasia of the inferior cerebellar vermis with normalposterior fossa. The baby was doing well when seen for theone-month follow-up.