P44.03: 3D/4D diagnosis of Beckwith‐Wiedeman Syndrome in a fetus with an elevated alpha‐fetoprotein (AFP) level at the second trimester maternal serum screening

Abstract

Beckwith-Wiedeman Syndrome (BWS) is a rare genetic overgrowth disorder associated with various fetal structural anomalies. It affects approximately 1/14000 births. More frequent fetal features are macrosomia, abdominal wall defect, macroglossia, visceromegaly and associated polyhydramnios. In affected child a few case reports describe elevated alpha-fetoprotein (AFP) levels related to hepatoblastoma or mesenchymal hamartoma of the liver. A thirty-year-old patient, gravida 3, para 2, was referred to our unit at 34 weeks + 5 days gestation, for fetal macrosomia. The scan confirmed a macrosomic fetus and a 3D/4D scan of the fetal face showed a protruding macroglossia and a fixed opened mouth caused by an increased tongue thickness. Hepatomegaly, nephromegaly, cardiomegaly and polyhydramnios were visualized. The patient had performed a second trimester maternal serum screening, giving a Down Syndrome risk of 1 : 6085 and an elevated AFP level (3.05 MoM). On the basis of ultrasound scan a BWS was suspected. A female newborn was delivered by Cesarean section at term. Clinical evaluation of the neonate confirmed the prenatal features and BWS. The liver scan revealed hepatomegaly with no evidence of liver tumors. AFP was checked after birth and remained elevated. A surgical tongue reduction was performed. Follow-up at 12 months confirmed elevated AFP levels without evidence of liver tumors. Prenatal diagnosis of BWS is important to prevent hypoglycemia that occurs in 30-50% of affected neonates. In our experience when an elevated second trimester serum AFP is associated with fetal macrosomia at the twenty weeks scan a BWS should be included in the possible diagnosis. 3D/4D ultrasound evaluation of fetal face and tongue may be useful in the visualization and definition of macroglossia and viscera size. Elevated serum AFP level in fetuses affected by BWS is not always associated with liver tumors and therefore more causes should be searched for this feature.Beckwith-Wiedemann Syndrome (BWS) is a common genetic overgrowth syndrome. The syndrome was first described by Beckwith in 1963 and Wiedemann in 1964. Anterior abdominal wall defects, macroglossia and gigantism are considered the characteristic diagnostic triad of BWS findings. Although most cases appear to be sporadic (85%), the etiology of BWS is generally accepted as genetic. Present evidence supports autossomal dominant inheritance of BWS, with reduced penetrance and variable expressivity that may relate to the effects of genomic imprinting. It is estimated the BWS worldwide frequency is estimated at 1 in 13 700 live births. No sex or race predilection exists. Incidence is higher in infants produced with in vitro fertilization. We reported a case of a 32-year-old woman, primigravida, with fetal diagnosis of BWS in the second trimester of pregnancy. A bidimensional ultrasound scan showed a large anterior abdominal wall cyst, macroglossia and polycystic kidneys. Visceromegaly, a large to age fetus (over 95 th percentile) and increased placental size (almost twice the ...