TRISOMY-13-SYNDROME - PRENATAL US FINDINGS IN A REVIEW OF 33 CASES

PURPOSE: To determine the type and prevalence of prenatal ultrasound (US) findings in fetuses with trisomy 13. MATERIALS AND METHODS: Prenatal US findings in 33 consecutive fetuses with trisomy 13 and in 200 karyotypically normal fetuses were reviewed and compared. RESULTS: One or more abnormalities were found in 30 fetuses (91%). Major anomalies detected by means of US included holoprosencephaly (13 [39%]) or other central nervous system anomalies (19 [58%]), facial anomalies (15 [48%]), and renal (11 [33%]) and cardiac (16 [48%]) defects. Growth retardation was also present in 16 (48%). Echogenic chordae tendineae were seen in 10 (30%), which includes seven (39%) of 18 fetuses examined before 20 menstrual weeks (compared with four [2%] of 200 fetuses in the reference group [P < .001]). Other findings not generally associated with trisomy 13 but present in this series included a large cisterna magna (six [18%]), mild cerebral ventricular dilatation (three [9%]), nuchal thickening or cystic hygroma (seven [21%]), and a hypoplastic left side of the heart (seven [21%]). CONCLUSION: Prenatal US can help detect one or more anomalies in most fetuses with trisomy 13; thus, US findings can indicate whether karyotype should be tested.