Prenatal sonographic features of triploidy at 12–16 weeks

Objective: The purpose of our study was to describe the sonographic appearance of triploidy in early pregnancy. Methods: We report the sonographic characteristics of a cohort of fetal triploid cases detected at targeted ultrasonographic vaginal examinations between 12 and 16 weeks of gestation from 2008 to 2014. Indications for fetal karyotype following ultrasound were maternal request, advanced maternal age, increased nuchal translucency, and/or fetal abnormalities. Results: Triploidy was detected in 25 cases during the 6 years of the study period with an estimated incidence of ~1 in 5000 pregnancies. Four cases had molar changes in the placenta. Among the remaining 21 cases, a consistent sonographic pattern was noted, which included the combination of asymmetric growth restriction with abdominal circumference lagging 2 weeks behind head circumference in 21/21, oligohydramnios in 20/21, abnormal posterior fossa or enlarged fourth ventricle in 20/21, and absent gall bladder in 17/21. Other findings present in more than 50% of cases included cardiac (70%) and renal (55%) abnormalities, clenched hands (55%), and hypoplastic lungs (67%). Conclusion: Fetal triploidy can manifest at 12–16 weeks with molar changes in the placenta or with a cluster of unusual sonographic findings whose presence should prompt appropriate testing for diagnosis in early pregnancy.