A case of triploidy detected by crosstrimester test.

A 40-year-old woman presented in her second pregnancy, naturally conceived. Maternal serum screening and ultrasound examination raised concerns regarding aneuploidy. After genetic counselling an amniocentesis was performed, showing a 69,XXX karyotype.Here we report a case of digynic triploidy, which resulted from fertilization of a diploid ovum by a single sperm.