Prenatal diagnosis of triploidy in second trimester of pregnancy: a series of 4 cases over an eleven-year period

Triploidy is a numerical chromosomal anomaly characterized by the presence of three sets of haploid chromosomes. The incidence is hard to evaluate, because usually it causes 1st trimester miscarriage. At 20 weeks of amenorrhea the incidence of triploidy is estimated at 1/250,000 cases. We present 4 cases of triploidy diagnosed during the decade 2003-2013 in the Prenatal Diagnosis Department of Maternity “Cuza-Vodă” Iasi, Romania, all registered in one year. The analysis of pathological cases identified in the last 11 years by prenatal diagnosis has shown that triploidies represented only 5.7% of numeric chromosomal anomalies, but in 2013 the four cases of triploidy represented 36% of numeric chromosomal anomalies. The karyotypes were recommended after discovering different congenital anomalies by ultrasound scan. In all cases, an intrauterine growth retardation (IUGR) was present but with no placental changes. Also, we discovered anomalies of limbs, congenital anomalies of heart and some dysmorphic features. This series demonstrates that triploidy may be discovered in the 2nd trimester of pregnancy and has a heterogeneous aspect at ultrasound scan, which can generate diagnostic difficulties. Therefore, the detection by ultrasound scan, at 18-22 weeks of pregnancy, of complex foetal morphological abnormalities should be an important reason for amniocentesis to search chromosomal anomalies.