Triploidy is the most common chromosomal abnormality in human conceptions that cause fetal loss before 20 weeks of gestation and has an incidence of 1 in 10,000 live births. Placental changes, fetal malformations and intrauterine growth retardation (IUGR) occur in triploid pregnancies. We performed karyotype analyses of 75 spontaneous abortions and 1,114 amniotic fluid cultures by conventional methods between 2002 and 2005 at our cyto genetics laboratory. Triploidy was detected in five spontaneous abortions and four amniotic fluid samples. Abortions were between the 9th and 13th weeks of pregnancy, and cytogenetic analyses revealed a 69,XXY karyotype in four of the aborted fetuses and a 69,XXX karyotype in one. Amniotic fluid cell cultures revealed a 69,XXX karyotype in three cases and 69,XXY in one. Amniocentesis was performed in four patients because of an increased trisomy 18 risk detected in maternal serum screening. In pregnant women undergoing second trimester amniocentesis, increased risk for trisomy 18 may be due to triploidy and should be taken into account during genetic counseling.

Key words: Triploidy, Maternal serum screening, Cytogenetics, Pregnancy