We evaluated triploid pregnancy to determine whether there are clinically important differences between the three karyotypes: 69,XXX, 69,XXY, and 69,XYY. Prospectively maintained cytogenetic databases at five tertiary care centers were retrospectively reviewed over a 10-year period to identify all triploid pregnancies. Targeted ultrasounds were reviewed to identify fetal and placental findings. Sonographic findings were compared by karyotype. There was a total of 549 triploid gestations; preimplantation genetic diagnosis (PGD) detected 413 triploid embryos, and the cytogenetic databases provided 136 clinical pregnancies with triploidy. In triploid embryos with PGD, the frequency of the 69,XYY karyotype was 8.7% (36/413), compared with 0.74% (1/136) during the first trimester of clinical pregnancies (p = 0.002). In clinical pregnancies, 60% (36/60) of 69,XXY fetuses survived the first trimester of development compared with 69% (52/75) of 69,XXX fetuses (p = NS). No clinically important differences were observed between 69,XXX and 69,XXY karyotypes in terms of type, number, or severity of fetal or placental anomalies. Gestations with a 69,XYY karyotype are found less frequently compared with gestations with a 69,XXX or 69,XXY karyotype. The decline in fetal survival of the 69,XYY triploid karyotype needs further investigation. There are significant abnormalities detected during prenatal sonography in most all clinically recognized cases of triploidy. Sonography cannot reliably distinguish between the 69,XXY and 69,XXX karyotypes.
Thieme Medical Publishers.