Ultrasonographic findings and natural history of pregnancies diagnosed as fetal trisomy 18, trisomy 13, and triploidy

INTRODUCTION: The aim of this study was to investigate fetal ultrasonographic findings and perinatal outcomes in pregnancies with fetal trisomy 18, trisomy 13, and triploidy.
METHODS: Pregnancies diagnosed as fetal trisomy 18, trisomy 13, and triploidy at a tertiary center between January 2013 and January 2020 were included in the study. Maternal ages, gestational ages at the time of diagnosis, antenatal follow-ups, prenatal fetal ultrasonography reports, perinatal outcomes, whether the pregnancies resulted in live births, and the outcomes of the newborns were obtained.
RESULTS: A total of 104 cases (trisomy 18 [n=74, 71.2%], trisomy 13 [n=21, 20.2%], and triploidy [n=9, 8.6%]) were included in the study, and pregnancy was terminated in 79 (76.0%) of the cases. The most common anomaly was cardiac malformations in fetuses with trisomy 18 and triploidy, and central nervous system anomalies in fetuses with trisomy 13. Of 25 patients who preferred to continue the pregnancy, nine (36.0%) resulted in miscarriage and 13 (52.0%) resulted in fetal death. In all three pregnancies that resulted in live births, newborns died in the early neonatal period.
DISCUSSION AND CONCLUSION: Most fetuses with trisomy 18, trisomy 13, and triploidy have severe fetal malformations. In cases where the pregnancy is not terminated, the risk of fetal loss is high. Patients with the expectation of self-termination should be informed that this loss may not occur until the third trimester and that pregnancy may result in a live birth.