Triploid pregnancy-Clinical implications

Clin Genet. 2021 Oct;100(4):368-375. doi: 10.1111/cge.14003. Epub 2021 Jun 1.


Triploidy is a life-limiting genetic aberration resulting from an extra haploid set of chromosomes of paternal (diandric triploidy) or maternal origin (digynic triploidy). Triploidy affects around 1%-2% of all conceptions. The majority of cases is miscarried at early developmental stages. In consequence of genomic imprinting, parental origin affects the phenotype of triploid pregnancies as well as the prevalence and spectrum of related maternal complications. Distinctive ultrasound features of both triploid phenotypes as well as characteristic patterns of biochemical markers may be useful in diagnosis. Molecular confirmation of the parental origin allows to predict the risk of complications, such as gestational trophoblastic neoplasia, hyperthyroidism, hypertension, or preeclampsia associated with the paternal origin of triploidy. Diagnosis of partial hydatidiform mole associated with diandric triploidy is challenging especially in the first trimester pregnancy loss due to the limitations of both histopathology and ultrasound. We present important clinical aspects of triploid pregnancies and indicate unresolved issues demanding further studies.

Keywords: diandric triploidy; digynic triploidy; gestational trophoblastic neoplasia; maternal triploidy; partial hydatidiform mole; paternal triploidy.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Abortion, Spontaneous / genetics*
  • Chromosome Disorders / diagnosis*
  • Chromosome Disorders / epidemiology
  • Chromosome Disorders / genetics*
  • Female
  • Fetal Growth Retardation / genetics
  • Genetic Testing
  • Genomic Imprinting
  • Humans
  • Hydatidiform Mole / diagnosis
  • Hydatidiform Mole / genetics
  • Phenotype
  • Pregnancy
  • Prenatal Diagnosis
  • Prevalence
  • Recurrence
  • Triploidy*
  • Ultrasonography, Prenatal