Related Experiment Video
Updated: Feb 5, 2026

Isolation of Primary Human Decidual Cells from the Fetal Membranes of Term Placentae
Published on: April 30, 2018
Unexpected finding of uniparental disomy mosaicism in term placentas: Is it a common feature in trisomic placentas?
Diane Van Opstal1, Karin E M Diderich1, Marieke Joosten1
1Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, The Netherlands.
Objective:
Non-invasive prenatal testing (NIPT) detects placental chromosome aberrations. When amniocentesis reveals a normal karyotype, confined placental mosaicism (CPM) may be assumed. In order to confirm this, placental cytogenetic studies were performed.
Method:
NIPT was conducted in the course of the Dutch TRIDENT study. Placentas of 10 cases with NIPT results indicating an autosomal trisomy and showing a normal (N = 9) or low mosaic karyotype (N = 1) in amniotic fluid (AF) were investigated. The cytotrophoblast as well as the mesenchymal core of two to four placental chorionic villi biopsies were studied with single nucleotide polymorphism (SNP) array. Clinical outcome data were collected.
Results:
In 10/10 cases, CPM was proven. In 3/10 cases trisomy/uniparental disomy (UPD)/biparental disomy (BPD) mosaicism was discovered. In 2/3 cases, all three cell lines were present in the placenta, whereas BPD was found in AF. In 1/3 cases trisomy 22/UPD22 was present in AF while trisomy 22/BPD22 mosaicism was found in the placenta. Five of 10 pregnancies were affected with pre-eclampsia, low birth weight, preterm delivery, and/or congenital malformations.
Conclusion:
The presence of trisomy/UPD/BPD mosaicism in 3/10 cases that we investigated proves that trisomic zygote rescue may involve multiple rescue events during early embryogenesis. UPD mosaicism, when present in crucial fetal tissues, may explain the abnormal phenotype in undiagnosed cases.
Related Concept Videos
The Fluid Mosaic Model
Common Ion Effect
Fluid Mosaic Model
Finding the Center of Gravity
Long-term Depression
Respiratory System Abnormal Finding I: Inspection and Percussion
Inspection Findings
During an inspection, several findings may suggest the presence of respiratory distress or disease. Pursed-lip breathing, where exhalation is slowed by...

