Placental epigenetic clocks: estimating gestational age using placental DNA methylation levels.
Level 4 - case-series / case-control
Cross-sectional biomarker derivation and validation study using human placental tissue samples
PubMed 31235674 · doi:10.18632/aging.102049
What was done
The authors developed and validated epigenetic clocks specifically for placental tissue to estimate gestational age (GA) using placental DNA methylation (DNAm) data. Using a training dataset of 1,102 DNAm arrays, they constructed three models: a robust placental clock (RPC) unaffected by common pregnancy complications, a control placental clock (CPC) derived from uncomplicated pregnancies, and a refined RPC for uncomplicated term pregnancies. They also tested whether clocks trained on cord blood or other tissues could accurately estimate GA in placental tissue.
What was found
The robust placental clock predicted GA with a correlation of r > 0.95 and a median absolute error of less than one week in test data. Non-placental epigenetic clocks (such as cord blood clocks) failed to accurately estimate GA in placental samples. Specific quantitative performance figures for the CPC and refined RPC were not reported in the abstract.
Why it matters
Because pan-tissue and blood-based epigenetic clocks do not transfer well to placenta, these placental-specific clocks provide an accurate method for tracking fetal gestational age and studying developmental biology.
Limits
The abstract does not state the sample size, demographic profile, or clinical composition of the test dataset. Direct numeric accuracy metrics are omitted for two of the three models (CPC and refined RPC).
Cited by
- supports DNA methylation clocks developed for placental tissue can estimate the gestational age of a newborn.