Time-dependent changes in placental mRNA expression after delivery due to delayed specimen collection

Area of Science:

• Reproductive Biology
• Genomics
• Molecular Biology

Background:

• Current guidelines recommend placental specimen collection within two hours for gene expression analysis.
• Clinical settings present challenges for adhering to strict sample collection timelines.
• Delays in placental sample collection can impact gene expression analysis.

Purpose of the Study:

• To investigate temporal changes in placental gene expression over a 24-hour period post-delivery.
• To determine the stability of mRNA transcripts in placental tissue over time.
• To provide data to inform decisions regarding the inclusion of delayed placental samples in research.

Main Methods:

• Longitudinal sampling of eight placentas from uncomplicated pregnancies over 24 hours.
• Collection of chorionic villous tissue biopsies from three cotyledons at each time point to address heterogeneity.
• Quantification of 382 mRNA transcripts using NanoString nCounter and calculation of fold change relative to delivery.

Main Results:

• 84.3% of transcripts remained stable for at least 1 hour post-delivery.
• 80.2% of transcripts were stable for at least 2 hours post-delivery.
• 20.6% of transcripts maintained stability up to 24 hours post-delivery.

Conclusions:

• Placental gene expression exhibits temporal stability for a limited period post-delivery.
• Significant transcriptomic changes occur in placental tissue collected 24 hours post-delivery.
• A web application is available to help researchers assess the impact of delayed collection on their specific gene expression analyses.