Decoding Human Placental Cellular and Molecular Responses to Obesity and Fetal Growth

Adv Sci (Weinh). 2026 Mar;13(17):e09691. doi: 10.1002/advs.202509691. Epub 2026 Jan 20.

Abstract

Maternal obesity increases the risks of large-for-gestational-age (LGA) births and subsequent cardiometabolic disorders in offspring. To identify placental signatures associated with these outcomes, we performed single-nucleus RNA sequencing on placentas from women with obesity delivering appropriate-for-gestational-age or LGA infants, compared to normal-weight controls. In maternal obesity, regardless of fetal growth, syncytiotrophoblasts showed upregulated hypoxia and TNF-α signaling, while cytotrophoblasts exhibited downregulated receptor tyrosine kinase signaling. However, villous non-trophoblasts displayed upregulated TNF-α signaling and inflammatory responses only in LGA placentas. Notably, Hofbauer cells in LGA placentas presented transcriptional alterations in immunometabolism-related genes and displayed elevated SPP1 expression, which potentially acts as a ligand for other placental cell types. We modeled key aspects of syncytiotrophoblast responses to adipose tissue using a customized microfluidic organoids-on-a-chip co-culture system. These findings revealed gene expression patterns of placental cells to maternal obesity that are shared or different between O-A and O-L, highlighting pathways for future mechanistic investigation.

Keywords: birth weight; maternal obesity; microfluidic co‐culture; placental transcriptomics; single‐nucleus RNA sequencing.

MeSH terms

  • Adult
  • Female
  • Fetal Development* / genetics
  • Fetal Development* / physiology
  • Humans
  • Obesity* / genetics
  • Obesity* / metabolism
  • Placenta* / metabolism
  • Pregnancy
  • Pregnancy in Obesity* / genetics
  • Pregnancy in Obesity* / metabolism
  • Signal Transduction
  • Trophoblasts / metabolism