Third trimester development of the feto-placental vasculature: A computational growth model.

BACKGROUND

Placental dysfunction is associated with adverse pregnancy outcomes, yet normal placental growth and vascular adaptation remain incompletely understood. Most available data pertain to term placentas, limiting insight into earlier stages of development. This study develops a mathematical framework that conceptualizes potential feto-placental vascular growth between 24 and 40 weeks of gestation in backward fashion. By working backwards from a term placenta, the model provides a systematic approach to simulating placental development and vascular remodeling, enabling hypotheses generation.

METHODS

A volume-filling algorithm was applied to generate three term placentas: two with central cord insertion (based on ex-vivo and in-vivo geometrical data) and one with marginal cord insertion (based on in-vivo geometrical data). A growth algorithm, incorporating literature-based scaling functions, was applied in reverse to downscale the term vasculature to 24 weeks. Growth was simulated using a reverse sigmoid function for lateral expansion and a linear scale factor for vertical growth, initiated at the cord insertion.

RESULTS

The model replicated vascular growth trends observed in literature, including a linear increase in umbilical artery diameter and linear vascular volume expansion. Placental topology was influenced by cord insertion, with central insertions producing symmetric growth, while marginal insertions exhibited uneven lateral expansion.

DISCUSSION: A mathematical framework that conceptualizes feto-placental vascular growth between 24 and 40 weeks of gestation is developed. The framework aligns with existing but scarce data in the literature. Based on these findings, further research directions in vascular versus tissue growth are proposed to deepen our understanding of placental growth, ultimately enhancing the provided model.