Gross and histological examination of Wharton’s Jelly in the equine umbilical cord.

This research article focuses on analyzing and describing the structure of Wharton’s Jelly (WJ), a substance within the umbilical cord, in horses through detailed microscopic and immunohistochemical studies. The study found that WJ was present in the amniotic section of umbilical cord and its weight did not vary between male and female foals, but more extensive research is needed to fully understand the changes in the umbilical cord throughout pregnancy and disease.

Objective of the Research

• The primary objective of the research was to microscopically and immunohistochemically describe the equine umbilical cord (UC) in normal pregnancies, with a specific focus on Wharton’s Jelly (WJ).
• Since earlier studies mostly focused on human UCs in both healthy and high-risk pregnancies, there was a knowledge gap regarding equine UC. This study aimed to bridge this gap.

Research Methodology

• The research team studied 47 healthy mares admitted to the hospital for delivery.
• Clinical data was collected regarding infant health and placental characteristics.
• UC samples were collected from three distinct locations: amniotic, allantoic, and the vein anastomosis region.
• The collected samples underwent histological analysis in which the thickness of different layers of arteries and veins and WJ in the different UC portions were measured.
• The weight of WJ was also measured and stained sections of the substance were examined using several techniques.

Findings of the Study

• According to the data collected from 19 colt and 28 filly foals, the weight of WJ was found to be consistent between the two sexes.
• WJ was present only in the amniotic section of the UC that is nearest to the foal’s abdomen.
• Sigificantly, the presence or the weight of WJ was not correlated with any measured clinical or UC parameters.
• Likewise, the tunica media, the middle layer of the arterial wall, was found to be thicker in the amniotic section of the UC, a trait also seen in human UCs in late pregnancy. This adaptation may function to resist compression from fetal movements and UC twisting.’

Conclusions and Future Directions

• This preliminary research describes both gross and histological structure of WJ in horses, a previously under-studied subject.
• However, the researchers believe that future studies are essential to further define changes in the UC through pregnancy and in disease conditions that affect either the mare or the foal.