Introduction

Despite the essential role of the umbilical arteries in the fetoplacental circulation, anatomical knowledge and potential functional implications of the anastomosis that these vessels perform is scarce.

Objective

To present an embryological, anatomical, and functional review of the umbilical arteries anastomosis (Hyrtl's anastomosis).

Materials and Methods

Search in Pubmed and Embase databases with indexed terms.

Results

The umbilical arteries, originating from the dorsal aortas in the embryo, establish their connection with the iliac artery between embryonic days 34-35. Their anastomosis is defined at the end of the first month. Methods for its investigation: dissection, injection-corrosion techniques, angiography, image analysis. By means of Doppler it can be clinically evaluated. Located 2-3 cm from the insertion of the cord to the chorionic plate, it can have several anatomical presentations that allow it to be classified according to the presence and orientation of the anastomotic vessel. After the anastomosis, the arteries enter the chorionic plaque as chorionic arteries, distributing themselves in patterns mediated by the type of insertion of the umbilical cord.

 Conclusions

The anastomosis allows an even distribution of blood in the placenta and contributes to the balance of pressures between the umbilical arteries when there is a discordance between their diameters.

Conflict of interest: None