Variability of the trunks and divisions of the brachial plexus in human fetuses

The brachial plexus is an important part of peripheral nervous systems. The studies of variation of the brachial plexus and its parts in the prenatal period are extremely rare. The goal of the study was to assess brachial plexus trunk variability and their divisions in human fetuses. Examinations were carried out on a total of 220 brachial plexuses derived from 110 fetuses aged 4-7 months, including 50 females (45.45%) in a CRL range of 80-233 mm. The following methods were incorporated into the study: anthropological, dissection, digital image acquisition and statistical methods. Symmetry and sexual dimorphism was observed. Trunk variations were observed in 12 (5.45%) plexus divisions as well as in 74 (33.6%) variants cases. Variants were equally common in both genders and on both sides of the body. Variants of individual trunks were of a similar percentage, usually an observed central trunk formed by nerve roots C7 and C8. Anterior division of the middle trunk (ADMT) was the most variable division, observed in 63 (28.63%) cases. There was no asymmetry and sexual dimorphism. Trunk variants are rare and anomalies of divisions were observed in one-third of cases, regardless of the side of the body and sex. Brachial plexus variation recognition is important from a clinical point of view.