Caput succedaneumIt is the formation of swelling due to stagnation of fluids in the layers of scalp beneath the girdle of contact.
Girdle of contact may be bony or dilating cervix or vulval ring.
Swelling is diffuse baggy & not limited by the suture lines
mechanism-when head descend to press over the dilating cervix the overlying scalp is free of pressure but the tissue in contact with the full circumference of the girdle of contact is compressed.This interference with the venous return & lymphatic drainage from unsupported area of scalp leads to stagnation of fluid & appearance of swelling in the scalp .
It usually occurs after the rupture of membranes.
Importance=1>it signifies static position of head for a long period of time.
2>location of it gives idea about position of head occupied in the pelvis & the degree of flexion achieved.With increasing flexion caput is placed more posteriorly.