At term, the ligaments of the pelvis change. This may result in which of the following to aid fetal passage?
1.A slight increase in the rotation of the femoral left
2.Transient degeneration of pelvic ground substance
3.Inferior placed angle to the iliosacral ligament
4.Mild enlargement of the pelvic cavity
5.Posterior rotation of the levator muscles allowing improved fetal passage
sol:
The change is one of relaxation of the ligaments, allowing more mobility at the sacroiliac and symphyseal joints and on occasion some instability. Whether or not these changes truly add to pelvic size has not been determined, but they seemto allow passage more easily, perhaps by accommodation.