Why is the occipital posterior position bad for natural labor?

Occipital posterior position is a misplaced fetus, which causes a lot of stress during normal labor, not only making labor longer, but also increasing the chance of maternal infection. And midwifery surgery is also used during labor, which can cause serious damage to the birth canal. If the delivery time is relatively long, the newborn may show scalp hematoma or edema phenomenon, and even intracranial hemorrhage may increase the probability of fetal death. In addition, it will increase the risk of postpartum hemorrhage, infection opportunities are many, long-term maternal failure to eat will also show electrolyte disorders.