Contractions are relatively weak, short, and distant in appearance at the beginning of labor. Labor for a first birth often lasts up to 24 hours with the most intense contractions occurring toward the end. Imminent birth is recognized with contractions occurring about 2-3 minutes apart and lasting up to a full minute. When the fetal head crowns at the vaginal opening, most women experience strong urges to push down and propel the fetus out of the birth canal. D. Delivery 1.
Delivery involves the actual birth or expulsion of the fetus from the uterus.
It often lasts 20-30 minutes. If the presentation is breech , the fetal buttocks or feet appear first in the birth canal. A transverse presentation is relatively rare where the fetal body or arm lies horizontal to the birth canal. As the fetal head is passed through the birth canal, the bones of the skull shift in conformance with the pressures exerted. The head at birth appears to be moulded or comes to a curved cone shape.