Final answer:
A baby's birth is imminent when the "bloody show" occurs, which is the expulsion of the mucus plug from the cervical canal, generally happening 1-2 days before true labor begins. True labor involves regular, powerful contractions that intensify over time and a positive feedback loop with oxytocin release, aiding in childbirth.
Step-by-step explanation:
Several signs can suggest that a baby's birth is imminent, one of which is the "bloody show," an indication of labor's onset. This event involves the expulsion of a mucus plug that has accumulated in the cervical canal throughout pregnancy. The departure of this mucus plug is often accompanied by a small amount of blood and typically occurs 1-2 days before true labor begins.
True labor is characterized by regular contractions that become more frequent and powerful over time, and unlike practice contractions, or Braxton Hicks, they do not subside with hydration or rest. In the lead-up to labor, other physiological changes take place as a result of hormonal shifts. A significant drop in progesterone levels and the stretching forces exerted by the fetus increase uterine irritability, setting the stage for labor contractions that dilate the cervix and help to expel the newborn.
Additionally, a positive feedback loop involving the release of oxytocin aids in intensifying contractions. When the child pushes against the cervix, it stimulates the release of oxytocin, which in turn stimulates further contractions and facilitates the progression of the child through the birth canal.