What is one function of uterine contractions during labor?

Uterine contractions during labor play a crucial role in the process, and one primary function is to facilitate the dilation of the cervix. As contractions occur, they create pressure and pull on the cervix, causing it to thin out (effacement) and open (dilation) to allow the baby to pass through the birth canal. This is essential for cervical readiness before delivery, as a fully dilated cervix is necessary for the baby to be born.

While the expulsion of the placenta is also a function of uterine contractions, this occurs after the baby is delivered and is not related to the cervix's dilation during active labor. Similarly, the positioning of the infant can be influenced by contractions, but the primary purpose is to facilitate cervical changes necessary for delivery. Finally, signaling the end of labor is not a function of contractions themselves; rather, it is a result of the completion of the labor process. Hence, the dilation of the cervix stands out as a direct and essential function of contractions during labor.