What is the main purpose of the modified Ritgen maneuver during delivery?

The primary purpose of the modified Ritgen maneuver during delivery is to prevent perineal lacerations. This maneuver involves applying pressure to the fetal vertex as the head emerges from the birth canal, while simultaneously supporting the perineum. By managing the rate and direction of the fetal head's movement, the maneuver helps to control the delivery of the head in such a way that minimizes trauma to the surrounding perineal tissues.

This technique is especially useful in reducing the likelihood of third- or fourth-degree lacerations, as the controlled delivery allows for better stretching of the perineal tissues. It also contributes to a smoother delivery process, reducing the speed at which the fetal head exits, which can further aid in preventing injuries.

The other options focus on different aspects of the labor and delivery process that are not the primary intent of the modified Ritgen maneuver. While proper fetal positioning is important, the maneuver specifically does not aim to rotate the fetus. Although it may incidentally speed up the delivery of the head by facilitating a controlled delivery, this is not its main purpose. Additionally, the maneuver does not assist with fetal monitoring, which involves separate techniques and equipment to assess fetal well-being during labor.