What instrument is curved and designed to fit around the baby’s head during delivery?

The instrument that is curved and designed to fit around the baby’s head during delivery is forceps. Forceps are specifically designed to assist in the delivery process by providing a way to grasp the baby’s head, especially when the baby is in a position where additional help is needed to ensure a safe delivery. They can be used when labor is prolonged, or when there are concerns about the well-being of the baby or the mother.

Forceps are shaped to comfortably fit around the contours of the baby's head, allowing healthcare providers to gently pull the baby out during contractions. This procedure requires significant skill and care to ensure both the mother and baby's safety during delivery.

The other options do not serve this purpose. Scissors may be used in the delivery process, but they are typically for cutting the umbilical cord or other tissues, not for assisting in delivery. A scalpel is also not used for delivery; its primary function is for making incisions in surgical procedures. A cervical dilator is used to assist in preparing the cervix for labor but does not assist in the delivery process itself. Therefore, the role of forceps is specific and essential for assisting in the delivery of a baby when needed.