Final answer:
Oxytocin is the medication given to induce labor as it stimulates uterine contractions, aiding in child delivery.
Step-by-step explanation:
The medication administered to a pregnant woman just prior to delivery to stimulate uterine contractions is Oxytocin. The primary hormone responsible for contractions during labor is indeed oxytocin, which becomes increasingly effective toward the end of pregnancy as the uterus develops more receptors for it. This hormone, produced in the hypothalamus and released from the pituitary gland, initiates a positive feedback loop where cervical stretching due to the fetal head pushing against the cervix causes the release of more oxytocin, resulting in increased intensity and frequency of contractions until the baby is born.