Oxytocin is regulated by a positive feedback mechanism, especially during childbirth. The hormone stimulates uterine contractions, which intensify until delivery, causing more oxytocin release and stronger contractions. This feedback loop continues until the baby is born, ensuring effective labor. In contrast, hormones like cortisol, insulin, and parathyroid hormone operate primarily via negative feedback to maintain homeostasis, not amplification of their own secretion.

Reference: Guyton and Hall Textbook of Medical Physiology, John E. Hall, 14th Edition.