Which adverse effect is associated with high-dose oxytocin therapy?

• A. Water intoxication
• B. Hypertension
• C. Hypokalemia
• D. Anemia

Answer: (A)

High-dose oxytocin can act like vasopressin in the body, leading to antidiuretic effects in the kidneys. This causes water retention and, when combined with large volumes of IV fluids, can dilute the blood sodium level, producing water intoxication (dilutional hyponatremia). The resulting symptoms can include headache, confusion, nausea, vomiting, seizures, and even coma if severe. This risk underscores the importance of careful fluid management during active labor: use the smallest effective oxytocin dose, monitor intake and output, and avoid or limit hypotonic IV fluids. While oxytocin is essential for labor induction and augmentation, recognizing and preventing water intoxication helps keep both mother and baby safe.