Why will an insulin-dependent diabetic have her insulin dose reduced following delivery?

The correct rationale for reducing the insulin dose in an insulin-dependent diabetic following delivery is that the anti-insulin effect ceases after placental separation. During pregnancy, the placenta produces hormones such as human placental lactogen, cortisol, and prolactin, which have anti-insulin effects. This results in insulin resistance, requiring the mother to increase her insulin doses to maintain glycemic control.

Once the placenta is delivered, these hormones dramatically decrease, leading to a reduction in insulin resistance. As a result, the body will become more sensitive to insulin, necessitating a decrease in the insulin dosage to avoid hypoglycemia.

Other options might touch upon different interactions that occur postpartum, such as metabolic changes or nutritional intake, but they do not directly address the fundamental physiological change related to the cessation of placental hormones and their effects on insulin sensitivity.