What may lead to a decreased blood glucose level in a postpartum mother?

The delivery of the placenta can lead to a decreased blood glucose level in a postpartum mother due to the sudden drop in hormones that were produced during pregnancy, particularly insulin antagonists such as human placental lactogen (hPL) and estrogen. During pregnancy, these hormones can contribute to insulin resistance, which helps ensure that the developing fetus has adequate glucose supply. Once the placenta is delivered, these hormones are rapidly removed from circulation, leading to an increase in insulin sensitivity and a corresponding decrease in blood glucose levels.

Moreover, with the removal of the placenta, the body may experience a metabolic shift as it begins to adapt back to its non-pregnant state. This change can result in a temporary hypoglycemic effect, especially if the mother has been managing her diet closely and may not yet be replacing the energy consumed during labor and delivery.

In contrast, maternal exercise could potentially lower glucose levels, but it is generally not a primary factor postpartum. Administration of magnesium sulfate is primarily used for other medical conditions like eclampsia and can actually affect glucose metabolism. Increased food intake is more likely to raise blood glucose levels rather than decrease them.