Endocrine Changes in Pregnancy

Pregnancy turns the placenta into a major endocrine organ. Its hormones support fetal growth, prepare the breasts for lactation, expand maternal blood volume, and progressively alter glucose and thyroid physiology. The same adaptations can make disease easy to miss. A low TSH may be a normal response to hCG, whereas vomiting with ketones may signal diabetic ketoacidosis even when the glucose is not markedly elevated. The experienced nurse asks two questions early: Is this expected for the gestational age? and Could this adaptation be exceeding the patient's ability to compensate? Endocrine priorities also change abruptly when the placenta is delivered. Placental hormones that drive insulin resistance disappear, while risks such as postpartum thyroiditis and Graves relapse emerge. Assessment, medication administration, and discharge teaching must therefore anticipate both the pregnancy state and the transition out of it.