Final answer:
During pregnancy, maternal adaptations include increased blood volume and cardiac output, increased respiratory rate, and typically a moderate rise in blood pressure. Endocrine changes feature a significant increase in hormone production with higher levels of thyrotropin, prolactin, and ACTH to support fetal development and prepare the mother's body for lactation.
Step-by-step explanation:
Maternal Adaptations and Endocrine Changes During Pregnancy
The maternal adaptations and endocrine changes during pregnancy are numerous and are crucial for the health of both the mother and the developing fetus. One key adaptation is the increase in blood volume and cardiac output, which rises by approximately 30 percent to accommodate the needs of the fetus and the changes in the mother's body. Additionally, the mother experiences an increased respiratory rate to meet the higher oxygen demands, with respiratory minute volume increasing by 50 percent.
Contrary to the decrease mentioned in the question, there's typically a moderate rise in blood pressure owing to the increased blood volume and the effects of pregnancy hormones. However, during the early stages of pregnancy, there can be a temporary decrease in blood pressure.
Regarding endocrine changes, there is an increase in hormone production rather than a decrease. The anterior pituitary gland enlarges and elevates the levels of thyrotropin, prolactin, and adrenocorticotropic hormone (ACTH). Thyrotropin and placental hormones elevate thyroid hormone production, consequently raising the maternal metabolic rate. Prolactin is key in the enlargement of the mammary glands in preparation for lactation, while ACTH boosts maternal cortisol secretion, aiding in fetal protein synthesis. Furthermore, estrogen and progesterone secreted from the corpus luteum and placenta are vital for maintaining the pregnancy and supporting the fetus and maternal tissues' growth.