Physiological changes of pregnancy include : a. Insulin levels increase b. Increased BMR c. Hypothyroidism d. GH decreases e. Blood volume decreases

**Core Concept**
During pregnancy, the body undergoes various physiological changes to accommodate the growing fetus, placenta, and increased maternal metabolic demands. These changes include alterations in glucose metabolism, thyroid function, and growth hormone regulation, ultimately leading to an increase in basal metabolic rate (BMR) and blood volume.

**Why the Correct Answer is Right**
Increased basal metabolic rate (BMR) is a hallmark of pregnancy, occurring due to the increased metabolic demands of the fetus, placenta, and maternal tissues. This rise in BMR is mediated by the increased levels of estrogen and progesterone, which stimulate the thyroid gland to produce more thyroxine (T4) and triiodothyronine (T3). Elevated levels of T3, in turn, increase the metabolic rate and energy expenditure in the mother. Additionally, the increased levels of progesterone also stimulate the growth hormone (GH) axis, leading to increased levels of insulin-like growth factor-1 (IGF-1), which further contributes to the increased BMR.

**Why Each Wrong Option is Incorrect**
**Option A:** Insulin levels do not increase in pregnancy; instead, insulin sensitivity decreases due to the increased levels of progesterone, leading to glucose intolerance and gestational diabetes mellitus (GDM).
**Option C:** Hypothyroidism is not a common finding in pregnancy; in fact, pregnancy is often associated with an increase in thyroid function, particularly in the first trimester.
**Option D:** Growth hormone (GH) levels actually increase in pregnancy, not decrease, due to the stimulatory effect of progesterone on the GH axis.
**Option E:** Blood volume increases in pregnancy, not decreases, by approximately 40-50% above non-pregnant levels, which is essential to meet the increased metabolic demands of the mother and fetus.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the increased metabolic rate in pregnancy is a physiological adaptation to meet the demands of the growing fetus and placenta. However, this increased metabolic rate also increases the risk of gestational diabetes mellitus (GDM) and other metabolic complications.

**Correct Answer:** B. Increased BMR