Physiological Changes During Pregnancy
The correct answer is (c) increased conversion of glucose to glycogen, as pregnancy is characterized by an anabolic state in early pregnancy with enhanced insulin sensitivity and glycogen storage, though this question contains several physiologically inaccurate options.
Key Physiological Changes in Pregnancy
Hematologic Changes
- Hematocrit decreases during pregnancy, not increases, due to disproportionate plasma volume expansion compared to red blood cell mass, resulting in physiologic anemia of pregnancy 1
- This eliminates option (a) as incorrect
Respiratory Changes
- Pregnancy causes hyperventilation with hypocapnia (decreased CO2), not hypercapnia 1
- Progesterone stimulates the respiratory center, leading to increased minute ventilation and a compensated respiratory alkalosis with PaCO2 typically around 28-32 mmHg
- This eliminates option (b) as incorrect
Metabolic and Glucose Homeostasis
- Early pregnancy (first trimester) is characterized by an anabolic state with enhanced insulin sensitivity and increased conversion of glucose to glycogen for storage 1
- This represents the most physiologically accurate option (c) among the choices provided
- Later in pregnancy, there is a shift toward insulin resistance and catabolic metabolism to support fetal growth
Hormonal Changes
- Gonadotropin levels (particularly hCG) are markedly elevated during pregnancy, not reduced 1, 2
- Human chorionic gonadotropin (hCG) rises dramatically in early pregnancy and is commonly associated with nausea and vomiting of pregnancy 1
- This eliminates option (d) as incorrect
Cortisol and Corticosterone
- Cortisol and corticosterone production increases during pregnancy, not decreases 1
- There is increased production of both free and bound cortisol due to elevated cortisol-binding globulin
- This eliminates option (e) as incorrect
Clinical Context: Nausea and Vomiting in Pregnancy
Pathophysiology
- The patient's morning-predominant nausea and vomiting is consistent with nausea and vomiting of pregnancy (NVP), which affects 30-90% of pregnant women 1, 2
- NVP typically begins at 4-6 weeks gestation, peaks at 8-12 weeks, and subsides by week 20 1, 2
- Elevated hCG and estrogen levels, along with progesterone-mediated delayed gastric emptying, are implicated in the pathophysiology 1
Important Clinical Caveat
While this question asks about physiological changes, the most clinically relevant point is that early recognition and treatment of NVP may prevent progression to hyperemesis gravidarum, a severe condition requiring hospitalization 1, 2