A nurse is providing education to a pregnant client about the hormonal changes during pregnancy.

Which hormone is responsible for maintaining the corpus luteum and stimulating fetal growth ?

Back pain is a common symptom experienced due to increased muscle strain during pregnancy.

As the uterus grows and the center of gravity shifts, there is more pressure on the lower back muscles and ligaments.

This can cause pain, difficulty with balance, and reduced activity.

Choice A is wrong because leg cramps are not caused by muscle strain, but by other factors such as dehydration, electrolyte imbalance, or compression of blood vessels.

Choice C is wrong because pelvic pain is not a typical symptom of musculoskeletal changes during pregnancy.

Pelvic pain can be caused by other conditions such as urinary tract infection, preterm labor, or pelvic girdle pain.

Choice D is wrong because carpal tunnel syndrome is not a result of muscle strain, but of fluid retention and swelling that compresses the median nerve in the wrist.

This can cause numbness, tingling, or pain in the hand and fingers.

95 to 105 mmHg.

This is the normal range for PaO2 in pregnancy according to several sources.

PaO2 is the partial pressure of oxygen in arterial blood and reflects the oxygenation of the blood.

It is influenced by factors such as ventilation, perfusion, diffusion, and hemoglobin affinity.

Choice A is wrong because 27 to 32 mmHg is too low for PaO2 and would indicate severe hypoxemia or low oxygen levels in the blood.

Choice C is wrong because 500 to 700 mL is a measure of tidal volume, not PaO.

Tidal volume is the amount of air that moves in and out of the lungs with each breath.

Choice D is wrong because 7 to 10 L/min is a measure of oxygen flow rate, not PaO.

Oxygen flow rate is the amount of oxygen delivered to a patient through a device such as a nasal cannula or a mask.