A nurse is calculating the partial pressure of oxygen (PaO2) in the arterial blood of a pregnant client who is in her second trimester.

The nurse should use which of the following values as the normal range for PaO2 in pregnancy?

Leg cramps are painful muscle contractions that typically affect the calf, foot or both.

They are common during pregnancy, often happening at night during the second and third trimesters.

While the exact cause of leg cramps during pregnancy isn’t clear, various theories point to the following causes of leg cramps during pregnancy: 2

Pregnancy fatigue from carrying the extra baby weight

Compression of the blood vessels in the legs

Diet (an excess of phosphorus and a shortage of calcium or magnesium)

Pregnancy hormones since they seem to cause so many pregnancy aches and pains

Choice A is wrong because increased joint laxity is not a cause of leg cramps, but rather a result of hormonal changes that relax the ligaments and joints in preparation for childbirth.

Choice B is wrong because increased spinal curvature is not a cause of leg cramps, but rather a result of the changing center of gravity and posture during pregnancy.

Choice D is wrong because decreased muscle strength is not a cause of leg cramps, but rather a consequence of muscle fatigue and weight gain during pregnancy.

Normal ranges for calcium are 8.5 to 10.2 mg/dL, for magnesium are 1.7 to 2.2 mg/dL, and for phosphorus are 2.5 to 4.5 mg/dL.

Peristalsis and uterine contractility would increase.

This is because progesterone is a hormone that relaxes the smooth muscles of the uterus and the gastrointestinal tract during pregnancy.

If progesterone were reduced or withdrawn, the uterus would contract more and peristalsis would increase, leading to possible preterm labor and digestive problems.

Choice A is wrong because insulin resistance would be decreased, not increased, by lower progesterone levels.

Progesterone increases insulin resistance during pregnancy to ensure adequate glucose supply for the fetus.

Choice B is wrong because sweat and sebaceous glands would decrease production, not increase, by lower progesterone levels.

Progesterone stimulates the activity of these glands during pregnancy to regulate body temperature and protect the skin from infections.

Choice C is wrong because pyrosis (heartburn) would decrease in frequency, not increase, by lower progesterone levels.

Progesterone relaxes the lower esophageal sphincter during pregnancy, allowing gastric acid to reflux into the esophagus and cause pyrosis.