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?

Serum creatinine and urea are waste products of protein metabolism that are normally filtered by the kidneys and excreted in urine.

In pregnancy, the glomerular filtration rate (GFR) increases by about 50%, which means more creatinine and urea are cleared from the blood.Therefore, serum creatinine and urea levels decrease in pregnancy compared to nonpregnant women.

A. Increased serum creatinine and urea levels are wrong because they indicate impaired kidney function or dehydration, which are not normal in pregnancy.

C. Unchanged serum creatinine and urea levels are wrong because they do not reflect the increased GFR in pregnancy.

D. Increased glomerular filtration rate is correct but it is not a finding regarding serum creatinine and urea levels, which are the focus of the question.

Normal ranges for serum creatinine and urea vary depending on the laboratory and the units used, but based on a nonpregnant reference interval of 45-90 μmol/l (0.51-1.02 mg/dl) for creatinine and 2.5-6.4 mmol/l (7-18 mg/dl) for urea, a serum creatinine of >77 μmol/l (0.87 mg/dl) and a blood urea of >8.5 mmol/l (24 mg/dl) should be considered outside the normal range for pregnancy.

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If progesterone were reduced or withdrawn, the uterus would contract more and peristalsis would increase, leading to possible preterm labor and digestive problems.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