A nurse is educating a pregnant client about the changes in her posture during pregnancy.

Which factor contributes to increased spinal curvature?

The correct answer is choice A. Increased joint laxity contributes to increased spinal curvature in pregnant women.

Joint laxity is caused by the hormone relaxin, which loosens the ligaments and joints of the pelvis and spine to prepare for childbirth.

This can result in increased lordosis (inward curvature) of the lumbar spine and increased kyphosis (outward curvature) of the thoracic spine.

Choice B is wrong because increased weight gain does not directly affect spinal curvature, but it can cause postural changes such as anterior pelvic tilt and forward trunk lean.

Choice C is wrong because increased muscle strain is a consequence, not a cause, of spinal curvature changes.

Muscle strain can occur due to the altered biomechanics and balance of the spine and pelvis during pregnancy.

Choice D is wrong because decreased muscle strength is also a consequence, not a cause, of spinal curvature changes.

Muscle strength can decrease due to reduced physical activity, hormonal changes, or pain during pregnancy.

Normal ranges for spinal curvature vary depending on age, sex, and measurement method, but generally they are:

Sacral inclination: 30-50 degrees

Lumbar curvature: 20-45 degrees

Thoracic curvature: 20-40 degrees

Cervical curvature: 20-35 degrees

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.