••• Chapter 3^ Physiology of Normal Pregnancy^29
❍ At what gestational age, does LDL and HDL cholesterol peak in pregnancy?
36 weeks and 30 weeks, respectively.
❍ Are pregnant women more likely to become ketonuric after starvation compared with nonpregnant
women?
Yes. Because there are higher concentrations of lipids and lower concentrations of glucose during fasting. The lipids
are preferentially metabolized to ketones. This is known as accelerated starvation.
❍ What is the effect of pregnancy on folate and B12 levels?
Both levels decrease (there is wide variation).
❍ What is the effect of pregnancy on erythropoetin levels?
There is a steady increase causing increased red cell mass. This is a paradoxical finding because erythropoetin is
stimulated by tissue hypoxemia, an unusual finding during normal pregnancy.
❍ What is the general effect of pregnancy on electrolyte concentrations?
Sodium, potassium, calcium, magnesium, and zinc are all mildly decreased by no greater than about 10% of
nonpregnant levels.
❍ What is the effect of pregnancy on copper concentrations in serum?
Increases from approximately 1.0 mg/L to 2.0 mg/L due to increased ceruloplasmin (copper-binding protein) levels
and fetal demand. Increased estrogen levels have been shown to increase copper and ceruloplasmin.
❍ How do the bicarbonate levels change during pregnancy?
They decrease by approximately 4 mEq/L to a level of 18 to 22 mEq/L.
❍ Why are bicarbonate levels decreased during pregnancy?
The developing fetus must offload its bicarbonate via the mother, inducing hyperventilation with resulting
respiratory alkalosis. Metabolic compensation by the kidney will restore normal pH balance by excreting
bicarbonate.
❍ Which two serum protein concentrations decrease during pregnancy and why?
(1) Total protein (70 g/L to 60 g/L—major decrease in the first trimester).
(2) Albumin (45 g/L to 35g/L—major decrease in the first trimester).
This is probably due to decreased protein synthesis in the first trimester, followed by dilutional factors during the
remaining two trimesters.
❍ What is the normal total body iron content in a non-pregnant woman?
2 g—about one half that of men.
❍ What is the total iron requirement from the beginning to the end of pregnancy?
Approximately 1 g.