The effects of dietary cholesterol upon the hypercholesterolemia of pregnancy

The hypercholesterolemia which accompanies the normal human pregnancy is not known to be influenced by diet or other factors. The present experiment in fourteen pregnant women was designed to document this phenomenon under controlled metabolic conditions and to study the effect of dietary cholesterol upon this usual increase in serum cholesterol. The subjects included twelve normal subjects, one juvenile diabetic, and one type II familial hypercholesterolemic subject. They were fed controlled, nutritionally adequate diets which were equivalent except for the cholesterol content, which was cholesterol-free or 600-1000 mg from egg yolk daily. Calories were adjusted to permit weight gain of 1.4 kg per mo. The cholesterol-free diet lowered th mean serum cholesterol level in the 12 normal pregnant women from 234-187 mg/dl, a 20% decrease (-47 +/- 37 S.D.) (p less than 0.005). The addition of cholesterol to the diet invariably elevated the mean serum cholesterol concentrations to 223 mg/dl, a 19% increase (+36 +/- 12) (p less than 0.001). The mean serum triglyceride levels increased steadily throughout pregnancy regardless of diet, up to 198 +/- 43 (S.D.) mg/dl at term. Both serum cholesterol and triglyceride concentrations decreased strikingly 1 wk after parturition. These serum cholesterol and triglyceride responses occurred similarly in the familial hypercholesterolemic and the diabetic women. The increased serum cholesterol levels during the high cholesterol diets occurred largely in the low density lipoprotein (LDL) fraction. Despite the inevitable alterations of cholesterol and lipoprotein homeostasis which occur in pregnancy, the results of this study indicated that the usual hypercholesterolemia of pregnancy in women eating the general American diet was greatly ameliorated by a very low cholesterol, nutritionally adequate diet.