Lipid metabolism in pregnancy.

Serum cholesterol and triglyceride concentrations in 34 normal women were monitored before, during and after pregnancy. All women displayed an initial fall in both substances during the first trimester. The concentrations increased to maximum values during the third trimester. There was a considerable variation in the time required for this hyperlipidaemia to decline after delivery. Lactation appeared to be an important factor in this variation; women who bottle-fed their infants maintained an elevated serum triglyceride level for three times longer than those who breast-fed their infants.