Pregnancy and Fat Metabolism

The pregnancy-related hormonal factors and changes in liver function lead to hyperlipidemia (increased concentration of cholesterol, triglycerides, and lipoproteins). All fat fractions in the mother’s organism increase at the beginning of pregnancy. There is an increase in serum lipids and serum cholesterol, which rises continuously within the 14th – 26th week and by the 36th week of pregnancy is about 50% higher than the initial values. The concentrations of total lipids, especially triglycerides and phospholipids, behave in the same way. An exception are the non-esterified fatty acids, whose concentrations only increase in the last trimester (third trimester) and are highest at birth. They are needed in particular for the rapid provision of energy during delivery for the pregnant woman. The increased fat load is less well tolerated during pregnancy. Attention should be paid to visible dietary fats and hidden fats – in convenience foods and fast foods – which account for about 50% of total fat intake in the typical diet. The guideline fat values are exceeded in many cases. For this reason, pregnant women should take care not to exceed a fat intake of 70 grams per day, or 30% of total energy intake. Excessive fat loads cause fat levels in the body to rise further, leading to ketosis. The risk for the occurrence of lipid peroxidation is also high. To prevent structural change of fats into harmful compounds, adequate antioxidant protection must be present. The need for the antioxidants such as vitamin E, C and beta-carotene is accordingly high.

Due to physiological hyperlipidemia, pregnant women should reduce dietary fats with a high content of saturated fatty acids and instead consume sufficient polyunsaturated essential fatty acids – omega-3 and -6 fatty acids, such as linolenic acid and linoleic acid. These are particularly important for the formation of cell membranes, blood lipids and prostaglandins. Prostaglandins are built up by specific enzymes from polyunsaturated C20 fatty acids, especially arachidonic acid, and are essential for pregnancy as well as birth. Prostaglandins control the contractions of the uterus (womb) and maintain its function. They also lead to important changes in the reactions of blood vessels as well as the coagulation system. Omega-3 fatty acids – found in flaxseeds, pumpkin seeds, fresh oily fish such as mackerel, herring and sardines – are needed by the fetus for healthy brain and eye development.

In addition to essential fatty acids, hyperlipidemia increases the need for vitamin C, B- vitamins, and calcium and magnesium.