Question

Explain the adjustments in maternal metabolism during pregnancy for the following macronutrients: carbohydrate, protein, and fat.

HOW and WHY do these changes occur and what effect do they have on the mother and the fetus?

Answer 1

Carbohydrate and lipid metabolism are in close relation with each other during pregnancy.Increased estrogen,progesterone and placental lactogen increase levels of triglycerides,lipid ,lipoprotein and apolipoproteins.Low density lipoprotein reaches its peak value by 36 gestational week but decreases before birth.The level of high density lipoprotein is the maximum at the 25th gestational week and has a tendency to decrease by insulin resistance to 32 week.High density lipoprotein stimulates the human placental lactogen through its receptors on the placenta.Lipids,lipoproteins and apolipoproteins decrease at various rates in the post partum period also by the contribution of lactation.Alterations in lipid metabolism causes accumulation of maternal fat stores in the early pregnancy inorder to enhance lipolysis in the late pregnancy.This provides glucose and amino acids for foetus while promoting usage of lipids as maternal energy source.

Protein metabolism:Foetus gets amino acids mostly from the mother through the placenta and the passage of amino acids is critical since amino acids are the structural components of the fetus.Maternal serum albumin decreases and globulin increases in pregnancy.Placental lactogen and human chorionic gonodotropin supresses deamination in the liver to prevent loss of amino acids to preserve amino acids for fetus.If mother gets insufficient carbohydrates and lipids,proteins are used as the energy source which is an desirable condition.