Week 28 to week 40 is grouped as third trimester, a final phase of pregnancy. A pregnant women faces problems like heartburn, frequent urination, body ache, swelling, sleeplessness, piles; while might develop gestational diabetes or blood pressure conditions. Healthy nutrition and routine may help ease out this physically and emotionally challenging trimester.
Healthy diet rich in fruits, vegetables, nuts, legumes, fiber, eggs, meat, and fish help provide the required essential supplement during this stage. It helps to maintain the pregnancy weight gain in the healthy range and produce the breast milk after birth. A pregnant woman needs approximately 450 extra calories daily during her third trimester. Drinking plenty of water during 3rd trimester ensures proper hydrations and helps reduce or prevents constipation. She should restrict excessive intake of salt and sugar. Avoid alcohol, smoking, caffenine, fried and spicy food, cold drinks, outdoor foods, raw meat and fish, unpasteurized milk or other dairy products.
Beside she should also continue with the prenatal vitamins and supplements prescribed by the doctor. Adequate calcium and vitamin D intake helps in growing fetus bones. Some other prenatal supplements include thiamine for healthy nervous system and cardiovascular system of baby; vitamin C, E which help prevent pre-eclampsia and folic acid. Folic acid is important in third trimester to ensure adequate fetal growth and prevent a low birth weight baby. During pregnancy vitamin supplementation should be under doctor's supervision.
Also refer. http://www.indiastudychannel.com/experts/42434-How-the-pregnancy-is-related-with-nutrition.aspx