Nutrition and multiple gestation.

Multiple pregnancy represents a state of magnified nutritional requirements, resulting in a greater nutrient drain on maternal resources and an accelerated depletion of nutritional reserves. The accelerated starvation which occurs in pregnancy is exaggerated with a multiple gestation, particularly during the second half of pregnancy, with more rapid depletion of glycogen stores and resultant metabolism of fat between meals and during an overnight fast. A reduced glucose stream from mother to fetus results in slower fetal growth, smaller birth size, as well as a higher risk of preterm labor and preterm birth. For this reason, diet therapy with a diabetic regimen of 20% of calories from protein, 40% of calories from carbohydrate, and 40% of calories from fat may be particularly useful. Iron-deficiency anemia has also been linked to preterm delivery and other adverse pregnancy outcomes. Mobilization of maternal iron stores, in addition to an adequate amount and pattern of gestational weight gain (including BMI-specific weight gain goals by 20 and 28 weeks gestation), has been associated with significantly better fetal growth and longer gestations in twin pregnancies. Supplementation with calcium, magnesium, and zinc, as well as multivitamins and essential fatty acids may also reduce pregnancy complications and improve postnatal health for infants born from a multiple gestation. Diet therapy for women pregnant with multiples is an important component of effective prenatal care.