Twins, Triplets Need More Food

POGS issues nutritional recommendations for multifetal pregnancies

Multifetal pregnancies are on the rise principally due to the growing rate of assisted forms of reproduction. Studies indicate that the incidence of twin births has grown from one in 56 births in 1980 to one in 34 in 1999, and that of triplets from one in 3,500 in 1973 to one in 541 in 1999. Among the triplets and higher order pregnancies, 20 percent were spontaneously conceived and 80 percent occurred as a result of assisted reproduction techniques.

    Because there are at least three individuals to feed and nourish adequately during multifetal pregnancy, utmost nutrition is needed for the mother and the fetuses in her womb. More than that, the incidence of prematurity and low birth weight is higher among infants born from multifetal pregnancies. This also leads to higher rates of perinatal mortality and morbidity.

    Which is why the committee on nutrition of the Philippine Obstetrical and Gynecological Society (POGS) has issued recommendations on maternal nutrition in multifetal gestation.

    Dr. Raul M. Quillamor, committee chair, discussed these recommendations during a symposium organized by POGS and Novartis Consumer Health Philippines.

    Noting that birth weight is correlated with the age of gestation at birth (the longer the age of gestation, the higher the birth weight), Dr. Quillamor stressed the need to modify maternal nutrition to increase the birth weight of infants. The optimal birth weights of babies born from multifetal pregnancies should fall within 3,000 to 3,500 grams for twins and 1,900 to 2,200 grams for triplets (Brown, 2000). But Dr. Quillamor said this is not the norm in the Philippines. Babies delivered from multifetal pregnancies are usually preterm and weigh low.

    Few studies have made a correlation between maternal weight gain and multifetal pregnancy outcomes. It has been observed that as with singleton pregnancy, maternal weight gain is positively and linearly related to birth weight in twin pregnancy. A 1973 study by Konwinski and colleagues demonstrated a strong relationship between the preterm delivery of twins and the rate of weight gain among women weighing less than 150 lbs. Moreover, low rates of weight gain in the first half of pregnancy (<0.85 lb./week) and in the second half (<1.3 lbs./week) have been associated with the birth of twins weighing less than 2,500 grams. The importance of weight gain in pregnancy was further emphasized by Pederson and colleagues in a 1989 study. They reported that women who continued to gain about one pound per week after 30 weeks were more likely to deliver twins with optimal birth weight (>2,500 grams) than women whose rate of gain declined late in pregnancy. In 1990, the Institute of Medicine of the National Academy of Sciences reported that weight gain of 1.5 lbs./week during the second and third trimesters may be appropriate for twin pregnancy.

    Although no data exist to support specific amounts for the first trimester, weight gains of four to six pounds may be beneficial.

    Two studies (Worthington-Roberts in 1998 and Luke, et al. in 1995) have examined weight gain and infant outcomes in higher-order multiple pregnancies. They showed that a 50-pound gain is appropriate and a weekly weight gain of 1.5 lbs. or more starting on the 23rd week of gestation results in better intrauterine growth.

Higher Dietary Requirements

    Ensuring adequate nutrition is the key component of care for women with multifetal pregnancy to avoid low birth weight.

    Energy. Several studies have established that women bearing twins have an increased need for energy and various nutrients because of higher weight gain and larger increase in tissue mass (bigger placenta, more fluid deposition, increase in tissue mass of the fetuses, and breast growth).

    Based on available research, it is not possible to recommend a level of positive energy balance for multifetal pregnancy. Said Dr. Quillamor: "We have no data to support any sound recommendation as far as the need for energy in multifetal pregnancies is concerned. For twin pregnancies, however, the adequacy of energy can be estimated based on weight gain."

    Theoretically, to gain 40 pounds, a woman with twins would need to consume approximately 35,000 Kcal more. This would amount to an average of 150 Kcal/day above the level for a singleton pregnancy. For a singleton pregnancy, there is an additional 300 Kcal per day on top of the total energy requirement (TER) of a non-pregnant woman. In multifetal pregnancy, there is a need for another 150 Kcal. This can be achieved through increased food intake and lesser physical activity.

    There are no studies so far to support recommended levels of protein, fat, carbohydrates, multivitamins, and minerals. Dr. Quillamor suggested taking a cue from the POGS Maternal Nutrition Guidelines for singleton pregnancy.

    Proteins. Since there is a greater mass of protein-containing tissue in multifetal gestation, it would be reasonable to conclude that the need for protein is higher than the 60 grams recommended for singleton pregnancies. The protein requirement of an individual is 1.7 g/kg body weight per day. Two more grams are needed during the first trimester, nine in the second, and 15 in the third. Han Wu's 1983 case study showed that giving 100 grams of protein and a 3,000 Kcal diet to a woman with quadruplet pregnanacy had no ill effects, and the diet seemed compatible with positive infant outcomes.

    Essential fatty acids. The need for linoleic and linolenic acids is higher in multifetal gestations as low levels could raise the risk of impaired development of the nervous and visual systems.

    Iron and other minerals. There is greater need for iron and other minerals due to an increase in red cell mass. However, the extent of requirement is not known.

    Dr. Quillamor said nutrition education, counseling, and other preventive services can improve the outcomes of multifetal pregnancies as may be gleaned from studies by Ellings, et al., Gardner, et al., and the Montreal Diet Dispensary. The Montreal study showed that adding 500 Kcal and 25 grams of protein to the diet of women at least 20 weeks pregnant yielded a weight gain of five pounds. This resulted in additional 80 grams of birth weight for the infant and lower LBW incidence.

    Dr. Quillamor noted that said while it was impossible to conclude that nutrition services were causally related to improved outcomes because of some limitations of the study, , the results provide evidence that nutrition intervention may substantially improve outcome.

Best Practice

    Based on available scientific data, Dr. Quillamor offered best practice recommendations for nutrition during multifetal pregnancy (Table 1):

•     40 to 45 pounds weight gain for twin pregnancy and 50 pounds in case of triplets.

•     For twin pregnancy , caloric intake 450 Kcal above the pre-pregnancy intake or the amount consistent with targeted weight gain progress. If the woman is not achieving the targeted weight gain, her dietary intake should increase. For triplets, caloric intake levels should promote targeted weight gain progress.

    While the specific level of nutrients needed by women with multifetal pregnancy has not been determined, it is suggested that the recommended dietary allowance (RDA) formulated by the Food and Nutrition Research Institute and Dietary Reference Intakes (DRIs) advisories be used as guide for dietary assessment and counseling. Nutrient intake for twin and triplet pregnancies should be within or a little above the DRI or RDA levels but it should be lower than the Tolerable Upper Intake Levels (ULs), stressed Dr. Quillamor.

    As for multivitamin and mineral supplementation, he advised practitioners to follow the recommendations of the Institute of Medicine of the National Academy of Sciences for multifetal pregnancy of more than 12 weeks AOG (Table 2).

    He warned against using recommendations obtained from websites, pamphlets, and consumer publications for lack of scientific data to support them. Instead, he referred physicians to the POGS Food Pyramid Guide for Pregnant Women, adding servings as may be necessary.

    He said that for multifetal pregnancies, two additional servings of breads, cereals, rice, and pasta are recommended; two to three more servings of vegetables and fruits; three more servings of milk, yogurt, and cheese, as well as meat, poultry, fish, dry beans, eggs, and nuts. For fats, oils, and sweets, Dr. Quillamor said additional three servings of foods rich in essential fatty acids may be given.