The recent intensive efforts for improving child survival status and global concerns for the child's health have drawn attention of researchers, national policy-makers and administrators to the impact of maternal nutritional status on fetal and neonatal health and outcome. The extremes of maternal nutritional status are likely to adversely affect the fetus. These may result in fetal maldevelopment, fetal death, untimely intrauterine growth retardation, etc.
PREPREGNANCY STATUS AND FETAL OUTCOME
The neonatal size is strongly related to maternal body mass index (BMI), weight, height and even maternal birth weight. The nutrition of female throughout her life (including fetal and childhood) as well as during pregnancy influences the growth of her fetus. Not only is mortality high among LBW babies, these small babies grow up to be small adult and, in the case of girls, small mothers who in turn give birth to LBW babies (Fig. 1.1). It has been observed that ‘maternal environment’ has a more powerful influence on fetal growth than genes. The birth weights of babies born after ovum donation are strongly related to the weight of the recipient mother, but not that of the donor mother.1 The ICMR multicentric study on high-risk urban slum and rural population showed a higher perinatal (50–60/1000 birth) and neonatal (35–61/1000 live births) mortality with maternal weight of 40 kg or less. The prevalence of coronary heart disease (CHD) was about 11 percent overall, and as in western studies, higher in those of lower birth weights. It is also higher in those where mothers were below average weight at antenatal booking. Lower birth weight is also associated with poorer adult lung functions.2
Maternal height, an indirect evidence of heredity, socioenvironment and nutritional status, has a determining influence on fetal and neonatal weight and mortality. As per ICMR multicentric study in India, the cut off height is 140 cm.
According to a study from Finland, mortality from CHD was more in men and women where mothers were short and had a high BMI.3 The prevalence of diabetes was also high in offspring of mothers with a higher body weight and larger external pelvic diameters. BMI is useful in predicting LBW and small or large for getational age infants. A low maternal weight is associated with LBW and overweight women deliver a greater proportion of large for gestational age infants.4,5
MATERIAL DIET AND FETAL OUTCOME
An expectant mother needs to be provided with adequate nutritional intake for maternal and fetal tissue growth and her own usual maintenance requirements. An acute (or) chronic deprivation of dietary intake may result in a poor pregnancy outcome. Reduced maternal intake of energy and protein during pregnancy results in restricted fetal (animal study) growth.6 According to Pune maternal nutritional study, although there were no association between neonatal size and the mother's energy and protein intakes, her intake of milk at 18 weeks and green leafy vegetable and fruits at 28 weeks were directly related to babies size.7 Women consuming green leafy vegetables (GLVs) every alternate day or more had babies almost 200 g heavier, than those who never ate them. There are some evidences that improving the micronutrient quality of mother's diets results in increased fetal growth. It has been observed that exposure to famines during late gestation, was associated with glucose intolerance, insulin resistance and increase in type 2 diabetes. Early gestational exposure was associated with higher LDL/HDL cholesterol concentrations and higher BMI and waist circumference. It is also observed that the balance of maternal protein and carbohydrate intake during pregnancy is related to blood pressure in the offspring.
The American national research council recommendations of daily dietary allowances for women before pregnancy and during pregnancy and lactation are as per Table 1.1.9
As per American Academy of Pediatrics and the American College of Obstetricians and Gynecologist, vitamins and mineral intake, more than twice the recommended daily dietary allowance, should be avoided during pregnancy.8
The complexity of the link between maternal and fetal nutrition probably explains why the impact of maternal diet on fetal growth remains far from clear.
NUTRITIONAL REQUIREMENTS DURING PREGNANCY
Traditionally pregnant and lactating women have been recognized as a vulnerable group from the health and nutritional point of view, requiring additional nutritional suport.17
Basal metabolic rate is reduced during the second and third trimester of pregnancy.18 Studies on work activity suggest that there is a reduction in the physical activity during pregnancy in majority of women from developed and developing countries.19 It is obviously an adaptive mechanism evolved to ensure that there is no deterioration in maternal nutritional status in women relying on habitual dietary intake.12
Extra calories are needed during pregnancy to build up her own tissue, to build fat stores, to make breast-milk and for growth of the fetus and placenta. Pregnancy requires an additional 80,000 kcal, which are accumulated primarily in the last 20 weeks. Caloric increase of, 300 kcal daily throughout the pregnancy is recommended by the National Research Council. Her gut absorbs nutrient better and her body uses them more efficiently than when she is not pregnant. Calories are necessary for energy and whenever caloric intake is inadequate, protein is metabolized for energy supply rather than being spared for its vital role in fetal growth and development.
Various Indian studies provide ample evidence that the women from upper income group who consume more calories per day have better pregnancy weight gain and mean birth weight as compared to lower income group.
Proteins are essential for fetal growth and metabolism as these provide essential amino acids and nitrogen. To the basic protein needs of the non-pregnant women are added the demands for growth and repair of the fetus, placenta, uterus and breasts and increase maternal blood volume. During the last 6 months of pregnancy about 1 kg of protein is deposited, amounting 5 to 6 gm/day. It is desirable that the manority of the protein be supplied from animal sources such as meat, milk, eggs, cheese, poultry and fish because they furnish amino acids in optimal combination. Milk and milk products are considered nearly ideal sources of nutrients, especially protein and calcium, for pregnant (or) lactating women.
Of the approximately 300 mg of iron transferred to the fetus and placenta and the 500 mg incorporated into the expanding maternal hemoglobin mass, nearly all is used after mid pregnancy. During that time, iron requirements imposed by pregnancy and maternal excretion total about 7 mg/day.
Scott and co-workers established that as little as 30 mg of elemental iron taken regularly once daily throughout the latter half of pregnancy provided sufficient iron to meet the requirements of pregnancy and to protect pre-existing iron stores.
The pregnant woman may benefit from 60 to 100 mg iron per day if she is large, has twin fetuses, is late in pregnancy, takes iron irregularly or has an anemia.
Because iron requirements are slight during the first four months of pregnancy, it is not necessary to provide supplemental iron during this time. Withholding iron supplementation during the first trimester of pregnancy avoids the risk of aggravating nausea and vomitting.
Severe anemia is associated with higher hemoglobin percent and ferritin values in the fetus and a significant decrease in birth weight and gestational age.13
If folic acid is administered in the periconceptional period, i.e. before and during early pregnancy then it is known to prevent the neural tube defects. Since 1992, the public health services have recommended that all woman capable of becoming pregnant should consume 0.4 mg of folic acid daily throughout their childbearing age.
Severe maternal folate deficiency leading to megaloblastic anemia has been associated with fetal growth retardation. During pregnancy and lactation 0.8 mg/day is considered appropriate.
The pregnant woman retain about 30 mg of calcium, most of which is deposited in the fetus late in pregnancy. This amount of calcium represent only about 2.5 percent of total maternal calcium, most of which is in bone, and which can readily be mobilized for fetal growth.
Heaney and Skillman (1971) demonstrated increased calcium absorption by the intestine and progressive retention throughout pregnancy. Recent studies have demonstrated a possible role of calcium supplementation to prevent hypertensive disorder of pregnancy.
Severe zinc deficiency may lead to poor appetite, sub-optimal growth and impaired wound healing. Profound zinc deficiency may cause dwarfism and hypogonadism. It may also lead to specific skin disorder acrodermatitis enteropathica.
In a randomized study of 580 women, infant born to zinc supplemented woman were slightly larger (mean 125 g) and had a slightly larger head circumference.
The effect of deficiency and excess of other minerals are included in Table 1.2 and that of vitamins in Table 1.3.
EFFECT OF FOOD SUPPLEMENTATION DURING PREGNANCY
The effect of food supplementation to under nourished women on course and outcome of pregnancy were under taken in the National Institute of Nutrition, Hyderabad,14 India which showed that food supplements during pregnancy resulted in improvements in birth weight and reduction in prematurity rate. Studies from Guatemala,15 showed that calories were the critical components of dietary supplements in relation to improvement in birth weight.
One of the major problems in food supplementation programs is that even when the logistics for reaching the food of women have been meticulously worked out and efficiently carried out food sharing within the family of the recipient results in the ‘target women’ not getting the supplement in significant quantities.
RECOMMENDATIONS FOR WEIGHT GAIN IN PREGNANCY
By the 1970s, women were encouraged to gain at least 11.4 kg (25 Lb) to prevent preterm births and fetal growth restriction. In 1997, the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists recommended a weight gain of 11.5 to 16 kg (25–35 Lb) for women with normal pre-pregnancy body mass index. Normal physiological events cumulatively account for about 9 kg as fetus, placenta, amniotic fluid, uterine and breast hypertrophy, increased blood volume and retained extracellular and extravascular fluid. The remainder of the weight gain appears to be mostly maternal storage fat.16 Low maternal weight gain, BMI or skin folds in pregnancy are associated with higher offspring blood pressure and insulin resistance. Parker and Abrams,25 showed that excessive weight gains were linked to large for gestational age infants and correspondingly increased cesarean delivery.17
EFFECTS OF VEGETARIAN DIET
Even with low cost balanced diets, which lower income groups can afford and which are composed entirely of vegetable foods and milk, can adequately meet the essential nutrient requirements.
As per American Dietetic Association “well planned vegetarian diets are consistent with good nutritional status”.18
Cereals and millets are rich sources of complex carbohydrates and along with pulses and vegetables they also provide dietary fiber. Cereals, nuts, vegetable fat (oils) and tubers are good source of energy. That vegetarian diets can provide the energy needs of body is hardly disputed.
The fatty acid composition of vegetable oils may be considered wholesome and indeed nutritionally superior to that of animal fats. Vegetarian diets can thus fully meet the nutritional needs with respect to fats and essential fatty acid requirement even more satisfactorily than animal fats.
Cereals are generally poor in the essential amino acid lysine and this lysine deficiency can be easily offset by the inclusion of pulses and legumes which are rich in lysine.
Vegetables, especially green leafy vegetables and fruits are rich sources of carotenoides (Specially B-carotene, which are precursors of vitamin A), vitamin C, iron and calcium. With a judicious combination of cereals, pulses, vegetables, fruit and milk, it should be possible to ensure a diet of good nutritive value, which would fully meet all essential nutrient requirements.
Iron Deficiency in Vegetarian Diets
The risk of iron deficiency is greater with purely vegetarian diets as compared to nonvegetarian diets. Heme iron from cellular animal tissue is highly bioavailable. Vegetarians however rely on non-heme iron, which is relatively less well-absorbed than heme iron.
Vitamin C enhances the iron absorption whereas phytates and phosphates, inhibits the iron absorption. Therefore it is important that vegetarian dietaries include foods rich in ascorbic acid, which enhances the bioavailability of iron.
IS NONVEGETARIAN DIET ESSENTIAL?
In fact there is nothing in modern nutrition science to suggest that meat intake is obligatory in order to ensure optimal nutrition.19 All this proves that vegetarian diet is adequate to fulfill the nutrition requirements of pregnant and lactating mothers.
LACTATION AND MATERNAL NUTRITION
Recent recommendations for the exclusive breastfeeding are till the age of 6 months. This has been necessitated by evidence of improved infant survival with early and sustained exclusive breastfeeding for the first 6 months of life.20
Breast milk is influenced by maternal nutritional intake of lipids, selenium, iodine and certain vitamins. The composition is also influenced by the infant's weight and gestation as each mother produces breast milk most suitable for her infant's requirement. Even chronically malnourished women are capable of producing adequate milk for their infants.18
Barker's (FOAD) Hypothesis
Initially studies were carried out in UK on 1586 men in Sheffield5 and on 5654 men in Hertfordsihire.6 Later studies were carried out in two Indian hospitals one in Pune and another in Mysore related to fetal origin of adulthood diseases (FOAD). According to him the roots of coronary vascular disease (CVD) lay in the effect of poverty on the mother resulting in under nutrition in fetal life and early infancy.
The salient features of hypothesis are summarized in Table. 1.4
Anemia in Pregnancy
Anemia is the most important and most common of all micronutrient deficiencies in pregnancy. Low dietary intake of iron and folate and poor bioavailability of iron from Indian diets were identified as factors responsible for iron and folate deficiency and consequent anemia. In India, anemia antedates pregnancy get aggravated due to the increased and unmet demands of pregnancy, blood loss during labor and advent of successive pregnancies perpetuate it.21
The national anemia prophylaxis program of iron and folic acid distribution to pregnant women was initiated, to reduce the prevalence of anemia. Anemia still remains the major nutritional problem associated with maternal and peri-natal morbidity and mortality. Efforts to reduce the prevalence and severity of anemia prior to pregnancy should also be taken up as a long-term measure.
Dietary Intake, Physical Work and Nutritional Status
Various studies have shown that a combination of reduction in dietary intake to below habitual levels and simultaneous increase in physical activity causes a “break down” of normal adaptive processes and results in deterioration of maternal nutritional status and poor intrauterine growth of the fetus.21 Poor dietary intake during the pregnancy, hard physical work and anemia, result in poor weight gain during pregnancy. Inadequate weight gain results in LBW babies. According to study, conducted by Agarwal et al, the women who were undernourished, underfed and were doing heavy physical work for domestic duties, during pregnancy which negatively influenced infant weight and length at brith.22 However, pregnant resident doctors doing active duty didn't show any adverse effect on birth weight.23 Conversely Hatch (1993) in American women on low-moderate and heavy exercise found increase in birth weight by 100 grams and 300 grams respectively.24 Rabin (1990) also reported marginal increase in birth weight in British women doing full time employment and those having longer hours of sleep.25 Maternal under nutrition has been associated with placental changes suggestive of hypoxia; resulting in reduced placento-fetal circulation, these changes possibly get aggravated due to hard physical activity. In contrast, well-nourished pregnant women undertaking regular exercises improve placento-fetal circulation.
In circumstances where women have to continue to do heavy work throughout pregnancy, steps to ensure adequate dietary intake may reduce though not completely eliminate the adverse consequences of heavy work on maternal nutrition and the course and outcome of pregnancy. The crucial factor that determines the maternal nutritional status and outcome of pregnancy might be neither the dietary intake nor the physical work done during pregnancy, but the energy intake and energy expenditure. The calorie gap could be diminished either by attempting to reduce the energy expenditure or by increasing dietary intake.
Health education to well-nourished women not to overeat during pregnancy and lactation may become an important interventional strategy to reduce obesity and its adverse consequences in later life. Nutrition and Health Consequences of Adolescent Pregnancies.
Various studies indicate that pregnancy in he early teens before the girl in 16 years is associated with adverse effect on maternal nutrition, birth weight and survival of the offspring. The extranutritional requirements for adolescent growth spurt might be the major factor responsible for the observed poor nutritional status of girls who conceived before 16 years of age.21
Lower maternal body weight, lower pregnancy weight gain, higher prevalence of anemia and possibility of pregnancy induced hypertension might account for the observed lower mean birth weight and higher preinatal and neonatal mortality rate in these groups, both in urban and rural areas.26
There is an imminent need to increase community awareness regarding adverse consequences of early teenage conception and mobilize social support for strict implementation of laws regarding age at marriage.
Lactation and Second Pregnancy
Obviously the dual stress of pregnancy and lactation may be expected to widen the already yawning gap between actual dietary intakes and nutrient requirement investigations undertaken by the national institute of nutrition, Hyderabad, indicate that irrespective of the duration of lactation women who conceived during lactation weighed less in all the trimesters of pregnancy than those who conceived after lactation. The difference in body weight was more marked in the third trimester especially in women who conceived during the first six months of lactation. The reasons for this are as follows:
- They did not have enough time to recover from the stress of the previous pregnancy;
- The volume of milk secretion and nutrient loss in milk were greater in the 1st year of lactation; and
- A substantial number of these women were working outside home and, therefore, had to face energy needs for work outside the house.
Nutritional Status and Reproductive Performance of Working Women
Studies indicate that gainful employment of urban women outside the house in jobs requiring only moderate physical activity is associated with
- Improved financial status in urban high and middle-income groups;
- Improved maternal nutritional status in the lower middle income group; and
- Prevention of deterioration of nutritional status due to poverty in the urban low-income group.26
Available data shows that rural and urban poor women engaged in manual labor are undernourished and overworked. It is not possible for them to refrain from seeking gainful employment because, if they do so, their families would have a still lower economic status and purchasing power. There is an urgent need to evolve and utilize innovative, inexpensive technologies to reduce the burden of work in such women.
In view of the known vulnerability of the pregnant women and young children to a variety of physical and chemical insults, it is important to see that they do not enter those occupations, where there is a risk of exposure to hazardous agents.
Nutrition and HIV Interactions
In the nineties, HIV infection has emerged as a major cause of severe forms of under nutrition both in men and women belonging to reproductive age group and in children.
India has the unique distinction of being the first country in the world that initiated a nation wide sero-surveillance for HIV infection and started a well-defined national AIDS control program early in the HIV epidemic before many AIDS cases were reported in the country.
MISCONCEPTION ABOUT NUTRITION DURING PREGNANCY/LACTATION
There are various misconceptions, beliefs and tabors regarding the nutritional diet of pregnant and lactating mother in the developing countries like India due to the blind faith in the age-old rituals. Several foods are considered bad. Most of the women have apprehension that if they it more, baby will be large resulting in difficult delivery.27 The list of food items which are avoided along with its suspected effects on pregnancy and lactation are as follows:
- Rice: Obesity and stitch infection
- Brinjal, ground nut: Allergic rash
- Spicy food: Loose stools in baby
- Curd: Cough
- Cold water/more water: Distension of abdomen
- Bengal gram (Channa dal): Indigestion
- Fried food only: Jaundice in baby
- Banana: Cough in baby
STRATEGIES AND INTERVENTIONS FOR IMPROVING MATERNAL NUTRITION
The available data of the 1980s shows that in the last two decades there had not been any substantial reduction in either the magnitude or severity of maternal under nutrition and anemia. In the 1990s, the primary health care infrastructure was available for screening of pregnant women for these problems. Hence, the alternative strategy of screening all pregnant women, tailoring the intervention according to their needs and monitoring them is possible through the existent infrastructure.13
In the middle and upper income group, overeating, obesity and disorders associated with it are increasing. Women, eating more during pregnancy and lactation is often the beginning of the vicious cycle of creeping increase in weight. What is also a matter of concern is the tendency among women to retain the weight they have gained during pregnancy. After pregnancy, women have surplus weight mainly because of lack of activity”. This weight of surplus weight re-emphasizes the golden rule of lifestyle modification.
Fertility regulation using proven, effective and safe contraceptives may in fact be the most important tool for developing countries to escape from poverty and the most important non-nutritional intervention to improve health and nutritional status of not only women and children but also the entire family.
Majority of world's population experiences suboptimal fetal growth. Rates of IUGR are highest in developing countries, the South Asia being one of the worst affected regions. The economic growth is predisposing to childhood and adult obesity, especially in cities of these countries.28 According to Barker's hypothesis, increasing child and adult obesity along with persistently poor fetal growth creates a high risk of adulthood diseases. There is possibility of epidemic outbreak of these problems. It suggests that, several common degenerative disorders could be prevented, by improving maternal health and fetal development. This may be attainable by persuading men and women in middle age to return to primitive” lifestyles, and more positive than concluding that large number of people have genes that are incompatible with modern living.29 The optimal range of maternal body mass index, and the relative disadvantages of excessive thinness and excessive adiposity, are, however, still unknown. We must make all efforts to improve the diets of pregnant and lactating mothers in order to sustain their health and nutrition. Dietary supplementation of undernourished mother may have the effect of simply making them more adipose, which may have disadvantages for fetus.
- Brooks AA, Johnson MR, Steer PJ, Pawson ME, Abdalla HI. Birth weight: Nature or nurture? Early Human Dev 1995;42:29–35.
- Stein CE, Kumaran K, Fall CHD, Shaheen S, Osmond C. Relation of fetal growth to adult lung functions in South India. Thorax 1997;52:895–899.
- Forsen T, Erriksson JG, Tuomilehto J, Teramo K, Osmond C, Barker DJP. Mother's weight in pregnancy and CHD in a cohort of Finnish men: Follow-up study. Br Med J 1997;315:837–840.
- Kramer S. Determinants of low birth weight. Methodological assessment and meta-analysis. Bull WHO 1987;65:663–737.
- Gopalan C. Low brithweight. In: Nutrition Research in South East Asia. WHO/SEARO New Delhi, 1994:13–31.
- Harding JE. The nutritional basis of the fetal origins of adult disease. Int J Epidemiol 2001;30:15–25.
- Rao S, Yajnik CS, Kanade A, Fall CHD, Margetts BM, Jackson AA. Intake of Micronutrients-rich foods in rural Indian mother's is associated with the size of their babies at birth; the Pune maternal nutrition study. J Nutr 2001;31:1217–1224.
- Cunningham FG, Gant NF, Leveno KJ, Gilstrap LC, Hauth JC, Wenstrom KD. Prenatal Care (Nutrition). In: Williams Obstetrics, 21st edn. McGraw-Hill New York: 2001:221–247.
- FAO/WHO/UNU. Energy and Protein Requirements. WHO technical report series 724. WHO Geneva: 1985.
- Durnin JVGA, Food consumption and energy balance during pregnancy and lactation. In Abei H, Whitehead RG, Huber BH (eds): Maternal nutrition in pregnancy and lactation. New Guinea 1980:86–95.
- Durnin JVGA. Energy requirements in pregnancy: An integration of longitudinal data from the five countries study. Lancet 1987;2:1131–1133.
- Ramachandran P. Nutrition and influence on the mother/child. Dyad. ACC/SCN Symposium Report. United Nations New York: 1992:47–53.
- Venkatachalam PS. Maternal nutritional status and its effect on the newborn. Bull WHO 1982;26:193–201.
- Lechtig AJ, Habicht JP, Delgado H, et al. Effect of food supplementation during pregnancy on birth weight. Pediatrics 1975;56:508–528.
- Hytten FE. Weight gain in pregnancy. In Hytten FE, Chamberlain G (eds): Clinical Physiology in Obstetrics, 2nd edn. Blackwell, Oxford: 1991:173–85.
- Parker JD, Abram B. Prenatal weight gain advice: An examination of the recent prenatal weight gain recommendations of the Institute of Medicine. Obstet Gynecol 1992;79:664–675.
- American dietetic association position paper: Position paper on the vegetarian approach to eating. J Am Diet Assoc 1980;77:61–69.
- Gopalan S, Puri RK, Sachdev HPS. Adequacy of vegetarian diets for optimal nutrition of mother and child. In Sachdev HPS, Choudhary P (eds): Nutrition in children: Developing country concerns. BI New Delhi: 1994:143–155.
- Huffman SL. Maternal malnutrition and breastfeeding: Is there really a choice for policy makers? J Trop Pediatr 1991;37:19–22.
- Ramachandran P. Strategies and Interventions for improving maternal nutrition. In Schadev HPS, Choudhary P (eds): Nutrition in Children. Developing Country Concerns. BI New Delhi: 1994:470–480.
- Agarwal S, Agarwal A, Agarwal KN, Agarwal DK, Bansal A. Physical activity and pregnancy outcome in rural undernourished women. Indian Pediatr 2001;38:1017–1022.
- Klebanoff MA, Shiono PH, Rhoads GG. Outcome of pregnant in a national sample of resident physicians. N Engl J Med 1990;323:1040–1045.
- Hatch M, Shy X, Mclean DE, Levin B, Begg M, Reuss L. Maternal exercise during pregnancy, physical fitness and fetal growth. Am J Epidemiol 1993;137:1105–1114.
- Rabin CS, Anderson HR, Bland JM, Brooke OG, Chamerlain G, Peacock JL. Maternal activity and birth weight : A prospective population based study. Am J Epidemiol 1990;131:522–531.
- Ramachandran P. Nutrition in pregnancy. In Gopalan C, Kaur S (eds): Women and nutrition in India. Nutrition foundation of India New Delhi: 1989:153–193.
- Ghosh S. Maternal health and nutritional. In: Nutrition and child care: A practical guide. Jaypee New Delhi: 1997:25–42.
- Asia Development Bank and International Food Policy Research Institute. Malnutrition in the Asia and Pacific. In Gillespie S, Haddad L (eds): Attacking the double burden of malnutrition in asia and the pacific. International food policy research institute Manila: Asian development bank/Washington: 2001.
- Fall CHD. The fetal and early life origins of adult disease. Indian Pediatr 2003;40:480–502.