Covid 19 and Pregnancy: Aspects Related to the Nutritional Level in Pregnant Women

Food, Nutrition and Diet Concepts

Food can be considered as the process by which the subject seeks in his environment, actively or passively, the food and nutritional chemical categories that he needs to satisfy the substantial energy requirements of his body [14].

Nutrition is a process of extraordinary biological complexity that refers to the distribution, use, transformation, storage and/or elimination of nutrients in the body. It involves the cellular metabolic function and is not likely to be changed by educational interventions on the individual.

In turn, the diet is nothing more than the set of chemical, food and nutritional categories, which can be ingested by the individual with the purpose of satisfying energetic and substantial needs. For a diet to be balanced or normal, it must meet four fundamental requirements:

It must be appropriate, that is, adjusted to the stage of life, sex and functional status of the subject. Be sufficient, which is to say provide the amounts of energy and nutrients that the cells of the different tissues and organs of the body may need.

• Varied: The diet must include food chemical categories that come from different sources (animal and vegetable) and of a different nature, assuring as a whole the energetic and substantial demands of the cells at the tissue and organic level.

• Balanced: This is the most difficult requirement to fulfill and means that each food and nutritional component must be present in the diet ingested in certain absolute and relative amounts, thereby avoiding stress on any metabolic pathway at the tissue-organic level.

• Food frequency: It is proposed that the amounts of food and nutrients to be ingested should be done with a certain frequency, each intake corresponding to a certain percentage of the person’s total energy needs.

Thus, it is proposed that a breakfast should be made, the most important of all, which provides 20% of the energy requirements; a morning snack (about 2 hours after breakfast), which provides 10% of the total energy required; lunch (2 or 3 hours later), which provides 30% of the total energy need; an afternoon snack (3 hours after lunch) that provides about 10% of energy requirements; lunch (about 2 hours after the afternoon snack), which provides about 20% of the individual’s total energy needs and, finally, dinner (about 2 or 3 hours after the meal), which provides about 10% of energy requirements.

Nutrition in Pregnancy

The Maternal-Infant Program in our country aims to detect all possible risk factors that may favor the birth of a low birth weight newborn, with maternal malnutrition being one of the aspects in which work must still be done to reduce infant morbidity and mortality. This is also associated with other factors such as early ages at which pregnancy occurs, the frequency of anemia, toxic habits and vaginal infection, among others [8].

The recommended mean weight gain for healthy primiparous women, who eat without restriction, should be 12.5-12.8 kg throughout pregnancy (5.15).

In our country, the validation of the weight at the beginning of pregnancy must be carried out before 13 weeks of gestation and, at present, the most precise indicator for nutritional evaluation, recommended throughout the world as a reference, is the calculation of the weight index. body mass (BMI=weight (kg)/height (m²)), proposing the following categories for this evaluation, according to Cuban tables used by the National Institute of Food Hygiene of high specificity and validated with the weight of the newborn: 16 Category BMI Total Minimum Gain recommended (kg) Low Weight ____=18.8 __14.2 Normal Weight____>18.8 to <25.6 __12.8 Overweight ____=25.6 to <28.6___7.0 Obese ____= 28.6 ____5.8 For women with a normal body mass index at uptake, a gain of approximately 0.4kg per week is recommended in the second and third trimesters of pregnancy, for low weight it should be 0.5kg per week and for overweight of 0.3kg per week.

Different studies demonstrate the important effect of low birth weight andprematurity on infant morbidity and mortality in developing countries [5, 6, 7], as well as its close relationship with poor nutrition in pregnant women.

• Proteins: They have a reparative function. In Cuba, the daily intake of protein for the pregnant and lactating mother should correspond to 12% of the recommended energy intake.

• Fats: Fats are of great importance due to their high energy density and participate in the synthesis of prostaglandins, prostacyclins among others. 15 to 30% of the recommended energy is required in the diet.

• Carbohydrates: Their main function is to provide energy. Their supply depends on the values ​set for the total energy intake of proteins and carbohydrates, ranging from 60% of the recommended total energy.5
• Vitamins and Minerals: Vitamins and minerals are essential compounds for the growth, development and maintenance of the human body, but they need to be acquired through food since it does not have the ability to synthesize them. Plasma concentrations of many vitamins and minerals decrease during pregnancy, possibly due to hemodilution; others are sensitive to heat, light, air and are eliminated through sweat. The most frequent deficits are of Vitamin A, iron phosphate. (5.14)
• Vitamin A: It is essential for normal vision, growth, differentiation of body tissues and the integrity of the immune system. Its deficit is associated with premature births, intrauterine growth retardation, as well as low birth weight. born.2,9 The daily requirements are: 6,000U/day. You can find the foods of animal origin (liver, fish liver oils, eggs and dairy products); certain deep yellow vegetables (carrots), deep green leaves (spinach and lettuce), and yellow fruits (fruit bomb and mango) Folic acid is vitally important for cell division and growth, so its deficiency is associated with low birth weight, premature placental abruption, and neural tube defects. Rich sources of this are liver, meat, eggs, legumes, whole grains, root vegetables (potato, pumpkin, sweet potato), vegetables (okra, watercress, turnip, peppers, tomatoes) and various fruits (melon, banana and citrus). It is almost completely destroyed during cooking. 200-300 mg/day are recommended during pregnancy and 100-200 mg/day during lactation.
• Iron: At present, there is sufficient evidence linking the iron deficiency anemia at the beginning of pregnancy with prematurity and low birth weight, the most frequent cause of neonatal morbidity and mortality [11, 12, 16].

Daily requirements are relatively low during pregnancy, around 1000 mg; however, only 0.8mg/day during the 1st. trimester and in the rest of pregnancy it can reach 6.3mg/ day.

The fundamental sources of heme iron (with absorption between 20-30%), is found in high concentration in the liver, blood products, beef, vegetables, poultry and seafood. Non-heme is found in cereals, legumes and vegetables, it is only absorbed in less than 5%. The intake of Vitamin C, beef, poultry and fish are capable of increasing this absorption, but only if they are found in the same food. (5.16) Iron deficiency is the most frequent and widespread nutritional deficiency in the world today. Just as it affects children and women in developing countries, it is the only deficient element that is significantly prevalent in developing countries industrialized [16, 19].

Iron Deficiency Anemia

It represents 95% of anemias in pregnant women. Pregnancy and childbirth represent a drain of 1-1.3 g of iron that is extracted, fundamentally, from maternal reserves. If the interval between pregnancies is short, and if there are predisposing factors (such as heavy menses, poor diet, intestinal parasitism, weight loss diets, intolerance to oral iron, and others), they will start this one with depleted iron stores. Iron deficiency anemia is characterized by a decrease in the erythrocyte mass, produced by the lack or decrease in the bioavailability of iron.

Pregnancy increases iron needs to about 1 mg. Approximately 500 mg are needed for increased globular mass. The fetus has received a total of 250-300 mg of iron as hemoglobin and hepatic deposits, with 20-100 mg of iron corresponding to fetal blood in the placenta. Iron demands as pregnancy progresses will depend, among other causes, on fetal growth, especially in the last trimester.

Iron requirements in normal pregnancy Total requirement: 1000 mg is actively transferred to the fetus and placenta 300 mg and eliminated through excretion routes 200 mg. The iron required by the increase in erythrocyte mass (450ml) [16, 20].

Some of the normal blood values ​in pregnancy are the following:

• Hemoglobin in the 1st. trimester: 120g/l and in the 3rd. quarter of 110g/l.
• Hematocrit of the 1st. trimester: 36-44% and in the 3rd. quarter of 33-42%.
• Serum iron 6.6-26 mmol/l.

For its prophylaxis, Prenatal is used: 1 daily tablet of 35 mg of elemental iron in the first trimester of pregnancy and 2 tablets during the rest of the pregnancy (from the 14th week of gestational age). The Institute of Nutrition and Food Hygiene (INHA) proposes for the pharmacological treatment of mild iron deficiency anemia, the oral dose of iron 60 mg daily elemental. If moderate or severe, the oral dose should be increased to 120 mg of elemental iron daily. In these cases, remember the daily administration of folic acid and Vitamin C. Doses greater than 120 mg of iron per day are not advisable because zinc and other nutrients compete with iron in the absorption process and a harmful imbalance can be created for the body. fetal development [16].