Nutrition in Pregnancy

Human nutrition affects practically every process and function in the body, from health and immunity, through the aging and reproduction processes, to mental health and cognitive abilities. For pregnant women, nutrition is even more critical, because along with the health and well-being of the mother, it shapes the development and future of the child.

The topic of nutrition during pregnancy has become even more meaningful to me over the past few months, as my wife and I are expecting our second child—and a person can never know everything. Additionally, the wonderful doctors from the Holistik clinic invited me to hold a series of lectures on this subject. The feedback from future mothers was beautiful, so I decided to share the content of those lectures here in the form of a blog post.

Why it matters what you eat during pregnancy

To build a house, we need many things. Since we are starting from scratch, we need sand, mortar, bricks, windows, roof tiles… We can either buy these construction materials or salvage them from an old house to use for the new one. It is quite similar when making a new human being.

During pregnancy, a new human being must develop from a single cell. This means that all organs, including bones, skin, and the brain, need to be formed, which requires a lot of materials. Just like in the house example, these building blocks can come from two sources. New components can only be obtained from food, while anything missing must be pulled from reserves—meaning from the mother, since the baby does not have its own depots yet. However, if intake is insufficient and the mother's reserves become depleted, it can lead to a series of consequences for both maternal and child health. Furthermore, even after a successful delivery and the birth of a healthy baby, the aftermath of drained reserves can prolong the mother's recovery time and increase the chances of complications.

One rarely mentioned aspect of nutrition during pregnancy is prenatal habit formation, which is the development of food preferences in the baby before birth. Specifically, even before birth, the baby receives substances from food through the umbilical cord, building a preference or an aversion toward the types of food consumed. These earliest habits can have a lifelong effect, both regarding preferences in food choices and metabolic processes, such as the secretion of appropriate digestive enzymes.

How nutritional needs change

During pregnancy, the demand for most nutrients increases, as does the need for total energy. However, this increase is very uneven for different nutrients and different stages of pregnancy. For instance, the need for some substances rises by 50 to 100%, while for others there is no change at all. Also, the increase in requirements during the first trimester for most nutrients is relatively small and unnoticeable, whereas in the second and third trimesters, it becomes much larger and more significant.

Interestingly, even though the demand for certain nutrients jumps drastically, the mother's body adapts to this by increasing the efficiency of nutrient absorption from food. Because of this, while needs do increase, a massive surge in actual food intake is not strictly necessary, and good habits before pregnancy remain good habits during pregnancy.

Energy

Throughout pregnancy, total energy demands understandably rise. This energy is essential to make up for the increased expenditure needed to develop new tissue and build up energy reserves for both the mother and the fetus. The exact amount of energy in calories varies across different sources. A general rule of thumb is that during the first trimester, there is almost no increase in energy needs, or they are very small, around 50 to 100 kcal per day. During the second and third trimesters, requirements increase more noticeably, but at the same time, a reduction in the mother's physical activity occurs, which saves energy.

According to some sources, during the second and third trimesters, women need about 340 to 450 additional calories per day. According to others, the requirement in the second trimester grows by about 350 kcal, and in the third by about 500 kcal per day. However, this estimate assumes that the mother had a normal and healthy weight before pregnancy. For women who entered pregnancy with excess weight, the additional energy requirements decrease inversely. On the other hand, for women who entered pregnancy with insufficient energy reserves, the need for extra energy goes up.

Carbohydrates

An increased intake of sugars during pregnancy is necessary for the baby's growth and development, but also for the mother's health. Glucose is used as the primary source of energy during fetal growth. However, a massive spike in the mother's blood glucose levels is linked to alterations in prenatal baby growth, resulting in accelerated growth of the baby's mass in late pregnancy. This leads to an increase in the baby's length and weight at birth, which is why significantly elevated glucose levels are strongly connected with increased risks of unfavorable outcomes for both child and mother.

Blood glucose levels can be stabilized by making good food choices—specifically, avoiding frequent consumption of foods with a high glycemic index, such as breads and pastries, potatoes, rice, sweetened beverages, sweets, watermelon, and the like.

Proteins

During pregnancy, there is a rapid surge in blood volume and the building of new tissues, for which larger quantities of protein are indispensable. Additionally, the growth of the fetus and placenta are highly protein-demanding processes, making the need for additional protein intake during pregnancy fully expected.

Daily protein needs are measured per kilogram of body weight. The current recommendation for the general population is between 0.88 and 1.1 grams of protein per kilogram daily. For pregnant women, daily requirements rise to 1.2 g/kg in early pregnancy (up to week 16) and 1.52 g/kg in late pregnancy. But what does this mean in practice?

Good protein sources include meat, fish, eggs, dairy products, nuts, soy products, and certain vegetables. To meet daily protein needs, it is enough to have 2 to 4 servings of protein-rich foods throughout the day. Here is a brief overview of the most significant protein sources with protein amounts per 100g of the food item:

• Meat and fish: around 25 grams of protein

• Nuts: around 20 grams of protein

• Milk, yogurt, and similar: around 5 grams of protein

• Cheeses: vary from 20 to 30 grams of protein

• Tofu: around 8 grams of protein

• Legumes (beans, peas, lentils...): vary drastically depending on the type, but contain between 7 and 20 grams of protein

Fats

Fats are necessary for the synthesis and balance of various female hormones, which is especially important during pregnancy as it affects the maintenance of the pregnancy and child development. Additionally, since the baby is entirely dependent on the mother's fat stores, and fats are essential for building tissues, a deficiency can lead to miscarriage or other negative effects on the baby. Finally, a poor ratio of essential fatty acids, omega-3 and omega-6, leads to slowed baby development and placental inflammation, which can cause a series of permanent disorders in the child.

Significant sources of healthy fats include: olive oil, avocados, nuts, seeds, eggs, and fatty fish. Reaching a good amount of total fats is not an issue with a varied and regular diet. Problems with total fats can occur if a pregnant woman follows specific restrictive dietary regimes that are neither balanced nor designed for expectant mothers.

On the other hand, the problem of the omega-3 to omega-6 ratio is highly prevalent in the general population as well. A good way to meet omega-3 needs is to consume fatty fish twice a week. However, based on practical experience working with people from our region, I guarantee that most individuals do not have this habit. The reason for this might be the price and availability of fresh fish, but it is also a consequence of culture and habits. For this reason, I frequently recommend omega-3 supplementation in the form of fish oil. Two specific fatty acids that everyone needs—especially future mothers—are DHA and EPA, and they can be found as supplements in all pharmacies. The recommendation of the European organization EFSA is to intake between 250 and 500 milligrams of these fatty acids daily, which you can check on the supplement packaging, though even larger amounts show no negative effects.

Vitamins

While in impoverished countries in Africa and Asia there are many vitamins that pregnant women frequently lack, in Europe and America this is a much rarer issue. The reason is access to a varied diet throughout the year, as well as supplementation and fortification, which are established practices today, especially during pregnancy. However, inadequate intake of certain vitamins remains a problem in developed countries too, particularly vitamin D and folates.

A deficiency in vitamin D (vitD) is the most common vitamin deficiency among pregnant women worldwide. It is estimated that, depending on the country and culture, 18 - 84% of expectant mothers have this deficiency. While data for Serbia does not exist, data for the US, for example, shows a 5 to 50% prevalence of insufficient vitD levels in the blood of pregnant women.

A vitD deficiency during pregnancy has adverse effects on the woman and the fetus, and later on infants and children. This vitamin is highly significant for practically all organs and organ systems, and a prolonged deficiency leads to many problems, most notably rickets and other bone and calcium metabolism issues. Other complications include weakened immunity, the development of arthritis and asthma, type 1 diabetes, and an increased risk of several types of cancer.

VitD is obtained in two ways: through diet and through skin exposure to sunlight. Today, we spend most of our time indoors, which was unthinkable just 50 years ago. Additionally, food that used to be rich in vitD, like eggs or wild mushrooms, contains significantly less of this vitamin today or is rarely eaten. This brings us to the necessity of monitoring vitD status and adding supplements if needed. I think it would be excellent if checking vitD at the beginning of pregnancy and every 3 months after that was a normal, routine practice, but it isn't. For this reason, it is best to occasionally do a private lab check for vitamin D status, which won't cost more than 2000 dinars. Then, if vitD is below a healthy value, it should be supplemented, and it is best to consult a doctor about this. General guidelines for adequate vitD supplementation remain very outdated and small in quantity, from 200 to 400 IU, but more realistic and useful vitD supplements ranging from 1000 to 4000 IU can be found in pharmacies. These concentrations of vitD are safe to use and help restore the body's reserves once a deficiency is noticed. So, occasional lab testing and supplementation seem to be the best solutions.

Folic acid or vitamin B9 plays several crucial roles in maintaining human health and well-being, including blood cell production, DNA synthesis, cell development, and proper brain and neuron function. Among the general population in developed countries, a deficiency rarely occurs due to the frequent and substantial presence of this vitamin in everyday foods. However, during pregnancy, requirements for folates shoot up due to the rapid construction of new tissues and the expansion of total blood volume. A deficiency during pregnancy is linked to disruptions in the health of both mother (anemia) and child (cognitive changes).

Good dietary sources of folate are green leafy vegetables and legumes, but the World Health Organization recommends that all women planning a pregnancy orally supplement an extra 400 micrograms of this vitamin. If you take any prenatal supplements during pregnancy, it is almost certain that folates are already included in them, so there is no need for additional supplementation.

Minerals

As with vitamins, mineral deficiencies are less frequent in developed countries than in underdeveloped ones due to constant access to a varied food supply. However, iron and iodine deficiencies remain common problems across the globe, which can significantly impact the health of the mother and child.

Iron is a micronutrient that the body uses to produce red blood cells. Just as with folates, this means that iron requirements during pregnancy increase significantly due to the expansion of blood volume. Unlike folates, iron deficiency is common throughout the developed world, and in European countries, it is observed in 4 to 33% of the general population aged 16 to 50. Additionally, because of the heightened demands in pregnancy, it is estimated that only 20 to 35% of women of reproductive age have enough reserves to carry out a pregnancy without supplementation.

In a diet, significant amounts of easily accessible iron can be found in meat, especially organ meats, and seafood. Less accessible iron in significant quantities is found in legumes, green leafy vegetables, nuts, and certain fruits. Interestingly, iron absorption from food can be enhanced by consuming vitamin C before a meal, especially a meat-rich meal.

The World Health Organization suggests daily supplementation of 30 to 60 milligrams of iron, from conception to the end of pregnancy, regardless of the pregnant woman's conditions and habits. Higher amounts of iron supplements may be necessary if there is an elevated risk of anemia.

Iodine is a mineral essential for the normal function of the thyroid gland and proper fetal development. During pregnancy, iodine requirements rise by about 50%. A severe and long-term iodine deficiency leads to a whole spectrum of anomalies in the baby's development, including cognitive abnormalities, growth retardation, and miscarriage.

The most significant source of iodine in the diet is iodized salt, though it is also found in marine fish and seafood, dairy products, and eggs. Also, iodine is present in most prenatal supplements, and even without that, using iodized salt is sufficient most of the time. Iodine status can be checked in laboratories, and if it falls below the required limits, it can be quickly replenished through one-off or continuous therapy.

What to avoid during pregnancy

There are several types of food items that should be avoided during pregnancy for various reasons. Most are either obvious or very specific, so I will just list them with a brief explanation and without too much debate over how problematic they are.

Raw meat and fish are very rare in our diet, so you only need to avoid a few dishes, including raw steak, steak tartare, and sushi. The issue with raw meat and fish is that they can carry pathogens dangerous to the mother and child, which would otherwise be destroyed by thermal food processing.

Unpasteurized milk and products made from unpasteurized milk stand as a warning on every pregnancy website. However, this practically just means avoiding unboiled domestic milk and cheeses if they are made from unboiled milk (like Sjenica cheese). The reason is, again, parasites—specifically salmonella, which is particularly dangerous during pregnancy.

Liver can be problematic due to high amounts of vitamin A and other vitamins and minerals. Since absorption efficiency increases and liver contains a lot of vitamin A, it can lead to hypervitaminosis—an excessive intake of this vitamin—which can be toxic to the mother and child.

Caffeine is acceptable in normal amounts, but you should be aware that a portion of caffeine crosses the umbilical cord to the baby, creating the same effects of alertness in them as it does in adults. The recommendation is not to exceed an intake of 200 to 300 milligrams of caffeine, which is roughly two to three espressos per day.

Alcohol, cigarettes, marijuana, and other substances should be avoided during pregnancy for obvious reasons. Any substances that do something to our brain will do something to the baby's brain as well. Special attention should be drawn to marijuana, which some pregnant women use to alleviate pregnancy pains, nausea, and insomnia. Cannabis use can be harmful to the baby because the active substance in cannabis, THC, reaches the baby through the umbilical cord and can cause slowed growth and abnormal neurological development.

Highly processed food is a group of products that should generally be avoided or consumed only occasionally. This is particularly important during pregnancy because some substances added during food processing can be highly harmful, while others can hinder the absorption of other nutrients from food. You can recognize highly processed food in several ways: it contains a large number of ingredients (20+), lasts a very long time outside the freezer, and it is not easy to tell what it is made of, except by the picture on the packaging. Some examples of such food include ready-made and frozen meals, sweets and snacks, processed meats, and the like.

Conclusion

After reading this text, it might seem like you need to watch out for a million things during pregnancy and make massive changes to your diet, which is not true. If you already have varied and regular meals, all that is needed is a bit of extra supplementation. If your current diet is on the poorer side, you should try to expand the list of foods you use during pregnancy, but you shouldn't experiment too excessively.

The body knows very well what it is doing, and your job is not to overthink everything, but simply to support the body by giving it good materials to work with. While it is possible for a pregnancy to pass smoothly even without supplementation, modern technologies have given us the option to avoid numerous problems with very little effort. The point is that while supplements can help, they are not the most important thing, and a good diet must take precedence.

Finally, perfection is a poor goal, and it is crucial to focus on consistency. Nine months is a marathon race, and throughout the entire period, you should choose good ingredients, but also look after yourself. If you have a craving for some bad food, it is fine and fully expected; satisfy it and move forward with good choices. Choosing good food during pregnancy is a way to show love and care to your baby even before birth.