Pregnancy
When it comes to reproduction, nothing in the science of anatomy and physiology is more awe inspiring as pregnancy. For women, we are physically designed to create, host and support the development of a new life. In many ways, our bodies have been “prepped” for this call of duty – storing excess and essential fat in areas we work effortlessly to try and rid of, calcium and minerals in our bones “just in case” – and a huge hormonal and chemical network that operate almost like a generator – providing needed energy if ever there were a “blackout” – or in our prehistoric ancestor’s situation, an unpredictable winter. But thanks to the agricultural revolution and the “dawn of civilization” – most pregnant women today do not need to rely on their stored resources to carry their babies to term. In fact, this overabundance of food may be presenting a whole new set of challenges for pregnancy in the 21st century, and the future health of the unborn baby.
Growing evidence that “they” are what you eat
For ages, nutritional concerns during pregnancy have always been approached on the side of the mother’s. The only concerns for gaining too much weight during pregnancy were focused on the risks of gestational diabetes and the potential complications during labor and delivery. These same risks hold true today, but there are now concerns over the connection between the mom’s diet during and after pregnancy, and on the future food preferences and eating habits of her unborn baby. Yikes! Not very comforting considering pregnancy is notorious for ravenous appetites, indulgent cravings and the age-old sentiment that “eating for two” is not only accepted – but almost expected!
In the midst of an epidemic of childhood obesity, prevention is crucial. Current research shows that prevention should begin as early as gestation. That in fact, mom’s eating feeding patterns and food preferences have a direct affect on the fetus, exposure it to flavors and eating behaviors likely to be inherited (3,4).
A Womb With A View
Eating For Two
To make sense of this, some attention needs to be put on the “accommodations” that you will be providing for your growing guest, and how your behaviors – specifically eating – affect the quality of their environment.
For approximately 40 weeks, your developing baby will exist within the cozy, warm confines of the amniotic sac – or commonly referred to as “the womb.” Surrounded by the buoyancy of amniotic fluid, this environment provides protection from the outside world while allowing your baby the movement needed to develop their muscular and skeletal systems. Amniotic fluid is mainly composed of water, but also contains carbohydrates, lipids, protein, and electrolytes. Although it does not provide your baby with nutrition (that is the job of the placenta!), the amniotic fluid is believed to have an influence on the future food preferences and eating habitsof the developing fetus.
The explanation for this has to do with the ability for certain flavors from your diet to seep into the amniotic fluid and breast milk. At approximately 7 weeks gestation, your baby will begin to develop taste buds and has its first exposures to flavors through those present in the amniotic fluid (1,2,3,4). By 12 weeks gestation, your baby actually begins to swallow and inhale amniotic fluid – a voluntary act and one that is driven, scientists are now determining, by preference.
As humans, we are innately “programmed” to accept sweet tastes - believed to be associated with the quick provision of energy needed for survival, and reject bitter tastes, associated with poison and death. This survival mechanism proved to be most useful to our earliest ancestors in avoiding poisonous berry and plants. Some theorists offer the explanation that the “leaking” of specific plant based flavors (many of which are bitter in taste) into the mother’s amniotic fluid and breast milk was a way to prepare the baby for its diet on the outside. This gradual introduction to safe, bitter-tasting plants could then allow the offspring the ability to recognize safe foods necessary for their survival.
Now – fast forward to the diet of the 21st century. Not quite what our “genetic programmers” had in mind when they created the menu sampling mechanism of flavoring the amniotic fluid. It is believed to be this presence of flavor within the amniotic environment that first exposes the fetus to sugar, salt and fat. And if mom’s diet consists of a lot of sugar, you can believe her amniotic fluid will as well. On ultra sound, a fetus can be seen swallowing and inhaling copious amounts of amniotic fluid after a meal or snack high in sugar, and in the presence of bitter flavors (common to vegetables such as broccoli or spinach), the same fetus will close his lips – clearly exhibiting preference for sweet over bitter.
In a recent study that examined the benefits of consuming adequate vegetables during pregnancy and breastfeeding, it was determined that mothers who did in fact consume particular vegetables throughout pregnancy and during breastfeeding had babies who displayed a quicker acceptance of those same vegetables once solid foods were introduced (4,5,6). Of course modeling healthy eating habits are essential for the long-term success of healthy habit building in our children, it is now evident that this modeling begins as early as conception!
Nutrient Needs During Pregnancy
Raising kids to healthy heights begin during pregnancy! Because your diet has an impact on the immediate and perhaps the future health of your unborn baby, following the recommended guidelines for essential nutrients will ensure both your needs are met (7).
| Nutrient | Pregnancy Requirements | Functions Needed For | Dietary Sources |
| Energy (calories) | 300 additional cal/day Additional, approximately 2500 calories/day for normal, active women | Throughout pregnancy, mom’s body is much like a factory – working hard to support and sustain a new life. Energy, in the form of calories, is needed to fuel this factory and keep it going without having to use other resources, such as protein. | 300 additional calories does not amount to a “lot” of food. This could be incorporated into a morning or afternoon snack. Avoid empty calories – such as soda or candy, which provide lots of calories but with little nutrition in return. |
| Protein | 60 grams, or about 6 oz of lean meats - such as turkey, chicken, pork or beef. | Protein is necessary for the formation of cells needed for rapid fetal tissue growth; protein is also needed to support mom’s growth, which includes the placenta, blood volume and breast tissue. | 3oz of protein is approximately the size of a deck of cards. Other protein sources include: fish, nuts and soy products. |
| Calcium | 1,000 mg | Calcium is required for the development of the baby’s skeleton and tooth bud formation. Inadequate calcium intake could result in pulling calcium out of mom’s stores. | Milk and dairy products are the best form of calcium. Try to include 3 cups of milk or dairy products each day. |
| Iron | 30 mg | During pregnancy, mom’s blood supply increases significantly to support her growth as well as the baby’s. Iron is needed to help carry oxygen in the blood to tissues and cells. Without adequate iron, cells cannot perform properly – and mom runs the risk of becoming anemic. | Iron rich foods include: liver, red meat, poultry, green leafty vegetables, eggs, dried beans and peas. |
| Folic Acid | 600 micrograms | If taken 1 month prior to and within the first three months of pregnancy, adequate folic acid can help prevent neural tube defects by up to 70%. | Sources of folic acid include fortified cereals, green leafy vegetables, asparagus, avocados and orange juice. |
| Water/Fluids | 8 – 12 cups each day | For mom: water is needed to increase blood supply, maintain electrolyte balance and elimination of toxins. For the baby, water is necessary for the constant renewal of amniotic fluid, waste removal and nutrient transport. | Water remains the best choice for hydration. Because it is unsweetened, it maintains neutrality within the amniotic environment and does not add “empty” calories like soda and fruit drinks. |
Roadblocks and Solutions
So it sounds easy, right? Unfortunately, the truth of the matter is this: no “one” pregnancy is the same. Despite the best intentions to eat right, exercise, and gain the appropriate amount of weight, our efforts are sometimes thwarted by unexpected roadblocks.
| Roadblock | Challenge | Solutions | Benefits |
| Nausea and Vomiting | Otherwise known as “morning sickness” – nausea and vomiting typically occur within the first 3 months of pregnancy. Although termed ‘morning’ – nausea and vomiting may occur at any time of the day – making eating at all a challenge – never mind trying to eat healthy! | Experts recommend eating small, frequent meals every 3 hours or so. This helps to avoid hunger from setting in, which brings with it gastric secretions within the stomach that triggers nausea. ‘Morning’ sickness tends to be most common because our bodies are naturally hungry from sleep To ease this, keep crackers by your bedside and eat before you even get out of bed. Best foods to incorporate for small frequent meals are: low fat (avoid anything fried), high protein and easy to digest foods such as fruit, toast and dry cereals. Avoid: concentrated sweets/sugary foods; spicy foods; gas producing vegetables such as cauliflower. | Although focusing on fruits and vegetables may need to wait a bit until the nausea and vomiting subside, choosing to eat small frequent meals low in fat, and sugar will provide a consistent amniotic environment that is not excessive in one particular flavor. Also, eating every 2 to 3 hours help keep energy levels consistent and models a healthy eating pattern for the fetus. |
| Dislike of most vegetables | For women who never liked to eat vegetables before pregnancy – eating them during pregnancy will present an even greater challenge. | Remember – it takes approximately 7 exposures (or 7 servings) per vegetable during pregnancy to have a positive impact on your baby’s eating habits. One solution is to make a vegetable chart – chose 5 vegetables – preferably non-starch vegetables such as broccoli, carrots, asparagus, spinach or peppers. Alternate the vegetables throughout the 40 weeks – so broccoli, for example, should be eaten once every 5 weeks. Aim for 1 cup per week of the “vegetable of the week.” If you chose 5 vegetables, you can then expose your baby 7 times to each flavor during your 40 weeks of pregnancy. Try to avoid heavy cream sauces or casserole versions. | For women who never eat fresh vegetables, this will be a huge improvement to her health, as well as the developing baby’s. This is a very achievable goal – and the benefits are well worth the effort. By simply eating 1 cup a week of alternating vegetables, you are exposing your fetus to “healthy” food choices, which can influence their acceptance post-natally. |
| Junk Food Cravings/Healthy Food Aversions | Cravings for junk food – or food high in sugar, fat and salt are very common throughout pregnancy. Many women who experience such consistent cravings also report an aversion to healthy foods, such as vegetables – even if they typically ate them before pregnancy! The reason for this is not fully understood. But most researchers believe it has to do with our hormone-induced heightened senses, which are more attracted to sweet, salty and spicy over bitter or sour. Other researchers believe cravings could be the result of deficiencies – for example, cravings for red meat is thought to indicate the need for more iron, or chocolate cravings suggest inadequate vitamin B intake. But because fresh vegetables naturally high in vitamins and minerals are seldom craved, this theory remains skeptical. Bizarre cravings for non-food items such as clay, dirt or cigarette ashes, is a condition called pica. Eating any of these non-food items could be dangerous to you and the baby. Discuss these cravings with your doctor. | For cravings of high fat, high sugar and salty foods, moderation is extremely important. Pregnancy shouldn’t be about deprivation of food cravings. However, frequent overindulgence will lead to excessive weight gain and repeated exposure of sugar, fat or salt to the amniotic environment. Eating small frequent meals helps control ravenous cravings and hunger – which are triggers for over consumption. The best strategy for handling junk-food cravings is to plan ahead. If it’s ice cream you crave – choose low fat or frozen yogurt; if it’s salty snacks – opt for ones that have reduced sodium. Fried chips? Go for baked. Also, stick to the portion size on the box or bag, or choose a “small” serving over medium or large. | Food cravings during pregnancy are sometimes unavoidable! By indulging in moderation, you can avoid repeated exposure of sugar, fat and salt in the amniotic fluid. This repeated exposure of flavors as well as indulgent eating behaviors can influence your unborn baby’s future eating habits. By keeping with small, frequent meals with moderate indulgences, you will better manage your weight gain - which means less weight to lose after your baby is born - and model healthy eating behaviors for your baby to follow in his post natal life. |
| Healthy Food is Too Expensive | For many women, fresh produce is either hard to find, or hard to afford. This is a reality in our society and one that makes encouraging healthy eating habits difficult to obtain. | Budgeting for healthy fruits and vegetables may be necessary throughout pregnancy to insure you are meeting the necessary needs for you and your baby’s growth. This may require making shopping lists and deleting unnecessary items in favor of more healthy choices. If you need further resources, log on to www.fns.usda.gov/wic or www.fns.usda.gov/fsp for additional services through WIC or the Food Stamp Program. Frozen produce is an excellent alternative to fresh produce, and retains most of the naturally occurring vitamins and minerals. Canned vegetables are another alternative, however many vitamins and minerals are lost during the canning process. | There is no greater investment than good nutrition during your pregnancy for the future health of your child. The high costs of obesity far exceed any costs associated with early intervention. |
1. J.A. Mannella, et. al., “Garlic ingestion by pregnant women alters the odor of amniotic fluid,” Chemical Senses 20, no. 2 (1995): 207-209
2. GJ Hauser, et. al., “Peculiar odours in newborns and maternal prenatal ingestion of spicy foods,” European Journal of Pediatrics 144, no. 4 (1985): 403
3. B. Schaal, et. at., “Human feotuses learn odours from their pregnant mother’s diet,” Chemical Senses 25 (2000): 729-737
4. JA Mannella, et. al, “Prenatal and postnatal flavor learning by human infants,” Pediatrics 107, no. 6 (2001) 88-94
5. JA Mannella, et. al, “Maternal die alters the sensory qualities in human milk and nursling’s behavior,” Pediatrics 88 (1991): 737-744
6. J Savage, et. al., “Parental Influences on Eating Behavior: Conception to Adolescents,” The Journal of Law Medicine & Ethics (2007) 35:22
7. D Berzy, “Lifecycle Nutrition: Pregnancy,” Manual of Clinical Dietetics (2000): 6; 109-127