While women of all weights can successfully get pregnant, being underweight or obese may cause irregular menstrual cycles and ovulation, making it more difficult to conceive. A healthy pre-pregnancy weight is also associated with lower risk of pregnancy complications.

Nutrients You Need During Preconception and Pregnancy

Changing your diet in healthful ways prior to conception benefits you and supports healthier eating habits during your pregnancy. While the amount of food (and calories) you need to consume prior to conception and in the first trimester does not actually increase, your nutrient needs do.

Satisfy these increased nutrient needs by eating high-quality foods (think whole, minimally processed foods). So while it may be tempting to “eat for two,” instead try “thinking for two” and upgrade your dietary choices without overdoing your total dietary intake.

Here are the nutrients to focus on to improve the lifetime health of you and your baby (and check out the What to Do section for tips on getting them into your diet):

• Folate – Healthful diets with adequate folate may reduce a woman’s risk of having a child with neural tube defects. The neural tube becomes your baby’s brain and spinal cord. Folate is especially critical during the first trimester so make sure you’re getting enough from the start of your pregnancy, and ideally, several months before you conceive.
• Iron – During pregnancy, you need extra iron to help your body make more blood to supply oxygen to your baby. And your baby will build iron stores in the womb that will last him for the first six months of life. Too little iron during pregnancy can be problematic for your baby’s brain development and can lead to anemia.
• Calcium – Although your calcium needs do not increase during pregnancy, calcium is still important for your own health and for your baby’s bones and teeth. Make sure you are getting adequate amounts, preferably through your diet, or else your body may take the supplies from your bones for your baby, which can put you at risk for osteoporosis.
• Zinc – Zinc is essential for tissue growth, which your baby will be doing a lot of!
• Vitamin D – Vitamin D works with calcium to help your growing fetus develop strong bones and teeth.
• Iodine – Iodine is essential for the thyroid (both yours and your baby’s once it’s formed), which is important for neurological development. Many women don’t get enough iodine because so much of our sodium intake comes from processed foods and fast foods made with non-iodized salt.
• Choline – Choline is truly critical during preconception and pregnancy. Your body can’t make it so you will need to rely on food or supplements to ingest the proper amount. Like folate, it helps develop the neural tube, which becomes your baby’s brain and spinal cord. A high-choline diet may improve how well the placenta functions and protect the baby from environmental toxins.
• Essential fatty acids (EFAs) – EFAs are polyunsaturated fats considered “essential” because of the body’s inability to produce these important nutrients on its own. EFAs come in 2 groups: omega 3 fatty acids and omega 6 fatty acids, each with its own subgroups.
  Omega 3 is especially important for optimal fetal, infant, and early childhood growth but most Americans tend to have diets low in omega 3’s. To up your intake, focus on including low mercury fish, nuts and seeds in your diet and consider a supplement (speak with your doctor) if you do not consume many of these foods. DHA, EPA and ALA make up the family of omega 3s. DHA is the major omega 3 involved in the development of the brain, nervous system, and retina.
  In contrast, omega 6 fatty acids are consumed regularly in the typical American diet being that they primarily come from plant oils such as corn, soybean, and sunflower.

What to Do

Take a prenatal vitamin

In addition to following a healthy eating plan, take a prenatal vitamin to help ensure you are meeting your daily nutritional requirements for vitamins, minerals and micronutrients.

Find out what a healthy preconception weight is for you by speaking to your healthcare provider.

The recommendations for weight gain during pregnancy are based on your pre-pregnancy body mass index. Calculate your BMI by dividing your pre-pregnancy weight in kilograms by your height in meters, squared (or just use an online BMI calculator). And note that BMI calculations offer helpful guidelines but are not perfect indicators of healthy weight so always talk with your healthcare provider.

Here’s a weight guide according to BMI:

• BMI of below 18.5 = underweight
• BMI of 18.5 to 24.9 = normal weight
• BMI of 25 to 29.9 = overweight
• BMI of 30 or greater = obese

Use preconception to develop healthy eating and lifestyle habits that will carry you through pregnancy and beyond

The Dietary Guidelines and My Plate, which emphasizes choosing healthy foods in appropriate relative proportions, is a great tool for promoting healthy habits that will optimize health. It recommends filling ½ of your plate with vegetables and fruit (and more of the former than the latter), ¼ of your plate with whole grains and ¼ of your plate with lean protein.

Other important considerations are choosing healthy fats (like those found in nuts, seeds, olive oil and avocado), emphasizing water and getting adequate physical activity.

Get plenty of micronutrients

Your needs for many micronutrients increase significantly during pregnancy. To learn more about just how much you need of each nutrient read Recommended Intake for key nutrients: pre-conception, pregnancy and postpartum and consult with a primary healthcare provider to learn about the many ways to satisfy your specific intake needs. Focusing on incorporating these foods into your diet while pregnant will help you meet your nutrient needs and improve the lifetime health of you and your baby:

• Find folate in many foods such as vegetables (especially dark leafy green veggies), fruits, nuts, beans, dairy and meat.
• Find iron in beef, white beans, eggs, spinach, lentils, and fortified grains. Your body absorbs iron best from plant sources if taken with a good source of vitamin C (for example, pair iron-rich cereal with strawberries or beans with tomatoes).
• Low-fat dairy, dark leafy greens, tofu, baked beans, almonds, sardines, sesame seeds and figs all contain calcium. Many cereals are now fortified with calcium too, so check the labels.
• Get your zinc from meat, beans, nuts, whole grains, and dairy.
• It can be difficult to reach the recommended amount of vitamin D from diet alone, but the best sources are fish and fortified dairy products.
• Seafood, dairy and iodized salt are your best sources for iodine.
• Eggs, beef, salmon, and quinoa are all great sources of choline.
• EPA and DHA come primarily from fish (or fish oil supplements), while ALA comes from vegetable, soybean, and canola oils; flaxseeds; walnuts; and grass fed meat. While there are other benefits to eating ALA-rich foods, our bodies don’t get direct omega 3s from ALA, instead we have to convert ALA to EPA and DHA. So unless you’re vegan or a vegetarian who doesn’t eat fish, fish is the best source of omega 3s.
• Omega 6 fatty acids are found in several oils including canola, flaxseed, corn, sunflower, safflower, and soybean. You can add some of these plant oils in your salad dressings and while cooking so that you are getting adequate omega 6s.

Eliminate potentially dangerous substances once you start trying to conceive

Drugs, alcohol, tobacco and second- and third-hand smoke should be avoided during pregnancy. Because most women don’t know exactly when they become pregnant, it’s best to avoid these products if you are trying to conceive to optimize your baby’s (and your) health.

Work toward decreasing your caffeine intake as well. The American Congress of Obstetricians and Gynecologists (ACOG) recommends limiting your caffeine intake to no more than 200mg per day while pregnant – depending on cup size, that’s approximately the amount of caffeine found in 1-2 cups of coffee. Remember to add up all sources of caffeine — from food, beverages, and medications — to make sure that you’re not exceeding the 200mg per day limit, and see Do’s and don’ts of caffeine in pregnancy for even more info.

Make sure you are getting enough essential fatty acids

Eat regular amounts of fish, along with some grass-fed beef and walnuts, in order to get your omega 3s and regular amounts of simple plant oils to get your omega 6s. And to talk with your healthcare provider about taking omega 3 supplements and specifically, DHA, given that dietary amounts are usually suboptimal.

Choose your fish wisely

Fish is an important source of a number of high-quality nutrients, from protein to essential fatty acids, so don’t avoid all fish, but do avoid fish recognized as having high amounts of methylmercury, like shark, white tuna, swordfish and king mackerel. Instead, aim to eat 12 ounces each week of these lower mercury fish: wild salmon, canned light tuna, shrimp, tilapia, and sardines.