What to Eat During Pregnancy: Trimester-by-Trimester Guide
When I first found out I was pregnant, I was excited, overwhelmed, and let’s be honest, a little panicked about what I was supposed to eat. As a first-time mom, there’s already so much to learn. Add in twin nutrition, and suddenly you're googling ‘how much protein do twins need?’ at 2 a.m. with a bag of crackers in hand. Sound familiar?
Now, as a prenatal dietitian, I get to help twin moms navigate this journey with clarity, confidence and zero shame. Let’s walk through what to eat in each trimester of your pregnancy because nutrition should feel empowering, not exhausting.
First Trimester
Although not all women experience morning sickness in pregnancy, most women experience some degree of nausea as a result of elevated pregnancy hormones, particularly human chorionic gonadotropin (hCG) and progesterone. The good news (and yes, there is good news) is that some small tweaks to your diet can help lessen symptoms and make you feel better.
Folate
One of the most important nutrients for the first trimester and possibly the only nutrient you will hear your doctor talk about, is folate: an essential B vitamin that plays a role in preventing neural tube defects in pregnancy, such as spina bifida and anencephaly. Spina bifida is a birth defect where the spinal cord does not close completely during pregnancy and exposes part of the spinal cord and nerves. Anencephaly is a severe birth defect where the brain and skull do not develop properly. Neural tube defects can cause lifelong complications and are even fatal. A baby's neural tube closes within the 3rd and 4th weeks of pregnancy, after conception making it important that pregnant women pregnant prioritize folate early on in their pregnancy. Folate-rich foods include black-eyed peas, Brussels sprouts, avocado, spinach and mustard greens. Many breakfast cereals and grains are also fortified with folic acid to help reduce risk of deficiency.
Vitamin B6
It’s so important that you know you don’t have to suffer through morning sickness for months on end in your pregnancy. Eating a vitamin B6-rich diet can help you manage nausea and morning sickness. Vitamin B6-rich foods include chickpeas, salmon, chicken breast, potatoes, turkey, bananas and ground beef. Many vitamin B6-rich foods are also great sources of protein which helps to maintain stable blood sugar levels and prevent nausea.
Iron
Pregnant women have significantly higher iron needs than non-pregnant women, making anemia a true concern. Anemia in pregnancy increases the risk of preterm birth and low birth weight babies. Diet can play a role in reducing the risk of preterm birth in a twin pregnancy. For actionable guidance to reduce your risk of preterm birth, you can read the full article here. Iron needs increase in each trimester, so it is important to focus on iron-rich foods early and often. Iron-rich foods include oysters, beef, salmon, sardines, chicken, beans, spinach, lentils and fortified grains.
Iodine
Iodine is essential in the first trimester of pregnancy because it supports the synthesis of thyroid hormones and in the first trimester, babies cannot produce their own thyroid hormones yet. Thyroid hormones support fetal brain development, regulate metabolism and support cognitive function. Maternal iodine intake is crucial in preventing fetal developmental and cognitive impairment in pregnancy. After the first trimester, your baby can produce their own thyroid hormones and don’t depend entirely on your intake. Iodine-rich foods include seafood, seaweed, dairy products, eggs and iodized salt.
Second Trimester
In the second trimester, you might be feeling more energized and your food aversions might be easing up. This is a great time to focus on your diet to help you reduce potential complications such as preterm birth, preeclampsia and small-for gestational-age.
Calcium
In the second trimester, calcium is an important nutrient to focus on for many reasons. First, calcium supports the growth and development of your baby’s bones, but it also supports your own bone health. If moms aren’t eating enough calcium in their diet in pregnancy, their babies will pull calcium from their bones to ensure their needs are being met. This can result in poor bone health as you age, increasing risk of osteoporosis. Calcium intake can also help to reduce your risk of preeclampsia in pregnancy. Preeclampsia is a pregnancy complication characterized by high blood pressure and protein in the urine which can result in preterm birth and health complications later in life. Calcium-rich foods include sardines, yogurt, kefir, milk, dark leafy greens, tofu and fortified beverages.
Protein
As morning sickness lessens or potential food aversions lighten it, it can be easier to focus on protein in the second trimester. Pregnant women need anywhere between 10-150 grams of protein per day to support the growth and development necessary in pregnancy. Protein supports the growth of everything including organs, muscle, bones, skin, enzymes and hormones. Adequate protein intake can help you manage nausea, reduce fatigue and support stable blood sugar.
Glycine
For non-pregnant women, glycine is a non-essential amino acid, meaning we can make enough on our own without needing extra in the diet. In pregnancy, it becomes conditionally essential, meaning we need to eat more glycine-rich foods to support the increased needs for both mom and baby. Glycine supports your growing uterus, fetal organ development, bone growth and supports blood pressure balance. Pregnant women need nearly 10x more glycine than non-pregnant women and it needs to be obtained through the diet. Glycine-rich foods include slow cook meats, collagen powder, gelatin powder, poultry with the skin, ground meat and pork rinds.
Third Trimester
In the third trimester, you may notice a whole new array of symptoms such as fatigue, heartburn and nausea (…again). You might also notice increased hunger, but that you get full really fast. This can make eating a balanced diet more challenging, but it is most important to simply do your best and take it one day at a time.
Omega-3s (DHA)
In the third trimester, your baby’s brain is going to grow three times in size. One crucial nutrient to focus on is the omega-3 fatty acid, DHA. Consuming DHA throughout pregnancy supports this rapid brain development, cognitive function and can help reduce the risk of preterm birth. Some of the best sources of DHA include seafood such as salmon, sardines, mackerel, oysters and mussels. For more guidance on safe-to-eat seafood in pregnancy, check out this blog post here.
Magnesium
It is estimated that about half of Americans are not eating enough magnesium in their diet likely due to insufficient intake and aggressive farming practices that leave the soil magnesium-depleted. In pregnancy, women who experience frequent muscle cramps, pregnancy insomnia and gestational diabetes have a greater risk of magnesium deficiency. Eating enough magnesium in the diet can also help to decrease the risk of preeclampsia. Magnesium-rich foods include dark leafy greens, pumpkin seeds, sunflower seeds, sesame seeds, almonds and peanuts.
Fiber
Constipation in the third trimester can be a result of many things including the uterus compressing against the stomach, hormonal changes or your current supplement regimen. By eating a fiber-rich diet, drinking enough fluids and re-evaluating your supplement regimen, constipation isn’t something you have to “just deal with.” Fiber-rich foods include berries, pears, apples, avocado, beans, broccoli and green beans. Start by introducing one fiber-rich food into your diet and gradually increasing as tolerated to prevent uncomfortable gas and bloating.
Reminder: You’re Doing Amazing
Whether you're barely eating or eating everything in sight, there’s no one perfect way to eat in pregnancy. Every pregnancy is different and you know your body best. That said, a little support goes a long way. That’s exactly why I created Baby Bump Bootcamp! If you’re overwhelmed by what to eat, how much or how to prep for postpartum… I’ve got you.
Baby Bump Bootcamp is my signature 8-week program for moms-to-be, which includes:
A complete pregnancy nutrition guide
A recipe book packed with balanced, tasty meals
8 educational video modules (topics like trimester nutrition, preventing preterm labor, postpartum planning, and more)
Two 1:1 nutrition counseling sessions with me, a prenatal dietitian to create your unique pregnancy roadmap
Unlimited email support for all those “can I eat this?” questions
References:
https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/
https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/
