Nutrition and Exercise in Pregnancy

A Breakdown of Nutrition and Exercise by Trimester

Adequate nutrition, and safe exercise during pregnancy is vital in ensuring the health of you, and your baby. This blog works through each trimester, highlighting the most important things to focus on in nutrition and exercise.

This starts with the preconception period. Research has been very clear that the things you do before you are pregnant can affect your future pregnancies, and children. When it comes to pregnancy, and the health of your future children, we want to reduce any controllable risk factors we can for adverse health outcomes. 

When planning for pregnancy the NHMRC (National Health and Medical Research Council) recommends you should be taking a prenatal supplement or thinking about your preconception nutrition 3 months prior to trying to conceive. Ideally, this will be 3-6 months prior, and up to a year if you are transitioning off contraception. Improving your nutritional status PRIOR to conception can help avoid delays to conception, support ovulation, and prevent nutrient deficiencies in pregnancy, especially in the first trimester when nausea and vomiting may be present.

To read more about the importance of a good diet during pregnancy click here.

TRIMESTER 1 (0-12 weeks)

Nutrition

In the first trimester, many people undergo the common pregnancy symptoms of nausea, vomiting, and extreme fatigue. The expected gestational weight gain during the first trimester is only 0.5 – 2kg overall for the entire first trimester. Energy needs don’t increase greatly in the first trimester, so it is more about focusing on specific nutrients.

One of the main nutrients is iodine. Iodine is involved in the development of the thyroid hormone. The thyroid hormone is involved in regulating your metabolism and has a key role in brain growth and development. During pregnancy your iodine requirement increases as your thyroid activity increases. We can find iodine in seaweed, dairy products, eggs, and seafood.

Another nutrient that is important in your 1st trimester is folate or folic acid. Folate, also known as vitamin B9, is essential for healthy growth and development as it contributes to DNA synthesis, cell repair and growth. If you’re wondering what the difference is between folic acid and folate, well folic acid is the form commonly found in supplements, where folate is naturally occurring in foods such as leafy greens, legumes, cruciferous vegetables (think broccoli, and brussel sprouts).

The main goal for trimester one is to be consistent with your prenatal vitamin. If you are suffering from mild to moderate levels of nausea, vomiting and fatigue, we are most concerned about whether you can keep your prenatal vitamin down, and maximise on your intake during the times you are feeling better.

And what about physical activity, and regular exercise during pregnancy? 

Exercise

Research has demonstrated that, for women without complicated pregnancies, exercise is beneficial and helps to reduce the risk of pregnancy complications such as pre-eclampsia and gestational diabetes! As the body undergoes major changes on a physical, hormonal and energy level, it is important to consider how exercise may look a little bit different to before.

Guidelines suggest that pregnant women should aim to be active most days of the week for at least 30 minutes at a moderate intensity, including both aerobic and strength training. This adds up to a total of 150-300 minutes of exercise per week. Exercising at a moderate intensity is equivalent to keeping your heart rate below 90 % of your maximum, and using the “talk test”. The “talk test” means, if you can comfortably hold a conversation during exercise the intensity is considered to be moderate, it is also a great way to gauge and adjust exercise intensity!

Within the first trimester, cardiovascular and respiratory capacity changes take place, meaning the heart rate and oxygen consumption increases. These physical changes combined with common pregnancy symptoms such as nausea, vomiting and fatigue, may mean that exercise capacity is reduced due to depleted energy levels. Additionally, the body’s ability to regulate temperature is affected during pregnancy, particularly in the first trimester, therefore being mindful of not overheating with exercise and drinking plenty of water.

TRIMESTER 2: (13-27 weeks)

Nutrition

During trimester 2, hopefully your appetite has come back and most of the nausea and vomiting has subsided! Now is the time that you can actively prioritise your nutrition!

Increased food groups: Our grains food group goes up by 2.5 serves, and your protein food group goes up by 1 serve in pregnancy. For this reason, we advise that you add another snack or two to your day to bump up your energy and work towards meeting your nutritional need

Calcium and Vitamin D: The growing baby takes calcium from the mother’s stores for bone growth, teeth (eventually) and bodily processes. We need calcium from our diet as our bodies can’t produce it. Vitamin D goes hand in hand with calcium as it assists with calcium absorption. So, enjoy some time on a daily walk and get some sunshine!

B12: This interrelates with trimester 1 and 2 really. All our B vitamins aid in energy production and conversion, however B12 and folate (B9) rely on one another to work correctly. Women are often aware they need to consume folic acid. Consuming high levels of folic acid can mask vitamin B12 deficiency, so it is important that you are having a visit with your GP, and expert prenatal dietitian WELL BEFORE you conceive.

Exercise

As energy levels begin to return during the second trimester, exercise output can too. If you have a history of strength and aerobic based training, guidelines recommend keeping it up as able!

Strength training is a great and fun option. It can also help to manage skeletal and postural changes that occur during pregnancy. Things to keep in mind include; keeping the weight at a comfortable load, now is not the time for lifting your personal-best, and avoiding lifting with a heavy breath hold, brace or valsalva manoeuvre. There are so many ways to modify exercises, such as switching from bare-bells to dumbbells, using resistance bands, reducing repetitions and range of motion to suit where you are at!

Let’s talk about aerobic training, particularly running. If you have a previous history of running, often it is safe to continue doing so during the second trimester. You may need to consider modifications such as pulling back on your distance, staying hydrated and taking regular interval breaks. It is important to be mindful of the impact that running and other high impact exercise has on the pelvic floor muscles and connective tissues, symptoms of leaking urine and feeling heaviness in the pelvis is when you should stop and seek specific medical advice. Otherwise alternative aerobic exercises can include swimming, stationary cycling, dance class and walking.

Guidelines suggest that from the second trimester exercises requiring you to lie on your back for a prolonged period of time should be avoided. due to risks of compromising blood flow to you and your baby. Other exercises to be mindful of are those that cause “coning” through your core, in other words exercises where you aren’t achieving good pressure control through your abdomen, these exercises may include rowing machine, sit ups, planks

TRIMESTER 3: (28-40 weeks)

Nutrition

The third trimester is all about preparing for the postpartum period. Specifically the first 6-8 weeks postpartum, when you are just absorbing all the new changes that have occurred in your body and your life!
There are three key things of focus in the third trimester, the first isn’t quite a nutrient, but it is A BIG ONE.

IT’S FIBRE
The hormone progesterone increases in pregnancy and slows the gut down and causes your food to move through a little slower. Constipation can be present at any point in pregnancy, however prior to birth it is crucial that your bowels are working regularly and you’re able to easily pass your poo!

Regardless of how your baby enters the world (vaginally or via c-section), you are going to need to be very careful with the first few bowel movements, and it will be a “no pushing allowed” situation. Fibre is found in your wholegrain carbohydrates, fruit, vegetables, and legumes.

Iron
Iron deficiency affects 20% of the pregnant population. During pregnancy, a person’s blood volume increases by up to 50% to support both mother and baby. Low iron levels can contribute to greater levels of fatigue, low concentration and in some cases a reduced ability to fight off infection. The final 10 weeks of pregnancy are most important for iron as it sets up 100% of your baby’s iron stores until they begin solids at around 6 months.

Fish Oil
If you are taking fish oil, or an omega 3 supplements it is recommended that you stop taking these at 35 weeks. This is to reduce the risk of bleeding associated with taking high amounts of fish oil supplements. This risk is quite low, and there is still more research needed in terms of relationship to pregnancy and risk of bleeding; however, it is much better to exercise safe and conservative practices.

In the third trimester, you are able to have a healthy diet, with a wide variety of fruits, vegetables, wholegrains and healthy fats. The weight gain guidelines during pregnancy will vary depending on your situation (e.g. pre-pregnancy weight, twin or triplet pregnancy, etc) so it is helpful to check in with a pregnancy dietitian for what you should be aiming for by the end of pregnancy.

Read more about how to nourish your body for breastfeeding here

Exercise

The third trimester is a great time to continue embracing the benefits of exercise, keep modifying your exercise load, intensity and volume. Modifications may include using walls instead of the floor for push ups, boxes to reduce your squat depth, walking instead of running, double leg instead of single leg exercises.

If you haven’t already, the third trimester is also a great time to start to consider your pelvic floor muscles. The pelvic floor is made up of two layers of muscles, a deep and superficial layer, during pregnancy these muscles begin to stretch and soften as your baby continues to grow and your body prepares for child birth. These changes not only occur to the muscles, but also other support structures, or connective tissue, supporting our pelvic organs.

Research suggests that doing pelvic floor exercises during pregnancy may help to reduce the rate of first and second stage of labour. It is a good time to consider seeing a pelvic floor or women’s health physiotherapist to ask about your pelvic floor function, review bladder and bowel habits, discuss your birth plan and considerations during your postpartum recovery.

There are a few maternal conditions and medical risks during pregnancy that should be screened to ensure women are guided appropriately. At all times listening to your body is so important, and watch out for severe warning signs to stop exercising such as; vaginal bleeding, regular painful contractions, amniotic fluid leakage, headaches, chest pain, muscle weakness, calf pain or swelling, prolonged shortness of breath.

CONCLUSION:

When it comes to pregnancy, it is important for you and your baby to include adequate nutrition and movement. The most important thing is to surround yourself with support, to listen to your body (and your baby) and to seek out advice and help when you need it.

Feeling like you need some individualised help with your nutrition in pregnancy? Book in for an initial consultation here.

This blog post was co-written by Erin Cuskelly and the team at Female Focus Physiotherapy. You can follow them on Instagram @femalefocusphysiotherapy and book an appointment with one of the amazing physiotherapists here.