Pregnancy guide:
First trimester

Part 1: Your first trimester of pregnancy

Happy couple looking at pregnancy test

The first trimester officially begins on the first day of your last period and lasts until the end of week 12. This means that by the time you find out for sure that you're pregnant, you might already be five or six weeks along.

While the initial few weeks of pregnancy are an exciting time, it’s fine to feel overwhelmed and to have mixed emotions as your body prepares for the coming months of incredible change.

With the advice of Bupa pediatrician Dr Aleksander Lastra, we’ve put together a quick guide to your first trimester, including the emotional and physical symptoms of early pregnancy, nutritional advice, and general tips to help make this time even more enjoyable.

How are you feeling?

There will be many physical and emotional changes during your first trimester; knowing this can help you face the months ahead with more confidence. In the first four weeks of pregnancy, you might not even know you’re pregnant, as you may not have any obvious symptoms. But by seven to eight weeks, you might feel tired or even exhausted due to increased levels of progesterone.

You may also find that your breasts feel sore and enlarged. If you do, swapping your regular bra for a sports bra might help. You may need to go to the toilet more than usual1, while rapidly rising levels of oestrogen and progesterone can give you the ever-dreaded nausea and ‘morning sickness’. These hormonal fluctuations can also trigger heartburn, food cravings and food aversions, as well as impacting your emotional wellbeing.

Mood swings can leave you feeling elated one minute and anxious the next. Try to bear in mind that experiencing a whole range of reactions is perfectly normal, and if you can, seek the support of friends and family and discuss these feelings with those close to you.

Managing morning sickness

Nausea and vomiting – usually referred to as ‘morning sickness’ – are common symptoms of pregnancy, especially in the first trimester. However, as you may well know, morning sickness can occur at any time of the day or night, and not all women experience this, or they experience it to varying degrees of severity.

What can you do to minimise the risk of morning sickness?

  • Keep hydrated by regularly sipping water.
  • Eat regular meals and snacks, but don’t overeat.
  • Choose high-carbohydrate plain foods like bread, rice and pasta, but avoid overly sweet or spicy foods.
  • Opt for cold meals, which may be easier to handle than hot ones. This is because they often smell less, and strong smells can trigger nausea.
  • Consider asking someone else to cook meals, or look for an online service that can do the same, if it’s an option. If not, look for dishes that are easy to prepare2.

While morning sickness is unpleasant, it is perfectly normal and in most cases, nothing to worry about; it usually stops by the time you reach 16-20 weeks of pregnancy3. If your nausea and sickness are severe, talk to your doctor, who might be able to prescribe a short course of anti-sickness medicine that’s safe to use in pregnancy.

Non-prescription options that may help include food and drinks that contain ginger, such as ginger ale or ginger biscuits – or you can simply add ginger to your meals. Acupressure can also help: this involves wearing a special band or bracelet that exerts pressure on your forearm and is thought to trigger the brain to release chemicals that help reduce nausea and vomiting4,5.

When it’s more than just morning sickness

A small percentage of women (less than 1%) suffer from hyperemesis gravidarum (HG)6, a condition that causes severe nausea and vomiting, and may even result in hospitalisation.

This condition has gained attention in recent years, as The Duchess of Cambridge suffered from HG in her first two pregnancies, and was hospitalised for it while carrying her firstborn, Prince George. In fact, HG even led to the early announcement of her third pregnancy, in September 2017, as she was under medical care at Kensington Palace an unable to fulfil official engagements.

The chances of developing the condition are less than 1%, but if you suffer from it once, the chances of having it in subsequent pregnancies are around 15%7.

If untreated, the condition can lead to severe dehydration, weight loss, ketosis (a serious condition that results in build-up of acidic chemicals in blood and urine) and increased risk of blood clots8 so if you can’t keep food or fluids down for 24 hours, feel dizzy or faint, or experience abdominal pain or a high temperature (38ºC or above), seek medical advice without delay.

Fuelling your body

You might already enjoy a balanced diet, but it’s now more important than ever to think about what you eat and how you can support your body’s nutritional needs throughout your pregnancy.

While a balanced diet is advised at the best of times, when you’re pregnant, consuming a variety of healthy foods is key to ensuring you and your developing baby get the right nutrients. “Basically, you need to be following the five food groups,” says Dr Lastra. “[And] eat a lot of fruit, vegetables, lean protein, whole grains and dairy products.”

While looking for ways to increase your intake of calcium, fruits and vegetables, be mindful of the foods that can contain bacteria, parasites or toxins that could harm your developing baby. These include some soft cheeses, shellfish and cured meats. The UK’s National Health Service (NHS) has compiled an ingredient guide to help you when you’re eating in a restaurant or doing your weekly shop. Some of the items on the list of foods to avoid may surprise you.

According to Dr Lastra, coffee lovers needn’t go cold turkey, but you should limit caffeine intake to 200mg a day, which is roughly two cups of instant coffee or one cup of brewed coffee9. Alternatively, opt for reduced-caffeine or caffeine-free alternatives such as green and rooibos tea.

If you normally enjoy a glass of wine in the evening, you may want to explore some alcohol-free options, like alcohol-free ‘mocktails’. Taking time to find some non-alcoholic drinks that you enjoy can give you more choice even beyond pregnancy, and there are plenty of online resources for recipes and inspiration.

For a sweet treat, a few squares of dark chocolate can give you a dose of antioxidants: a recent study found that some types of chocolate can improve placental function10.

Finally, you may want to consider taking a folic acid supplement, as it can help prevent birth defects11. The UK’s National Health System (NHS) recommends consuming 400mcg (micrograms) of folic acid every day until 12 weeks of pregnancy. Meanwhile, the UK Food Standards Agency (FSA) recommends that pregnant and breastfeeding women take a daily 10mcg supplement of vitamin D12.

Time to prepare

As soon as you think you might be pregnant, contact your doctor to start organising antenatal (also known as prenatal) care. Expect to attend your first ultrasound scan between eight and 14 weeks. Often referred to as a ‘dating scan’, this is when the sonographer will estimate the due date based on the foetal measurements. However, as Dr Lastra advises: “The due date from this first scan is not always accurate. It’s at the 21-22 week ultrasound that you’ll get a more precise gestational age.”

Now is also the time to consider your birthing options. Would you prefer to be at home or in hospital? Being prepared and exploring all options can help you to relax and enjoy the life-changing path ahead.


1. NHS (http://www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-weeks-4-5-6-7-8.aspx), last accessed in November 2018

2. NHS (http://www.nhs.uk/conditions/pregnancy-and-baby/pages/morning-sickness-nausea.aspx), last accessed in November 2018

3. NHS (http://www.nhs.uk/conditions/pregnancy-and-baby/pages/morning-sickness-nausea.aspx), last accessed in November 2018

4. British Acupuncture Council (https://www.acupuncture.org.uk/public-content/public-pr-press-releases/acupuncture-and-pregnancy.html), last accessed in November 2018

5. BBC (http://www.bbc.co.uk/news/health-36586665), last accessed in November 2018

6. Pregnancy Sickness Support (https://www.pregnancysicknesssupport.org.uk/help/women-suffering/hyperemesis-gravidarum/), last accessed in November 2018

7. Evening Standard (https://www.standard.co.uk/lifestyle/health/what-is-hyperemesis-gravidarum-kate-middletons-severe-morning-sickness-during-pregnancy-explained-a3626646.html), last accessed in November 2018

8. NHS (http://www.nhs.uk/Conditions/pregnancy-and-baby/Pages/Severe-vomiting-in-pregnancy-hyperemesis-gravidarum.aspx), last accessed in November 2018

9. Baby Centre (http://www.nhs.uk/conditions/pregnancy-and-baby/pages/morning-sickness-nausea.aspx), last accessed in November 2018

10. Science Daily (https://www.sciencedaily.com/releases/2016/02/160201214629.htm/), last accessed in November 2018

11. NHS (http://www.nhs.uk/Conditions/pregnancy-and-baby/pages/vitamins-minerals-supplements-pregnant.aspx), last accessed in November 2018

12. NHS (https://www.nhs.uk/conditions/pregnancy-and-baby/vitamins-minerals-supplements-pregnant/), last accessed in November 2018

Bupa Australia (http://theblueroom.bupa.com.au/families/pregnancy/tips-to-look-after-yourself-during-pregnancy), last accessed in November 2018

NHS (http://www.nhs.uk/conditions/pregnancy-and-baby/pages/foods-to-avoid-pregnant.aspx), last accessed in November 2018

NHS (http://www.nhs.uk/conditions/pregnancy-and-baby/pages/morning-sickness-nausea.aspx), last accessed in November 2018

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