What to Expect in the First Trimester

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Published On
17 Jul, 2023
Read Time
6 minutes

As a parent-to-be, early pregnancy can be an exciting time, but it's also a critical period for the growth and development of the baby.

The truth is, the first trimester can sometimes bring some of the most difficult pregnancy symptoms, and we understand it can be overwhelming. That's why we've created this guide to help you navigate through the first trimester.

We'll discuss common symptoms, offer practical advice, and provide answers to some of the most frequently asked questions about the first trimester of pregnancy.

What is the first trimester of pregnancy?

Three trimesters make up a pregnancy. The first trimester sees foetal development start with the egg being fertilised and ends when the foetus has all its organs, and its body systems are developing. After the first trimester, you move into the second trimester, then the third trimester.

How long is the first trimester?

The first trimester is three months long. It starts on the first day of your last period and goes up to the last day of the 12th week of your pregnancy.

Common first-trimester symptoms you can expect

In the first trimester of pregnancy, a lot of changes happen. Although each pregnancy is unique, many people experience similar symptoms that are caused by fluctuating hormones.

Common symptoms experienced during the first trimester include:

  • Bigger boobs: During the first trimester of pregnancy, it's common for your breasts to grow and become tender, This is caused by hormonal changes, especially an increase in progesterone levels. It's important to wear a comfy, well-fitting bra to support them and ease any discomfort.
  • Bloating and constipation: During the early stages of your pregnancy, you may experience constipation and bloating. Remembering to drink plenty of water and eating high-fibre foods can help.
  • Cravings or aversions: Many pregnant people crave certain foods or feel put off by foods and drinks that they used to like.
  • Discharge changes: Increased blood flow to the pelvic area can lead to an increase in cervical mucus and vaginal discharge that's commonly known as leukorrhea and is thin, milky, and white.
  • Fatigue and tiredness: Although your body may not change much on the outside during the first trimester, there's a lot of metabolic work going on inside to support the development of your baby, so it's common to feel tired. It's important to listen to your body and get plenty of rest.
  • Feeling the need to pee more, especially at night: Many pregnant people find that they need to pee more often than usual. This symptom can start during the first trimester.
  • Implantation bleeding or spotting: Light bleeding that resembles a light period is known as implantation bleeding and should only involve spotting or a small amount of blood loss. This is often experienced during the very early stages of pregnancy.
  • Missing a period: Missing a period is often the earliest sign of pregnancy if your menstrual cycle is regular.
  • Nausea or morning sickness: Morning sickness typically happens during the first trimester and unfortunately isn't restricted to just the morning - it can happen day and night. It's caused by hormonal changes and characterised by nausea and vomiting.

First-trimester pregnancy belly: Week by week

People don't usually start to notice a baby bump developing until around week 10 of their pregnancy.  

Some people can see a visible pregnancy bump by the end of their first trimester, while others can't. It just depends on your body and your baby's development, and it's so important to remember that each pregnancy is unique.

How your baby will develop during early pregnancy

A baby grows very quickly during the first trimester, and it's amazing how much they develop in just a few short months!

In the first trimester, the embryo transforms into a foetus, and major organs and body systems begin to form. By the end, the foetus is about the size of a peach with all their major organs and body systems in place. They'll continue to mature throughout the remaining two trimesters.

Signs your pregnancy is going well in the first trimester

Even though the symptoms you may encounter during your early pregnancy can be quite uncomfortable, a lot of the common ones we've discussed are completely normal. They can be considered good indications that your first trimester is progressing as it should.

However, it's also possible that you won't experience any of these typical first-trimester symptoms, and that's perfectly fine too. As long as your medical check-ups confirm that everything is going well, there's no need to be concerned.

Danger signs of pregnancy in the first trimester

It's important to be aware that certain symptoms can be warning signs during pregnancy. You should seek medical attention if you experience any of the following:

  • Fever: If you have a fever or high temperature above 37.5°C and are pregnant, you should seek medical attention.
  • Heavy bleeding: You should always speak to your doctor if you experience heavy bleeding from your vagina during pregnancy.
  • Itchy palms or feet: Experiencing slight itching during pregnancy around your belly or bump is normal, but feeling really itchy can sometimes be a sign of a condition called obstetric cholestasis or OC. If you have itchy palms and soles of your feet, you should speak to your doctor or midwife.
  • Mental health struggles: Don't hesitate to seek support if you're pregnant and feeling depressed, anxious or like you can't complete your usual, everyday tasks - especially if these feelings last for two weeks or longer. However you feel, you're not alone!
  • Skin rash: If you're pregnant and get any kind of rash, you should seek medical attention as soon as possible - especially if you've been around someone with shingles or chickenpox.
  • Abdominal pain: Stomach pain during pregnancy that's caused by trapped wind, constipation, or ligament pain is usually not cause for concern. But in some cases, abdominal pain can be a warning sign of something more serious. So, if you're pregnant and concerned about stomach pains, it's best to speak to get checked over by your doctor or midwife to put your mind at ease.
  • Extreme dizziness: If you're pregnant and often feel dizzy or become so dizzy that you faint, you should see your doctor. Dizziness or feeling faint can sometimes be caused by low iron levels or anaemia. This is a common side effect of pregnancy and can be treated by taking iron supplements prescribed by your doctor or midwife.

What you should do during your first trimester of pregnancy

  1. Go to all your antenatal appointments: These appointments are really important. They give your healthcare providers a chance to check on the health of you and your baby. During these appointments, you'll get lots of useful information and have the chance to ask any questions you have. Remember, there's no such thing as a silly question - especially during pregnancy!
  2. Take prenatal vitamins: All pregnant people in Australia are advised to take folic acid, iodine and vitamin D supplements.
  3. Get advice on taking medication during pregnancy: You should speak to your pharmacist or doctor to make sure any medication you're planning to take is safe to use during pregnancy. This includes any medicines prescribed by a doctor or purchased from a shop or pharmacy, including painkillers.
  4. Maintain a healthy diet: You can absolutely give in to your chocolate craving during pregnancy, but it's also important to stay hydrated and eat well to support your baby's growth and to keep yourself feeling energised and healthy.
  5. Keep exercising if you feel comfortable: Maintaining an active lifestyle during pregnancy is a great way to keep your energy levels up, improve your mood, and get ready for childbirth. It's completely safe for your unborn baby, and as long as you feel comfortable, you can engage in gentle exercise throughout your pregnancy, unless you've been advised otherwise by your healthcare provider.
  6. Advocate for yourself: If you have any concerns or questions about any aspect of your health, your pregnancy, or your baby's development, don't hesitate to speak to your healthcare provider for advice and support.

How many weeks is the first trimester?

There are 12 weeks in the first trimester.

We asked our Instagram followers what the first trimester felt like for them, and here's what they told us:

  • "I had zero symptoms apart from lack of period."
  • "Struggling with food aversions and sickness, while trying to act normal."
  • "The longest! Because you're keeping it quiet, but you want to explode and tell the world."
  • "Like I've got a little secret."
  • "Emotional and overwhelming."
  • "Mine was good, felt very hungry all the time."
  • "A real out of body experience, didn't feel like myself one bit."
  • "Tired and constantly feel sick but not being sick. Smells were triggering."
  • "Nausea, constantly hungry, always sleepy."

Many parents say that their first trimester was the most difficult. But because every pregnancy is different, it's not possible to pinpoint which week within the first 12 is the hardest. Remember to go easy on yourself and don't compare your unique pregnancy experience with anyone else's.