What the first trimester actually is

The first trimester runs from week 1 through week 13, counted from the first day of your last period. It can be a strangely private stretch of time. Often, there’s no bump or movement. The main evidence can be fatigue and nausea. You may have to manage these changes while the world around you sees nothing different.

This is also a period of rapid development for your baby. During the first trimester, major organs and body systems begin to form, the heart starts beating and the foundations for growth throughout the rest of pregnancy are established. By the end of the trimester, your baby has developed recognizable arms, legs, fingers and toes, even though they are still very small.

It's also worth saying plainly: most pregnancy loss occurs in the first trimester. Miscarriage affects roughly one in 10 known pregnancies, so an honest "what to expect" discussion includes some uncertainty. Worry can be a common part of the first-trimester experience.

Why this may be harder than people expect

Many people wait until around 12 weeks to share the news. That can mean carrying nausea, excitement, exhaustion and worry privately, often while working and trying to show up in life as usual. Some people might share their pregnancy news with their loved ones and don’t get the happy reactions they were hoping for. It might take some time for people to adjust to the news, and that can make this experience even more complex, when some people do not share your joy.

You may also be contemplating the long road ahead — birth, becoming a parent and possibly grieving a version of your life you're leaving behind. It’s common to ask yourself, “How am I going to do this?” [1]

Even if you do have someone to share your news with, it can be hard to convey these complex feelings. In other words, the first trimester can feel lonely, even when you're surrounded by people who love you. If that resonates, it's worth knowing the feeling is very common.

Your body in the first trimester

A lot changes physically, and most of it is driven by the hormonal shifts of early pregnancy. Common experiences include:

• Nausea, sometimes with vomiting: often called "morning sickness," though it can arrive at any time of day and affects a lot of pregnant people

• Deep fatigue: he kind that isn't fixed by a good night's sleep

• Tender or swollen breasts, bloating and changes in appetite

• Taste aversions and a sharper sense of smell: Foods/tastes you used to like can suddenly turn your stomach, and scents that never bothered you before are suddenly all you can smell and make you nauseous

Other common symptoms can include frequent urination, headaches, constipation, mild cramping, dizziness or spotting. Many of these changes are linked to pregnancy hormones and increased blood flow. While they can be uncomfortable, they’re often a normal part of early pregnancy, though persistent or severe symptoms should be discussed with a provider.

On the other hand, some people don’t notice any pregnancy symptoms in the first trimester at all. This can be surprising but doesn’t reflect on the health of the pregnancy.

First-trimester pregnancy symptoms can be tough, especially when you may be trying to hide them. Not feeling well physically makes everything harder, including paying attention to your mental health.

Read more about “Dos & don’ts” for the first trimester [2]

Your mental health matters just as much

Physical symptoms tend to get the most attention in early pregnancy. Your emotional health deserves just as much attention.

Some weepiness and mood shifts in early pregnancy are common and expected. What's worth paying closer attention to is a low mood that doesn't lift, a loss of interest in things you'd normally care about, or anxiety that stays with you. If you’re experiencing any of these over a longer period of time, it’s worth a conversation with a care provider. There's a spectrum of mental health challenges that can start during pregnancy, not only after birth — including depression, anxiety, OCD and others (often referred to as perinatal mood and anxiety disorders or PMADs). There's rarely a single cause; a mix of physical, emotional and social factors plays a part. About one in four birthing parents in Canada report a mood concern across the perinatal period.

For partners and non-birthing parents

Mental health challenges don't only affect the person who is pregnant. If you're the partner to someone who is pregnant, you may be watching someone you love go through a major life change. One concrete thing you can do this week is ask your partner an open-ended question, like “How are you really doing with all of this?”

If your partner is coping well but you’re having trouble, that’s worth acknowledging. Non-birthing parents can also have emotional and mental health issues during this time and deserve to be supported. You may want to start by speaking with your partner to let them know how you’re feeling and reach out to other trusted supporters in your life. If you continue to have difficulty, you may want to seek our more formal support.

Where to start if you don't have a provider yet

Not everyone begins pregnancy with a doctor or other care provider. If that's you, you're not behind — you just need a starting point.

Whatever you're feeling right now — excited, anxious, numb, or some mix you can't quite name — it makes sense given everything that's shifting. If anything here rings true, write down one question to ask at your next appointment. Our Service Finder can help you find someone to see and how to begin.

Read more about Medical care: Who to see and what to expect [3]

If something here feels significant, write down one question to ask at your next appointment. Our Service Finder so help you figure out who to see and when.

This article was developed using sourced educational content from Canadian Perinatal Mental Health Trainings CPMHT, and informed by the collective knowledge and expertise of CPMHT professionals and Karen Clarke, BA, MSW, RSW, Doula Open Book Doula, Counselling and Consulting Services, as well as the following cited research and clinical practice guidelines: