First Trimester
The first trimester is when your baby's major organs and body systems form. It's often the most physically challenging — morning sickness, fatigue, and rapid hormonal changes are common.
Baby Development Milestones
Common Symptoms
- Morning sickness / nausea
- Extreme fatigue
- Breast tenderness
- Food aversions or cravings
- Frequent urination
- Mood swings
- Bloating
- Heightened sense of smell
Prenatal Appointments
- First prenatal visit (8–10 weeks)
- Blood tests and urine tests
- Dating ultrasound
- NIPT or genetic screening (optional, 10–13 weeks)
- Nuchal translucency scan (11–14 weeks)
Quick Facts
- Duration: 13 weeks
- Weeks 1 through 13
- Months 1–4 of pregnancy
- Risk of miscarriage drops significantly at week 12
Tips for the First Trimester
- Start taking prenatal vitamins with folic acid
- Avoid alcohol, raw fish, high-mercury fish, and unpasteurized cheeses
- Stay hydrated — it helps with nausea
- Rest when you can; fatigue is intense and normal
- It's fine to wait until 12 weeks to share the news
Nutrition in the First Trimester
Early pregnancy nutrition is less about eating "for two" and more about consistency and covering key nutrient gaps, especially since nausea and food aversions are common in the first trimester and can make it hard to eat the way you planned to. If certain foods you used to enjoy suddenly feel unappealing, that’s a normal and common experience — the goal in these early weeks is simply to eat what you can tolerate while keeping your prenatal vitamin consistent, since that’s doing a lot of the nutritional heavy lifting when your actual food intake is inconsistent.
- Take your prenatal vitamin daily, ideally with food if it causes nausea, and ask your provider about switching brands or formulations if one isn’t sitting well.
- Small, frequent meals or snacks throughout the day can be easier to tolerate than three large meals, especially if nausea tends to strike on an empty stomach.
- Bland, carbohydrate-based foods (crackers, toast, rice) are often better tolerated during nausea-heavy stretches — it’s fine to lean on these temporarily.
- Stay hydrated, sipping fluids throughout the day rather than large amounts at once if nausea makes big glasses of water hard to manage.
- Avoid alcohol, raw or undercooked meat and eggs, unpasteurized dairy, and high-mercury fish throughout pregnancy, starting now.
- Don’t worry about calorie counts in the first trimester — actual calorie needs don’t meaningfully increase until later in pregnancy.
Staying Active in the First Trimester
If your provider has cleared you for exercise and you don’t have any pregnancy complications, most forms of moderate exercise you were already doing before pregnancy are generally safe to continue in the first trimester, though fatigue and nausea may naturally reduce your energy for it. Walking, swimming, and prenatal yoga are commonly recommended low-impact options if you’re starting fresh or scaling back from a more intense routine. It’s reasonable to listen to your body more than usual during this stage — if a workout that used to feel easy now feels exhausting, that’s a normal response to the hormonal and physical changes happening early in pregnancy, not a sign you need to push through it.
For Partners: Supporting the First Trimester
The first trimester can be physically and emotionally taxing in ways that aren’t always visible from the outside — nausea, fatigue, and mood shifts are common even when nothing looks different yet. Partners can help most in these early weeks by taking on more of the practical load (meals, errands, household tasks) without needing to be asked, checking in about how they’re actually feeling rather than assuming things are fine, and being patient with the unpredictability of symptoms like nausea and exhaustion that can vary significantly day to day.
Browse Week by Week
Frequently Asked Questions
This page gives you a broader overview of an entire trimester — common symptoms, appointments, and milestones spread across roughly 13 weeks — while the week-by-week guide breaks things down to a single week at a time with more specific detail. Many people use this page to get oriented to a new trimester, then switch to the week-by-week guide for closer tracking as their due date approaches.
The symptoms listed here reflect common patterns for this stage of pregnancy, not a complete or required list — plenty of people experience some of these symptoms earlier, later, more intensely, or not at all, and that's usually within the range of normal. If a specific symptom feels unusual or severe for your situation, it's always worth mentioning to your provider.
No — the milestones listed are general developmental patterns based on typical fetal growth, not measurements specific to your baby. Actual development varies within a normal range, and your provider tracks your baby's specific growth through your individual ultrasounds and appointments, which is a more precise way to monitor development than a general milestone list.
The appointments listed here reflect commonly recommended prenatal care for this stage, but your specific schedule may vary based on your provider, your health history, and whether your pregnancy is considered higher risk. Always follow the specific appointment schedule your provider recommends for you rather than treating this list as a strict requirement.
While many symptoms during any trimester are common and expected, sudden, severe, or unusual symptoms — such as heavy bleeding, severe abdominal pain, sudden swelling, vision changes, or a significant decrease in baby's movement — are always worth contacting your provider about promptly rather than waiting for your next scheduled visit.