What to Expect in Each Trimester: A Week-by-Week Breakdown

Pregnancy is a journey filled with constant change—for both you and your baby. Understanding what happens week by week can help you stay prepared, calm, and confident. This guide walks you through body changes, baby development, key medical milestones, and what to wear as your shape evolves.

First Trimester (Weeks 1–12)

Body Changes

Fatigue, nausea, breast tenderness, bloating, and heightened emotions are the most common experiences. Hormones shift dramatically, and your body begins preparing for placenta development. Many moms also notice more frequent urination and food aversions.

Baby Development

• Week 5: Heartbeat begins.

• Week 6–7: Facial features start forming.

• Week 8–10: Major organs develop and baby moves (even though you can’t feel it yet).

• Week 11–12: Baby reaches about 2 inches long, and fingers/toes are formed.

Health Check Guidelines

Your first prenatal appointment usually happens between weeks 8–10. Doctors confirm the pregnancy, assess due date, run bloodwork, and discuss general health, medications, and lifestyle. If you’re considered higher-risk, you might have additional early tests.

Clothing Needs Timeline

Most women can still wear regular clothes, but comfort becomes increasingly important. Light stretch, soft waistbands, and breathable tops make early symptoms easier to manage.

Cozymomstyle picks for this stage: early-bump leggings, seamless tops, and soft lounge basics.

Second Trimester (Weeks 13–27)

Body Changes

Energy usually returns, and nausea eases for many moms. Your bump becomes more visible, and you may experience increased appetite, round ligament pain, and occasional swelling. This is also when many women start feeling baby movements.

Baby Development

• Week 14–16: Baby can make facial expressions.

• Week 18–20: Anatomy scan shows major organs—and you may learn the sex.

• Week 21–24: Baby hears sounds and practices swallowing.

• Week 25–27: Baby develops sleep cycles and gains fat.

Health Check Guidelines

You’ll have monthly prenatal visits. Around week 20, you get a detailed ultrasound (anatomy scan). Around weeks 24–28, you’ll take the glucose test to check for gestational diabetes.

Clothing Needs Timeline

This is the growth phase—your belly expands quickly, and maternity clothing becomes essential. Look for stretchy bottoms, bump-friendly dresses, and tops with flexible cuts.

Cozymomstyle picks for this stage: maternity leggings, soft-stretch dresses, athleisure sets.