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The Pregnancy Hub

13 weeks pregnant

Get to know your growing baby and the changes you may be feeling.

Choose your week

Week 13

Know your due date?

Enter the due date from your care team to find your estimated week today. Your date stays in this browser tab.

Illustration of a peach

Second trimester

About the size of

a peach

Approximate length

2.9 in / 7.4 cm Head to bottom

Your baby

Your baby is moving their arms and legs with increasing coordination. Thumb-sucking can help develop the sucking reflex used for feeding after birth. You may not feel these movements yet. The peach comparison is an approximate guide to length, not a target that your own baby has to match exactly this week.

Your body

As the uterus grows, your waistline and the way clothes fit may change. Some people feel more energetic, while nausea or fatigue continues for others. Activity does not need to look the same as it did before pregnancy. Pay attention to comfort and discuss new pain, dizziness or other symptoms rather than pushing through them to finish a workout.

This week

Staying active comfortably

Talk with your care team about the activities you already enjoy and any work that involves lifting, long periods on your feet or other physical demands. Ask whether your health or pregnancy calls for specific modifications. If activity is appropriate for you, a comfortable routine you can maintain is more useful than trying to compete with someone else's pregnancy. Consider small practical changes such as taking breaks, wearing comfortable shoes and choosing times when you feel well. Ask what symptoms should make you stop and seek advice.

Explore prenatal care

Looking ahead

A question for your next visit

Are my usual exercise and work activities appropriate, and what changes would help me stay comfortable?

Browse pregnancy weeks

A little context for these comparisons

These are approximate sizes for each week, not measurements of your baby. Babies and produce both come in different sizes, and the illustrations are not shown to scale.

Before week 20, length is measured from head to bottom. From week 20, it includes the legs, from head to heel. That change explains the jump in length between weeks 19 and 20.

When to get help

Seek medical care right away for warning signs such as a severe or persistent headache, vision changes, chest pain, trouble breathing, severe belly pain, vaginal bleeding, leaking fluid, or thoughts of harming yourself or your baby. These are examples, not a complete list. If you cannot reach your care team, seek urgent medical care. Call 911 for a medical emergency.

Read the CDC urgent maternal warning signs (opens in a new tab)
About this guide

Approximate measurements and development information draw on the NHS weekly guides. Linked US health resources support care and preparation topics. The topics are suggestions for discussion, not a schedule of required appointments or tests. Your own care plan may differ.

Every pregnancy is different. Your care team can help you understand your baby’s growth and any symptoms you’re experiencing.