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The Pregnancy Hub

18 weeks pregnant

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

Choose your week

Week 18

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 bell pepper

Second trimester

About the size of

a bell pepper

Approximate length

5.6 in / 14.2 cm Head to bottom

Your baby

Hearing, swallowing and sucking abilities continue developing while your baby moves their arms and legs. Movements are happening before every pregnant person can recognize them. Early sensations may be subtle, so the week you first notice movement can differ from someone else's, especially in a first pregnancy.

Your body

You might feel a flutter, bubbling or a light shifting sensation, or you may not be sure whether you have felt anything yet. Your growing bump can also affect balance and comfort. Avoid using this guide or another person's experience as a deadline for a particular sensation. Ask your clinician what to expect in your circumstances and when to contact them if you remain unsure.

This week

Getting to know early movements

Use the next visit to ask how you will learn your baby's movement pattern as pregnancy progresses. There is a difference between not yet recognizing early movement and noticing a reduction after a usual pattern has developed. If movements you normally feel slow down, stop or change, contact your maternity care team right away rather than waiting for a scheduled visit. You can also ask about your upcoming anatomy ultrasound and how to prepare. A scan and your own awareness of movement answer different questions about the pregnancy.

Explore prenatal care

Looking ahead

A question for your next visit

What should I expect as movements become clearer, and when should I contact you about a concern?

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

If your baby’s usual movements slow down, stop, or change, contact your maternity care team right away.

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.