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23 Weeks Pregnant: Baby Size, Symptoms and What to Do

Week 23 is in the second trimester, month 6 of pregnancy. Here's how big your baby is, what's developing, what you may feel and what to do this week.

Week 23 · 2nd trimester · month 6
About the size of a zucchini
about 11.4 in (29 cm) · 1.2 lb (565 g) (head to heel)

Your baby this week

Your baby's arms and legs are now in proportion with the body. Sometimes you can even see movements ripple across your belly.

At 23 weeks your baby's skin is still wrinkly because fat is only now building up quickly. Branches of the airways and tiny air sacs are developing in the lungs, ready for gas exchange later. Your baby may move in response to sounds. This is a good time to get to know your baby's pattern of movement: when they're more active and when they rest. There's no set number that applies to every baby, so your baby's own pattern is what counts. If movements slow down, change or stop, call labor and delivery right away, even at night, rather than waiting. The window for glucose screening, usually 24 to 28 weeks, is coming up, so check when yours is scheduled.

By the numbers

Week 23 covers days 161 to 167 counted from the first day of your last period, which is 57% of a 40-week pregnancy. About 119 days remain until a 40-week due date. Since last week, an average baby gains about 3.1 oz (89 g). By date of conception, your baby is about 21 weeks old.

Pregnancy is dated from the first day of your last period, so conception happens around week 2. Your due date is 280 days (40 weeks) from that day, and an early ultrasound may adjust it.

Your body

Get to know your baby's usual pattern of movement. If movements slow down, change or stop, call your provider or labor and delivery right away instead of waiting until the next day.

Tests and to-dos this week

Start thinking about a pediatrician; many practices offer prenatal meet-and-greet visits.

No routine test falls in this exact week; your provider schedules your regular checkups.

Coming up: Glucose screening for gestational diabetes (from week 24). Full prenatal visit schedule

Tips for the second trimester

  • Most healthy pregnant people are advised to get about 150 minutes of moderate activity a week, such as walking or swimming.
  • Your recommended weight gain depends on your pre-pregnancy BMI, and gain usually speeds up in the second trimester.
  • Once you feel your baby regularly, learn their usual pattern; a change in pattern matters more than any count.
  • The flu shot is recommended at any point in pregnancy during flu season.

Call your provider or labor and delivery right away if you have:

  • vaginal bleeding or leaking fluid
  • regular contractions or pelvic pressure before 37 weeks
  • a severe headache, vision changes, or sudden swelling of the face or hands
  • a fever of 100.4 °F (38 °C) or higher, or painful urination
  • after 24 weeks, your baby moving less or differently

In an emergency, call 911.

Last week and next week

Last week (22): The lungs are developing, and your baby practices breathing movements.

Next week (24): The lungs keep maturing.

Frequently asked questions

How big is the baby at 23 weeks?

About the size of a zucchini: about 11.4 in (29 cm) · 1.2 lb (565 g), measured head to heel. These are rounded averages, and every baby grows at their own pace.

How many months is 23 weeks pregnant?

23 weeks is in month 6 and the second trimester. About 17 weeks (119 days) remain until a 40-week due date. Months are approximate; providers count weeks and days.

How many times should the baby move a day?

There's no number that fits every baby. Guidance is to learn your own baby's usual pattern; if movements slow down or change, call labor and delivery right away.

What's the next test or appointment after week 23?

Next up: Glucose screening for gestational diabetes, from week 24. Your provider may schedule things differently depending on your health and local practice.

Sources

Last reviewed: November 14, 2026 · Kitpebble editorial team

This page is for general information. It isn't medical advice or a diagnosis and doesn't replace your OB-GYN or midwife. Sizes are rounded averages. Our editorial policy

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