24 Weeks Pregnant
At 24 weeks pregnant your baby reaches the viability milestone, the point at which survival outside the womb becomes possible with intensive newborn care. Your baby is about the size of an ear of corn, roughly 12 inches long and close to a pound and a half to two pounds. Glucose screening for gestational diabetes is coming up over the next few weeks, and your fundal height now starts to track your number of weeks.
Ear-of-corn-sized and crossing a real milestone — the lungs are starting to make surfactant, the substance that lets air sacs open after birth.
30.0 cm length · ~600 g weight
Your week at a glance
| This week | Details |
|---|---|
| Baby size | About an ear of corn, roughly 12 inches long, close to 1.5 to 2 pounds |
| What is developing | Lungs begin making surfactant, eyebrows and lashes formed, eyes nearly ready to open |
| Your symptoms | Stronger kicks, Braxton Hicks, back ache, swelling, occasional heartburn |
| To-do | Plan your glucose screen, keep noting movement, watch for preterm-labor signs |
The viability milestone
Around 24 weeks is widely treated as the threshold of viability. A baby born now has a real chance of survival with neonatal intensive care, though the risk of complications is high. Each additional week in the womb improves the odds significantly, which is why providers work hard to prevent preterm birth.
A big reason this week matters is the lungs. Specialized cells start producing surfactant, the substance that keeps tiny air sacs from collapsing, around 24 to 28 weeks. Mature lungs are usually not reached until about 34 to 36 weeks, so any tightening or leaking before 37 weeks deserves a call to your provider.
Fundal height starts to track your weeks
From about 24 weeks, the distance from your pubic bone to the top of your uterus, measured in centimeters, usually matches the number of weeks you are pregnant, give or take roughly 3 centimeters. At 24 weeks that is about 24 centimeters, and at 27 weeks about 27 centimeters.
This quick tape-measure check helps your provider follow growth between ultrasounds. A measurement that is well outside the expected range may prompt a growth scan, but a small difference on its own is common and usually not a concern.
Glucose screening is coming up
Most people are screened for gestational diabetes between 24 and 28 weeks.
- You drink a sweet glucose solution, usually 50 grams, with no fasting needed
- Blood is drawn one hour later to check your level
- A result of about 130 to 140 mg/dL or higher leads to a longer follow-up test
- The follow-up is a fasting 3-hour test using 100 grams of glucose with four blood draws
- Two or more high values on that test mean gestational diabetes, which is manageable with your care team
Common symptoms this week
- Stronger, more regular kicks as the baby gets bigger
- Braxton Hicks, occasional painless tightenings of the uterus
- Back ache and pressure as your bump grows
- Mild swelling in the feet and ankles
- Heartburn or indigestion after meals
What the baby is doing now
The baby's face is nearly complete, with eyebrows and eyelashes formed, and the eyes are developed even though they tend to stay closed for another couple of weeks. The inner ear is working, so the baby can hear muffled sounds, including your voice and heartbeat.
Skin is still thin and reddish because fat is only starting to build up underneath. Over the third trimester that fat will fill out the baby's frame and help with warmth and energy after birth. For now the baby is steadily lengthening and gaining weight week by week.
Call your provider if
- Regular tightenings, pelvic pressure, or low back pain that comes in waves before 37 weeks
- Any vaginal bleeding or a leak or gush of fluid
- A clear drop in how much the baby is moving
- Severe headache, vision changes, or sudden swelling of the face and hands
- Burning with urination, fever, or chills
Reflects ACOG gestational-diabetes screening guidance and Mayo Clinic and Cleveland Clinic references, 2024-2026.
Related questions
- What does viability at 24 weeks mean?
- It means a baby born at this stage can sometimes survive with intensive newborn care. The risk of serious complications is still high at 24 weeks, and survival and healthy outcomes improve a lot with each additional week, so the goal is always to keep the pregnancy going as long as it is safe to do so.
- When is the glucose test in pregnancy?
- The screening glucose challenge is usually done between 24 and 28 weeks. It is a one-hour test after a sweet drink, with no fasting needed. If your level is above the cutoff, your provider will order a longer fasting test to confirm or rule out gestational diabetes.
- Is 24 cm fundal height normal at 24 weeks?
- Yes. After about 24 weeks, fundal height in centimeters usually matches your weeks of pregnancy within roughly 3 centimeters, so around 24 cm at 24 weeks is expected. Your provider uses this trend along with ultrasounds to follow growth.
- How big is the baby at 24 weeks?
- Roughly 12 inches long and about a pound and a half to two pounds, often compared to an ear of corn. Babies vary in size, so numbers a little above or below average are still normal.
Sources & further reading
ParentFlow: one free app, newborn to age six
ParentFlow is a free baby tracker that logs feeds, sleep, diapers, pumping and growth in one tap, with your daily summary, trends, and reminders based on your own logs. Free for everyday tracking on iPhone, Android, and the web.
App Store Google Play Open Web AppThis article reflects current AAP, CDC, FDA, and other public-health guidance and is for educational purposes only. It does not constitute medical advice. ParentFlow is a wellness companion — not a substitute for your pediatrician. For any medical concern, contact your healthcare provider.