At 24 weeks pregnant, your baby weighs just over 1⅓ pounds (630 grams) and measures about 8¼ inches from crown to rump. This week marks a significant medical milestone: viability. It’s also when routine screening for gestational diabetes typically begins, making it one of the busiest checkpoints in your second trimester.
How Your Baby Is Developing
Your baby’s skin is reddish, wrinkled, and still translucent enough that veins are visible through it. That see-through quality won’t fully disappear until around week 32, as layers of fat gradually build underneath. Right now, the baby is gaining weight steadily, and the face is nearly fully formed.
The eyelids are beginning to part during month six, though true blinking won’t happen for a few more weeks. The lungs are developing rapidly but aren’t yet producing surfactant, the coating that allows air sacs to inflate after birth. That production kicks in closer to week 26. In the meantime, the baby is practicing breathing motions by inhaling and exhaling small amounts of amniotic fluid, which helps the lungs mature.
Your baby’s hearing is increasingly sharp. Familiar sounds like your voice and heartbeat are becoming recognizable. You may notice the baby reacting to loud noises or music with a kick or shift in position.
Why Week 24 Is a Viability Milestone
Week 24 is widely recognized as the threshold of viability, the point at which a baby born prematurely has a meaningful chance of survival with intensive medical care. According to the American College of Obstetricians and Gynecologists, survival rates for infants born at 24 weeks range from 42% to 59%. That’s a significant jump from 23 weeks (23% to 27%) and climbs further at 25 weeks (67% to 76%). Every additional day in the womb at this stage meaningfully improves outcomes.
This doesn’t mean you need to worry about preterm birth. It simply means that if complications did arise, your medical team now has more options. Most pregnancies continue well past this point without incident.
The Glucose Screening Test
Between weeks 24 and 28, you’ll be offered a glucose challenge test to screen for gestational diabetes. This is one of the most common prenatal tests, and it’s straightforward.
You’ll drink a sweet syrup containing about 50 grams of sugar. Then you wait one hour without eating or drinking anything other than water. After that hour, a blood sample is drawn from your arm. If your blood sugar comes back below 140 mg/dL, no further testing is needed. If it falls between 140 and 190 mg/dL, you’ll be asked to return for a longer, three-hour glucose tolerance test to confirm or rule out gestational diabetes. Some clinics use a lower cutoff of 130 mg/dL, so don’t be alarmed if your provider flags a result that seems borderline.
Gestational diabetes is manageable when caught early, usually through dietary changes, blood sugar monitoring, and sometimes medication. The screening exists to catch it before it causes problems for you or your baby.
What Your Body Feels Like
Your uterus is now roughly the size of a soccer ball, and the shift in your center of gravity is becoming more noticeable. You may find yourself adjusting your posture or feeling less steady on your feet than usual. Back pain is common as your body compensates for the extra weight up front.
Braxton Hicks contractions can start appearing around this time. These feel like a mild tightening across your belly that comes and goes, almost like your uterus is doing a practice squeeze. They tend to show up in the afternoon or evening, after physical activity, or after sex. They’re irregular, short-lived, and not painful in the way real labor contractions are.
Swelling in your hands, feet, and ankles is increasingly common as your blood volume continues to rise. Hormonal changes can also cause the lining of your nose to swell, leading to congestion or nosebleeds that seem to come out of nowhere. Leg cramps, especially at night, and trouble finding a comfortable sleeping position are par for the course at this stage.
Signs of Preterm Labor to Watch For
While Braxton Hicks are normal, it’s important to know the difference between practice contractions and something that needs medical attention. Preterm labor symptoms include:
- Contractions every 10 minutes or more often, or six or more tightenings in a single hour
- A change in vaginal discharge, including leaking fluid or any bleeding
- Pelvic pressure that feels heavy or different from usual
- A low, dull backache that doesn’t go away with rest or position changes
- Cramping similar to menstrual cramps, with or without diarrhea
If you experience any combination of these, especially frequent contractions or fluid leaking from the vagina, call your provider or go to the hospital for evaluation. Early intervention can often slow or stop preterm labor.
Planning and Practical Steps
With roughly 16 weeks to go, this is a good time to start thinking about logistics without feeling rushed. You don’t need a fully decorated nursery yet, but focusing on essentials like a safe sleep space, a car seat, and basic supplies keeps you from scrambling later.
Many people begin drafting a birth plan around now. This is simply a document outlining your preferences for labor and delivery: who you want in the room, how you feel about pain management, and any specific requests for after the baby arrives. There’s no single correct format. Think of it as a way to communicate your best-case scenario to your care team, knowing that flexibility will be part of the process.
It’s also worth sorting out practical details you might overlook later. How will you get to the hospital or birth center when the time comes? If you have other children or pets, who handles them while you’re away? Locking in these plans now takes one more thing off your plate during the final stretch.
Rh Factor and Blood Type
If your blood type is Rh-negative and your baby’s father is Rh-positive, your provider will schedule an injection between weeks 26 and 28 to prevent your immune system from producing antibodies against the baby’s blood cells. This is a routine precaution, not a sign that anything is wrong. If this applies to you, expect your provider to bring it up at an upcoming appointment.