Twenty-four weeks of pregnancy is the end of the sixth month and the final stretch of the second trimester. At this point, your baby is roughly 8¼ inches long from crown to rump and weighs about 1⅓ pounds (630 grams). This week is also a significant medical milestone: it marks what doctors consider the threshold of viability, meaning a baby born at 24 weeks has a realistic chance of surviving outside the womb with intensive care.
How 24 Weeks Translates to Months
Pregnancy math is confusing because calendar months don’t divide evenly into weeks. A full-term pregnancy lasts about 40 weeks, split into three trimesters. At 24 weeks, you’re wrapping up month six and sitting near the tail end of the second trimester, which runs from week 13 through week 27. The third trimester begins at week 28.
What Your Baby Looks Like at 24 Weeks
At this stage, your baby’s features are becoming more defined. The skin is still thin and somewhat translucent, covered in fine, downy hair called lanugo that helps regulate body temperature. Eyelids have formed but remain fused shut for a few more weeks. Fingerprints and footprints are developing, and the face looks more proportional as fat slowly begins to fill in beneath the skin.
Brain development is accelerating rapidly. Starting around 24 weeks, nerve fibers from deep brain structures begin making their first electrical connections with the outer layer of the brain, the cortex. These early connections are the foundation for processing sensory information. Your baby can now hear sounds from outside the womb and may startle in response to loud noises. Taste buds are also functional, and swallowing amniotic fluid exposes the baby to different flavors from your diet.
Why 24 Weeks Is the Viability Threshold
If a baby is born at 24 completed weeks of gestation, the survival rate is approximately 72%, based on a large U.S. national database covering over a decade of births. That number has been climbing steadily, rising from about 68% in 2007 to roughly 73% by 2018. For context, babies born even slightly earlier, before reaching 24 weeks, have a survival rate of only about 15%.
That dramatic jump in survival is why 24 weeks is treated as a critical dividing line. At this gestational age, the lungs have developed enough tiny air sacs to potentially exchange oxygen with medical support, and the brain’s wiring has progressed enough to coordinate basic body functions. Hospitals with neonatal intensive care units will typically provide full resuscitation efforts for a baby born at 24 weeks, whereas the approach for earlier deliveries varies more widely depending on the circumstances.
Survival does not mean a baby escapes the NICU quickly or without complications. Premature infants born this early face risks including brain bleeds, intestinal problems, and long-term developmental challenges. The stay in intensive care often lasts months. Still, advances in neonatal medicine have made outcomes at 24 weeks far better than they were a generation ago.
What You Might Be Feeling
By 24 weeks, many of the uncomfortable first-trimester symptoms like nausea have faded, but a new set of physical changes takes their place.
- Braxton Hicks contractions. These are mild, irregular tightenings of your belly that come and go. They tend to show up in the afternoon or evening, especially after physical activity or sex. They’re not a sign of labor, but staying hydrated and emptying your bladder regularly can reduce how often they happen.
- Leg cramps. Cramping in the calves becomes more common around this time, particularly at night. Stretching your calf muscles before bed, staying active during the day, and drinking plenty of water can help. If a cramp hits, flexing your foot upward (toes toward your shin) usually releases it.
- Skin changes. Rising hormone levels increase melanin production, which can cause brown or gray patches on your face (sometimes called the “mask of pregnancy”) and a dark vertical line down the center of your belly known as the linea nigra. Both typically fade after delivery.
Your belly is noticeably larger now, and you’re likely feeling regular, recognizable kicks and rolls rather than the subtle flutters of earlier weeks. Many providers suggest starting to pay attention to fetal movement patterns around this time.
Glucose Screening Happens Around Now
Between 24 and 28 weeks, your provider will schedule a glucose screening test to check for gestational diabetes. The test involves drinking a sugary liquid and having your blood drawn about an hour later to measure how your body processes the sugar. You don’t need to fast beforehand. If your blood sugar comes back above a certain threshold, you’ll be asked to take a longer, more detailed glucose tolerance test to confirm or rule out the diagnosis. Gestational diabetes is common and manageable, but catching it early matters for both your health and the baby’s growth.
What Happens if Preterm Labor Starts at 24 Weeks
Because 24 weeks sits right at the edge of viability, any signs of preterm labor at this stage are treated urgently. If delivery looks likely, the medical team’s priorities shift to buying time and protecting the baby’s development. You would receive steroid injections to help speed up lung maturation, along with medication to protect the baby’s brain. Doctors may also use medications to slow or stop contractions, and antibiotics if your water has broken early.
Ideally, a birth this early happens at a hospital equipped with a high-level NICU. If you’re at a smaller facility, a transfer to a regional medical center is the typical recommendation when time allows. Every additional day the baby stays in the womb at this stage meaningfully improves the odds.