GUIDE
This is the viability milestone — your baby now has a fighting chance of survival if born prematurely, with intensive medical care.
At the size of an ear of corn, your baby's lungs are developing rapidly, and the glucose screening test is typically done around now.
Be prepared from day one
Your baby is about the size of an ear of corn — roughly 12 inches long and weighing around 1.3 pounds. This week marks one of the most significant milestones in pregnancy: viability.
Viability means that if your baby were born now, they would have a chance of surviving with intensive neonatal care. At 24 weeks, survival rates are roughly 40-70%, depending on the medical facility and individual factors. This is a testament to how far your baby has developed — but every additional week in the womb dramatically improves outcomes. At 28 weeks, survival rates climb to over 90%.
The lungs continue their critical development. Surfactant production is increasing, and the branching structure of the airways is becoming more complex. The lungs are still too immature to function independently, but the foundation is being built. Your baby continues to practice breathing by inhaling and exhaling amniotic fluid.
Your baby's face is nearly fully formed and is becoming more expressive. They can furrow their brow, squint, and make sucking motions. The inner ear is now fully developed, which means your baby has a sense of balance and can tell when they are upside down — though at this stage, they flip and turn frequently.
Since last week, hearing has further refined, and your baby may respond to familiar sounds and voices with movement.
Your uterus is now about the size of a soccer ball and extends well above your belly button. The rapid growth of the past few weeks is evident in how you feel — back pain, swelling, and sleep disruptions are all increasing.
Swollen feet and ankles are one of the most common complaints at 24 weeks. Your body is retaining more fluid than at any other point in your life, and your growing uterus is putting pressure on the major veins that return blood from your lower body. Mild to moderate swelling is normal. Sudden, severe swelling — especially in your face and hands — can be a sign of preeclampsia and should be reported to your provider immediately.
The glucose screening test is typically performed between 24 and 28 weeks. Gestational diabetes affects about 6-9% of pregnancies and occurs when pregnancy hormones interfere with your body's ability to use insulin effectively. If diagnosed, it is usually manageable with dietary changes and monitoring — and sometimes medication. Early detection is key.
You may also notice tingling or numbness in your hands and wrists, especially at night. Pregnancy-related carpal tunnel syndrome is caused by fluid retention putting pressure on the nerves in your wrists. Wearing a wrist splint at night and shaking your hands out when they feel numb can provide relief. It usually resolves after delivery.
Heartburn may be worsening as your uterus continues to push your stomach upward. Eating smaller meals, avoiding lying down right after eating, and talking to your provider about safe antacids can help.
Every pregnancy is different. The viability milestone is a great time to check in with your provider about any symptoms that are affecting your quality of life.
This is a milestone week — the glucose test, viability, and increasing preparation for the third trimester make it a busy one.
Your provider will likely schedule the glucose challenge test between 24-28 weeks. You will drink a sugary solution and have your blood drawn one hour later. It is a quick test, and most women pass without issue. If your levels are elevated, a follow-up three-hour test will determine if you have gestational diabetes.
Now that you have reached viability, it is important to know what preterm labor looks like: regular contractions, pelvic pressure, lower back pain that comes and goes, vaginal bleeding or fluid leaking, or a change in vaginal discharge. If you experience any of these, call your provider immediately.
Make it a habit to put your feet up for 15-30 minutes at least once a day. This helps reduce the swelling that comes with increased fluid retention and the pressure of your uterus on your pelvic veins. Lying on your left side is the most effective position for improving circulation.
A birth plan does not need to be rigid, but thinking through your preferences — pain management, labor positions, who you want in the room, preferences for immediate postpartum care — helps you feel more prepared. Discuss your thoughts with your provider at your next appointment.
When in doubt, call your provider. Knowing the signs of preterm labor is especially important now that your baby has reached viability.
At 25 weeks, your baby will be the size of a cauliflower and will start responding to familiar voices. Fat deposits are increasing, and the startle reflex is present.
The glucose test may be scheduled this week or in the coming weeks. And if pregnancy insomnia is becoming an issue, you are not alone — sleep disruptions tend to increase from here on out.
This guide is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider with any questions about your pregnancy.
