Pregnancy Week 24: Your Baby Can Hear You — and a Key Medical Milestone

24 weeks — the viability threshold Your baby hears you clearly now, and has a survival chance if born early

Week 24 is a significant medical milestone. It marks the viability threshold — if a premature birth were to happen now, your baby has a chance of survival with NICU care, even though the risks and potential complications remain high.

It's also the key window for gestational diabetes screening (GDM), per guidance from ACOG [1], WHO [2], and the Royal Thai College of Obstetricians and Gynaecologists [3].

Your baby at week 24

Your baby is about 30 centimeters long and weighs approximately 600 grams — roughly the size of a large ear of corn.

Key developments this week:

• Lungs are beginning to produce surfactant — the substance that keeps the air sacs from collapsing at birth. Production isn't sufficient until around week 34, but it has started
• Brain is developing rapidly and the first folds (gyri) are forming on the surface
• Ears are fully functional — your baby can hear your voice, their father's voice, music, and the internal sounds of your body (your heartbeat, your digestive system)
• Response to light is emerging — blinking and squinting if a bright light shines on your abdomen
• Sleep-wake cycles are establishing — rhythmic patterns you may start to notice
• Skin is still thin and wrinkled, but fat is beginning to accumulate beneath it
• Fingerprints and toe prints are fully formed
• Sex is clear — genitalia are developed in most cases

What "viability" at 24 weeks actually means

According to ACOG [1] and AAP [4]:

Survival rates by gestational age

• 22 weeks: approximately 10–30% — very low survival
• 24 weeks: approximately 50–70% — the viability threshold
• 26 weeks: approximately 80–90%
• 28 weeks: approximately 90%+ — most survive, but complications remain a risk

Complications associated with birth before 28 weeks

• Respiratory Distress Syndrome — lungs not yet fully developed
• Intraventricular Hemorrhage — bleeding in the brain
• Necrotizing Enterocolitis — intestinal inflammation
• Retinopathy of Prematurity — vision problems
• Long-term developmental delays

A baby born at this stage would need to spend several months in the NICU.

Signs of preterm labor — go to hospital immediately

• Rhythmic uterine contractions — more than 4 in one hour
• Rhythmic low back pain or lower abdominal pain
• Any vaginal bleeding
• Fluid leaking from the vagina
• Brown or pink discharge from the vagina
• Unusual pelvic pressure

Gestational Diabetes (GDM) Screening

ACOG [1] and the Royal Thai College of Obstetricians and Gynaecologists [3] both recommend screening at 24–28 weeks.

The test: 75g Oral Glucose Tolerance Test (OGTT)

• Fast for at least 8 hours (water is fine)
• First blood draw for fasting glucose
• Drink 75 g of glucose solution
• Blood draws at 1 hour and 2 hours after drinking

Diagnostic thresholds — GDM is diagnosed if any one value is met or exceeded:

• Fasting: ≥ 92 mg/dL
• 1 hour: ≥ 180 mg/dL
• 2 hours: ≥ 153 mg/dL

If you're diagnosed with GDM

• Adjust your diet — reduce refined carbohydrates, increase vegetables and protein
• Light exercise — 30 minutes, 5 days/week
• Monitor blood glucose 4 times/day with a finger-stick test
• Medication (insulin or oral agents) if lifestyle changes aren't enough — your doctor will guide you

Well-managed GDM generally has little impact on the baby. Uncontrolled GDM increases risk of macrosomia (a very large baby), low blood sugar in the newborn, difficult delivery, and a higher lifetime risk of type 2 diabetes for the mother.

Self-care at week 24

Kick counting

Per ACOG [5]:

• Start counting from 24–28 weeks
• Choose a time when your baby tends to be active (often after meals)
• Goal: 10 movements in 2 hours is normal
• If fewer than 10, have something sweet and try again
• If still fewer than 10, contact your provider right away

Sleep

• Sleep on your left side — improves blood flow to your baby
• Avoid lying flat on your back for long periods — the uterus can compress the vena cava
• Use a pregnancy pillow to support your belly and back

Nutrition

• Fiber — more vegetables and fruit to ease worsening constipation
• Water — at least 10 glasses/day
• Iron-rich foods — to prevent anemia
• Reduce refined sugars and sweets — especially while preparing for the OGTT

Activity

• Keep exercising — reduce intensity as your body asks
• Childbirth preparation classes — most hospitals offer them from weeks 24–28, a great time to enroll
• Talk and sing to your baby — they can hear and are starting to recognize voices

When to seek care immediately

• Signs of preterm labor — contractions, back pain, bleeding, fluid leaking
• Reduced fetal movement after you start counting
• Severe headache, swelling, or blurred vision — pre-eclampsia
• Severe vomiting — unusual in the second trimester
• Pain when urinating — possible UTI
• Fever above 38.5°C (101.3°F)

Summary

Week 24 is a turning point — medically (viability + diabetes screening) and emotionally (your baby can hear you).

Care principles for this week:

1. Prepare for the OGTT at 24–28 weeks
2. Start kick counting daily — 10 movements in 2 hours
3. Sleep on your left side as a regular habit
4. Talk and sing to your baby — building a bond before birth
5. Enroll in a childbirth preparation class at your hospital
6. Know the signs of preterm labor — at this week, your baby has a chance of survival, but every additional week in the womb matters enormously

Every day your baby spends inside is a gift — survival odds and long-term quality of life improve with each passing week.