At 24 weeks pregnant, your baby is roughly 12 inches (30 cm) long from head to heel and weighs about 1.3 pounds (around 600 grams). That’s close to the length of an ear of corn and a little heavier than a large mango. While still small enough to fit in two cupped hands, your baby has grown dramatically from just weeks ago and is entering a critical stretch of development.
Weight and Length at 24 Weeks
The 1.3-pound, 12-inch measurement is an average. Healthy babies at this stage can be somewhat smaller or larger depending on genetics, nutrition, and placental function. Your provider tracks growth over time rather than relying on a single measurement, so small variations from the average are rarely a concern on their own.
One simple way your provider monitors growth in person is by measuring fundal height, the distance from your pubic bone to the top of your uterus. At 24 weeks, that measurement should be around 24 centimeters, give or take 2 centimeters. If the number falls outside that range, it can be an early signal to look more closely at how the baby is growing, usually with an ultrasound.
What Your Baby Looks Like Right Now
At 24 weeks, your baby is lean. There’s very little body fat yet, which means the skin appears thin and somewhat wrinkled. A fine layer of soft hair called lanugo covers much of the body, helping a waxy coating called vernix stick to the skin. That coating protects delicate skin from the amniotic fluid. Over the coming weeks, your baby will start packing on fat quickly, filling out and smoothing those wrinkles.
Facial features are well-formed by now. Eyebrows and eyelashes are growing in, and the eyes are developed, though the eyelids will stay closed for roughly another two weeks. Your baby’s face would be recognizable on a 3D ultrasound at this point.
Key Developmental Milestones
Size is only part of the picture at 24 weeks. Several organs are hitting important milestones that matter for your baby’s long-term health.
Lungs
The lungs are in a phase called the canalicular stage, where the tiny air passages and early air sacs are forming. Around 24 weeks, specialized cells in the lungs begin producing surfactant, a slippery substance that keeps air sacs from collapsing when a person breathes. Surfactant production at this stage is minimal, which is one reason babies born this early need intensive respiratory support. Over the next several weeks, surfactant levels climb steadily.
Hearing
Your baby can hear. The ears started picking up sound a few weeks ago, and by around 24 to 25 weeks, your baby may respond to familiar sounds, including your voice, with movement. Loud noises can sometimes trigger a startle reflex. This is a good time to talk, read, or play music if that appeals to you, though it’s not necessary for healthy development.
Brain and Sleep Cycles
Rapid eye movement (REM) sleep is already happening. Your baby spends much of sleep time in REM, a phase associated with brain development. The brain is growing quickly now, forming the folds and grooves that will continue to deepen through the rest of pregnancy and into infancy.
Fetal Movement at 24 Weeks
Most people feel their baby’s movements clearly by 24 weeks. If this is your first pregnancy, you may have only started noticing them in the last few weeks. Early movements often feel like gentle fluttering or swirling, but by this point many people also feel distinct kicks and jerky motions.
There’s no set number of kicks you should count each day. Every baby has its own pattern. The important thing is getting familiar with what’s normal for your baby so you can notice if something changes. Your baby still has room to somersault and change positions, so you might feel movement in different spots from one day to the next. That will shift as the baby gets bigger and space gets tighter in the third trimester.
Why 24 Weeks Is a Significant Milestone
Twenty-four weeks is widely considered the threshold of viability, the point at which a baby born prematurely has a realistic chance of surviving with intensive medical care. Survival rates for babies admitted to a neonatal intensive care unit at 24 to 25 weeks are approximately 80%, according to data from major perinatal centers. That’s a meaningful jump from 23 weeks, where the rate drops to around 60%.
Survival, however, is only one piece. Among babies born at 24 weeks, about 39% are later identified with some form of disability, and roughly 8% have a severe disability. These numbers have improved over the decades as neonatal care has advanced, but they underscore why every additional week in the womb matters. Babies born this early typically face weeks or months in the NICU, and the road can be long.
For the vast majority of pregnancies, 24 weeks is simply a reassuring checkpoint. Your baby is growing on schedule, developing the organs needed for life outside the womb, and becoming more active every day. The third trimester, starting at week 28, brings the fastest weight gain of the entire pregnancy, and your baby will roughly triple in size between now and birth.