At 28 weeks pregnant, your baby measures about 10 inches (25 centimeters) from the top of the head to the bottom of the tailbone, and weighs roughly 2¼ pounds (1,000 grams). Measured from head to heel with legs extended, that’s closer to 14 to 15 inches total. For a quick visual, picture a large eggplant. You’re now entering the third trimester, and your baby is growing fast from here.
How Size Is Measured at 28 Weeks
Fetal measurements can be confusing because doctors use two different reference points. Crown-to-rump length measures from the top of the head to the bottom of the tailbone, ignoring the legs. That’s the 10-inch figure. Crown-to-heel length includes the full body with legs straightened out, which adds several more inches. Earlier in pregnancy, crown-to-rump is more common because a baby’s legs are curled tightly. By the third trimester, crown-to-heel becomes the standard, putting your baby in the 14- to 15-inch range.
Weight varies quite a bit from one pregnancy to the next. Two and a quarter pounds is an average, but healthy babies at 28 weeks can weigh somewhat more or less. Your provider tracks growth over multiple ultrasounds rather than relying on a single snapshot, looking for a consistent upward trend on the growth curve.
What Your Baby Looks Like Now
At this stage, your baby has filled out considerably compared to just a few weeks ago. A layer of fat is building under the skin, smoothing out the wrinkled appearance and helping regulate body temperature. Eyelashes and eyebrows are in place, and the head may already have a thin layer of hair. The skin is still somewhat translucent but becoming more opaque as fat deposits increase.
Your baby’s eyes are now open and can detect light filtering through the uterine wall. Research from UC Berkeley’s School of Optometry found that babies in the womb can perceive light well before their eyes are capable of forming images, and by 28 weeks that sensitivity is well established. If you shine a flashlight at your belly, your baby may respond by turning or moving.
Brain and Lung Development
The brain is in a period of explosive growth during the late second and early third trimester. The surface of the brain, previously smooth, is developing the characteristic folds and grooves that increase its surface area. Your baby is now cycling through periods of sleep and wakefulness, including REM sleep, the phase associated with dreaming. Brain wave patterns at 28 weeks are increasingly complex and begin to resemble those of a newborn.
The lungs are one of the last organs to fully mature, and at 28 weeks they’re still a work in progress. Your baby’s lungs are beginning to produce surfactant, a slippery substance that keeps the tiny air sacs from collapsing when a baby breathes. Production at this stage is still quite limited. Babies born at 28 weeks or earlier typically have a severe deficiency in surfactant, which is why premature infants often need breathing support. The good news: with each passing week, the lungs make significantly more, and viability is strong at this point. About 94% of babies born at exactly 28 weeks survive to hospital discharge with modern neonatal care.
Fetal Position at 28 Weeks
Don’t worry if your provider mentions that your baby is breech right now. About 25% of babies are still in the breech position (feet or bottom down) before 28 weeks. Most flip on their own as they grow. By 32 weeks, only about 7% remain breech, and many of those will still turn head-down before delivery. Your baby has plenty of room to somersault for several more weeks, so breech positioning at this stage is not a concern.
What You’re Feeling
By 28 weeks, your baby’s movements are strong enough that other people can often feel them from the outside. Kicks, rolls, and stretches are becoming more predictable as your baby settles into sleep-wake cycles. This is the point in pregnancy when many providers recommend starting kick counts. The guideline is straightforward: pick a time when your baby is usually active, and note how long it takes to feel 10 movements. Kicks, flutters, swishes, and rolls all count. Most babies hit 10 within an hour. If two hours pass without 10 movements, that’s worth a call to your provider.
Your uterus has grown substantially to accommodate all this development. A quick way to gauge growth from the outside is fundal height, the distance from your pubic bone to the top of your uterus. At 28 weeks, that measurement should be close to 28 centimeters, give or take 2 centimeters. Your provider will check this at your prenatal visits as a simple screen for whether growth is on track.
Growth Over the Coming Weeks
Your baby will roughly double or even triple in weight between now and delivery. At 28 weeks, that 2¼-pound frame will steadily pack on about half a pound per week going forward, with the most rapid weight gain happening in the final six to eight weeks. Most of that added weight is fat, which your baby needs for temperature regulation, energy reserves, and that characteristic newborn chubbiness. Length increases more gradually, adding about half an inch per week, with most full-term babies arriving at 19 to 21 inches.
The third trimester is when everything refines. Bones harden (though the skull stays flexible for delivery), the immune system picks up antibodies from your bloodstream, and the digestive system practices by processing swallowed amniotic fluid. Your baby is fully formed at this point. The remaining 12 weeks are about growth, maturation, and getting ready for life outside the womb.