At 27 weeks pregnant, your baby is about 13¾ inches (35 cm) long from head to heel and weighs roughly 2¼ pounds (1 kg). That’s close to the size of a head of cauliflower. Your baby has tripled in weight since the start of the second trimester and is now entering the final stretch of pregnancy, the third trimester, where rapid weight gain becomes the main event.
What 2 Pounds Looks and Feels Like
Two and a quarter pounds may not sound like much, but at this stage your baby is fully formed and putting on fat beneath the skin. Most of the weight gain from here to delivery, when your baby will likely weigh between 6 and 9 pounds, happens in these last 13 weeks. Your baby is gaining roughly half a pound per week now, and that pace will accelerate over the coming months.
Your healthcare provider may measure your fundal height at appointments, which is the distance from your pubic bone to the top of your uterus. At 27 weeks, that measurement is expected to be about 27 centimeters, give or take 3 centimeters. A measurement outside that range doesn’t necessarily signal a problem, but it can prompt an ultrasound to check on growth more precisely.
Brain and Nervous System Growth
The nervous system is actively maturing at 27 weeks. Brain tissue is folding into the grooves and ridges that increase its surface area, and your baby is developing more coordinated movement patterns as a result. Sleep and wake cycles are becoming more distinct, so you may notice your baby is active at predictable times of day.
Your baby’s eyes, which have been forming for weeks, are now capable of opening and closing. The retinas can detect changes in light, so if you shine a flashlight at your belly, your baby may respond by turning or shifting. This light sensitivity is one of the earliest signs that the visual system is coming online.
Lung Development at 27 Weeks
The lungs are one of the last organs to fully mature, and at 27 weeks they’re still a work in progress. Specialized cells in the lungs have been producing surfactant, a slippery substance that keeps the tiny air sacs from collapsing, since around 20 to 24 weeks. The amount of surfactant increases steadily from that point through the end of pregnancy. At 27 weeks, there’s enough surfactant to give a baby born early a fighting chance at breathing, but not enough for easy, independent breathing. Babies born at this stage almost always need respiratory support.
Movement Patterns to Expect
By 27 weeks, you’re likely feeling regular kicks, rolls, and jabs. There’s no magic number of movements to count each day. What matters more is learning your baby’s typical pattern. Some babies are more active in the evening, others after meals. Once you have a sense of what’s normal for your baby, a noticeable change in that pattern, like a long stretch of unusual stillness, is worth paying attention to.
Your baby still has room to move around at this point and hasn’t settled into a final position. Many babies are still head-up (breech) at 27 weeks, which is completely normal. Most will flip to a head-down position on their own before 36 weeks.
What Happens if a Baby Is Born at 27 Weeks
No one plans for a baby to arrive this early, but it’s natural to wonder about survival if something unexpected happens. The outlook for babies born at 27 weeks is genuinely encouraging. In a large study of more than 10,000 extremely preterm infants born across U.S. research centers, survival rates for babies born between 22 and 28 weeks reached 78%, with outcomes improving at each additional week of pregnancy. By 28 weeks, survival was 94%, and 27-week babies fall just below that threshold.
Survival is only part of the picture. Among preterm survivors assessed at age 2, nearly half had no or only mild developmental issues. About 29% had moderate neurodevelopmental challenges, and roughly 21% had severe impairment. Around 8% were diagnosed with moderate to severe cerebral palsy. These numbers reflect the full range of extremely preterm births (22 to 28 weeks), so outcomes for babies born closer to 28 weeks tend to be better than the averages suggest.
A baby born at 27 weeks would spend weeks in the NICU, primarily to support breathing and feeding while the lungs and digestive system finish maturing. The hospital stay typically lasts until close to the original due date, though every baby’s timeline is different.
How Your Body Reflects Your Baby’s Size
With your baby now over a foot long and gaining weight quickly, you’re feeling the effects. Your uterus has expanded well above your belly button, which can push against your diaphragm and make deep breaths feel harder. Heartburn, back pain, and leg cramps are common at this stage, all connected to the growing demands your baby is placing on your body.
You may also notice your belly tightening periodically. These are Braxton Hicks contractions, practice contractions that are irregular and painless. They’re your uterus rehearsing for labor and are completely normal in the third trimester. They tend to increase with activity or dehydration and ease up with rest.