At 35 weeks pregnant, your baby measures about 18.2 inches long from head to heel and weighs roughly 5.3 pounds, close to the size of a honeydew melon. That’s a significant jump from just a few weeks ago, and your baby is now gaining about half a pound per week as the final stretch of pregnancy begins.
Size and Proportions at 35 Weeks
Most of your baby’s length is already achieved by this point. The remaining weeks are largely about filling out. Fat is accumulating under the skin, rounding out the arms, legs, and face. This fat layer does more than add weight. It helps your baby regulate body temperature after birth, which is one of the key challenges for babies born before full term.
To put the size in perspective, your baby now takes up most of the available space in your uterus. If you’ve been measuring fundal height at your prenatal appointments (the distance from your pubic bone to the top of your uterus), that number in centimeters generally tracks closely with your week of pregnancy, give or take about 2 centimeters. So at 35 weeks, you’d expect a measurement somewhere around 33 to 37 centimeters.
Why the Brain Is Still Growing Fast
Your baby’s brain at 35 weeks weighs only about two-thirds of what it will weigh at 39 to 40 weeks. That’s a massive amount of brain growth still to come in just four or five weeks. During this period, the brain is forming the deep grooves and folds that increase its surface area, building the neural connections that support breathing, feeding, temperature regulation, and all the coordinated skills a newborn needs.
Your baby is also still learning to suck and swallow in a coordinated way. These reflexes might seem simple, but they require precise timing between multiple muscle groups and the brain signals that control them. Babies born at 35 weeks sometimes struggle with feeding for this reason.
Lung Development at This Stage
The lungs are one of the last organs to fully mature, and 35 weeks is a meaningful milestone. By this point, lung development is typically sufficient to support breathing outside the womb. Your baby’s lungs have been producing surfactant, a slippery substance that coats the air sacs and keeps them from collapsing each time your baby takes a breath. Production ramps up significantly after 28 weeks, and by 35 weeks the lungs contain far more surfactant per volume than an adult’s lungs, essentially stockpiling it in preparation for that first breath of air.
That said, “sufficient” doesn’t mean “fully mature.” Some babies born at 35 weeks still need temporary breathing support while their lungs finish the job. The final stage of lung development, where the smallest air sacs multiply and thin out to allow efficient oxygen exchange, continues right up to and even after birth.
Movement Feels Different Now
Your baby is running out of room. At 35 weeks, most babies have settled into a head-down position, with their feet up near your ribs. You may feel sharp kicks under your ribcage, which can genuinely hurt. Some women describe rib soreness that lingers even between movements.
The movements themselves may feel different from the acrobatic flips of the second trimester. With less space to work with, you’re more likely to feel rolls, stretches, and firm pushes rather than full-body turns. But the movements should still be just as strong and just as regular as they’ve been in previous weeks. A noticeable drop in activity is always worth paying attention to, regardless of how cramped things are getting in there.
What Happens if a Baby Is Born at 35 Weeks
A baby born at 35 weeks falls into the “late preterm” category (34 to 36 weeks). These babies generally do well, but they aren’t quite full term and often face a short list of common challenges. Trouble staying warm is one of the most frequent issues, since that insulating fat layer is still building. Feeding difficulties are another, tied to those still-developing suck and swallow reflexes. Some late preterm babies experience brief pauses in breathing, a condition called apnea of prematurity, or develop mild anemia.
Many babies born at this stage spend time in a neonatal intensive care unit, not because they’re critically ill but because they need monitoring and support while they finish maturing. The stay is often relatively short. Vision and hearing are also areas to watch, since babies born before full term have a higher likelihood of problems in both.
What’s Happening in Your Body
With a baby the size of a honeydew melon pressing on your organs, you’re likely feeling the physical toll. Your uterus now reaches well up under your ribs, which can make deep breaths feel harder to come by. Heartburn, frequent urination, and lower back pain are all common at this stage simply because of the space your baby is occupying. Some women also notice increased pelvic pressure as the baby drops lower in preparation for delivery.
You might be gaining about a pound per week yourself, though much of that is your baby’s growth, increased blood volume, and fluid. The placenta is fully mature and working hard, delivering nutrients and oxygen through the umbilical cord to support this final growth spurt. Your baby’s kidneys are now producing urine that makes up a large portion of the amniotic fluid, and those practice breathing movements are pulling that fluid in and out of the lungs dozens of times a day.