Pregnancy Pregnancy Development Third Trimester Ultrasound Pictures Take a sneak peak at your baby's development with this slideshow of ultrasound pictures from the third trimester of pregnancy. By Kristen J. Gough Updated on June 26, 2023 Trending Videos Close this video player While most expecting parents would love to get a look at their baby-to-be on a weekly (or daily) basis, it's customary to only receive one or two ultrasounds during pregnancy. Luckily, looking at ultrasound images of other babies, say at 30-week or 34-week ultrasounds, can still give you a very close approximation of what your baby looks like and what's happening with their growth and development. Enter our slideshow of the third trimester of pregnancy, made in conjunction with the American Institute of Ultrasound Medicine (AIUM), Johns Hopkins, and the March of Dimes. This array of images gives you a look at each week of development to reveal all the intricate details of your baby's growth—until you get to meet them in person. 01 of 17 28 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 10 inches, crown to rump; total length 15 3/4 inches. Weight, almost 2 1/2 pounds Fetal Development Milestones: Your baby now has added brain tissue and their scalp hair is continuing to grow. Their eyes are opening and they're gaining weight. What You're Seeing: Your baby-to-be's hair is seen waving in the amniotic fluid. This hair is called lanugo. Unfortunately, we can't predict how much hair your baby will have because he will lose his lanugo before being born and it will be replaced with the hair we're used to seeing on infants at birth. Third Trimester Ultrasound Pictures 02 of 17 29 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 10 1/2 inches, crown to rump; total length 16 3/4 inches. Weight, 2 3/4 pounds Fetal Development Milestones: Your little one's muscles are maturing. They'll continue to gain weight over the coming weeks. What You're Seeing: At 29 weeks, your baby-to-be's bones are hardening, and they're muscles strengthening. In fact, you may have noticed from their kicks and jabs that they're growing stronger each week. Bones appear bright white on a sonogram. Although you can't see it in this image, your baby has probably been practicing their breathing movements this week, though their lungs still need more time to mature. 8 Common Pregnancy Myths You Can Ignore 03 of 17 30 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 10 3/4 inches, crown to rump; total length 17 inches. Weight, 3 pounds Fetal Development Milestones: At a 30-week ultrasound, it's clear that the baby's eyes are opening and they're gaining weight. What You're Seeing: This image shows how developed your baby-to-be's features have become. With their pouty lips and tiny nose, they look a lot like they will at birth. Note the baby's hand in front of their eyes and forehead. Normal Fetal Movement During Pregnancy 04 of 17 Sleep Cycles: Weeks 26 to 30 of Pregnancy 05 of 17 31 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 11 3/4 inches, crown to rump; total length almost 18 inches. Weight, 3 1/2 pounds Fetal Development Milestones: At 31 weeks, your baby continues to develop as they gain weight. What You're Seeing: This image gives a close-up view of the lower end of your unborn baby's spine. You can see the spinal cord protected by the bright white bones of the spine. This Is What Your Baby Experiences During Labor and Delivery 06 of 17 32 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 11 1/2 inches, crown to rump; total length 19 inches. Weight, 4 pounds Fetal Development Milestones: Baby's toenails are now formed, they're practicing their breathing, and they're continuing to gain weight and grow. What You're Seeing: There's not much to report on your baby-to-be's developmental milestones this week. Much of their growth is strictly adding weight through fat layers that will insulate their maturing organs. They'll need plenty of fat tissue to keep them warm once he leaves their home in your womb and enters the world, where the environmental temperature is not as controlled. Although you can't see it in this image, your baby has probably been attempting to breathe this week, though his lungs still need more time to mature. Another development you'll notice in this image—look closely and you might spy the edges of his toenails, which are now fully formed. Week 32 Ultrasound: What It Would Look Like 07 of 17 33 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 12 inches, crown to rump; total length 19 1/2 inches. Weight, 4 1/2 pounds Fetal Development Milestones: Your baby is getting more plump each day. What You're Seeing: Your baby-to-be's brain is continuing to grow and develop. In this image, the red and blue show blood flow to the part of his brain that lets the two halves of the brain communicate with one another. Third Trimester Ultrasound Pictures 08 of 17 34 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 12 3/4 inches, crown to rump; total length 19 3/4 inches. Weight, 5 pounds Fetal Development Milestones: Baby's lungs are continuing to mature and they're continuing to gain weight. What You're Seeing: In this image of a profile, the baby's mouth is open. They may be drinking amniotic fluid or taking it into their lungs, which aids in the development of their respiratory system. Pregnancy 09 of 17 Growing Big: Weeks 31 to 34 of Pregnancy 10 of 17 35 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 13 1/4 inches, crown to rump; total length 20 1/4 inches. Weight, 5 1/4 pounds Fetal Development Milestones: The baby's kidneys are fully developed and their liver is functioning. They continue to add weight each week. What You're Seeing: This closeup shot of your baby-to-be's ear shows how fully developed their facial features have become. They now look like the newborn that you'll be welcoming into the world in a few weeks (only five more to go!). Your baby is also maturing on the inside too. They continue to practice their breathing movements, which move amniotic fluid in and out of their lungs to aid in their development. Week 35 of Your Pregnancy 11 of 17 36 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 13 1/2 inches, crown to rump; total length 20 3/4 inches. Weight, 6 pounds Fetal Development Milestones: Not much new to report at 36 weeks! Your baby continues to gain weight. What You're Seeing: This image of your baby-to-be's face looks identical to the profile you'll be seeing in person in a few weeks (four or less!). For the remaining weeks, your baby will be adding 1/2 pound each week until birth. Are You Having a Big Baby? 5 Signs to Know 12 of 17 37 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 14 inches, crown to rump; total length 21 inches. Weight, 6 1/2 pounds Fetal Development Milestones: At 37 weeks, our baby is officially full-term! What You're Seeing: Sometimes, your doctor or midwife will ask for a test to check how well your baby is doing. One indicator of your baby-to-be's well-being is a measurement of the amniotic fluid. This can also be part of a test called a biophysical profile, which will also include watching the baby's various movements. In this image, the sonographer is measuring the deepest pocket of fluid in each of the four areas of your uterus. As you can see, your baby is getting a bit crowded in there! Here's Why You Should Aim for a Full-Term Pregnancy, If Possible 13 of 17 38 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 14 inches, crown to rump; total length 21 inches. Weight, 6 3/4 pounds Fetal Development Milestones: All of your baby's major body systems are working, and they're continuing to practice breathing in utero. Their movements will lessen as they run out of space. What You're Seeing: During the last few weeks of gestation, your baby has less and less room to move. A few weeks (and pounds) ago, they may have been kicking and wiggling constantly; now they simply don't have enough room. If you or your healthcare provider have any concerns about your baby's development, especially if their movement becomes too infrequent, you may have an ultrasound to check up on them. This image shows the results of monitoring a baby's heart rate in utero. At the top, the baby's heart beats; below, the lined measurements track and then determine the baby's heart rate to make sure it's within the normal range. What Are the Different Types of Contractions? 14 of 17 39 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 14 1/2 inches, crown to rump; total length 21 1/2 inches. Weight, around 7 pounds Fetal Development Milestones: At 39 weeks, your delivery day is coming soon! What You're Seeing: What you're seeing: The sonographer is getting a 3/4 view of your baby-to-be's face, and you can actually see their eyelashes! Your medical provider may want to see if the baby has settled into a breech position or head-down position, which is the ideal position for normal delivery. Third Trimester Ultrasound Pictures 15 of 17 40 Week Ultrasound American Institute of Ultrasound in Medicine - AIUM.org Fetal Size: Length, 14 3/4 to 15 1/4 inches; total length 21 1/2 inches. Weight, 7 1/2 pounds Fetal Development Milestones: Delivery day! What You're Seeing: If your healthcare provider wants to get an idea of your baby's weight, one of the most important measurements the sonographer can take is abdominal circumference. This image is a cross-section of your baby's belly. The small back oval of their stomach, and the curved black line is the blood vessel that brings nutrients from the placenta. Soon, you'll have a very different way of feeding your baby! Finding Out Your Baby’s Sex With an Ultrasound 16 of 17 Your Baby Is Almost Here: Week 35 of Pregnancy to Birth Are Ultrasounds Safe for Babies During Pregnancy? 17 of 17 More About Prenatal Ultrasounds American Institute of Ultrasound in Medicine - AIUM.org All ultrasound images were provided by the sonographers of the Johns Hopkins Maternal-Fetal Diagnosis and Treatment Center. We are grateful to Christine Bird, BS, RDMS, RVT, chief obstetrical sonographer, and Jude Crino, M.D., medical director, for their assistance with this project. For examples of prenatal ultrasounds and more information on your baby's fetal development, be sure to visit www.aium.org and www.marchofdimes.org. Parents: Trusted Parenting Information for Raising the Future Key Takeaways These ultrasound images of each week of the third trimester give you a look at your baby's growth and development for the last third of pregnancy. Was this page helpful? Thanks for your feedback! Tell us why! Other Submit