What You Should Expect in Baby Ultrasound: Week-by-Week Review

You are here:
MyConciergeMD | What You Should Expect in Baby Ultrasound: Week-by-Week Review

You are expecting!!!

A piece of news that changes your entire life – a moment to cherish, a moment of a new beginning. The pregnancy period is the most memorable moment for every woman. A little one is growing inside you. Without even seeing, you shower the baby with every bit of your love.

During this period, your doctor will suggest many tests. Ultrasound is one of the crucial tests that informs the well-being and growth of your baby. As a new expecting Mom, all may seem new and overwhelming, including your ultrasound report. But don’t be panicked. Stay with us to get what you should expect in baby ultrasound: a week-by-week review.

What is Ultrasound?

Ultrasound, aka sonogram, is a test that healthcare providers suggest to most pregnant women to check the baby’s health and development. In the procedure, a trained technician uses a small transducer to send sound waves into your body while collecting the images that bounce back and sends those images to a computer. Ultrasound is safe, painless, and highly effective in providing valuable information about you, especially your baby inside your womb.

Ultrasound During Pregnancy

Ultrasound is a crucial prenatal test that plays a special role in your pregnancy. You can see your baby inside your womb- the movement, growth, your baby’s hands, legs, and other body parts. Doctors mostly suggest ultrasound in the second trimester at 18 to 20 weeks of pregnancy. However, some women also get an early or first-trimester ultrasound before 14 weeks.

Usually, doctors use ultrasound to detect several things that include

  • To verify you’re pregnant
  • To check your baby’s age and growth to ascertain your due date.
  • To examine the heartbeat, muscle tone, movement, and overall development of your baby.
  • To investigate if you’re pregnant with twins, triplets, or more
  • To monitor if your baby is in the heads-first position before birth
  • To examine your uterus and ovaries where eggs are stored in your body.

What You Should Expect in Baby Ultrasound: Step by Step

Your unborn baby spends almost 38 weeks in your womb. However, the average pregnancy period is 40 weeks, as pregnancy counts from the first day of your last period.

What You Should Expect in Baby Ultrasound - MyConciergeMD

The pregnancy period is distributed into three trimesters:

  • First trimester – conception to 12 weeks
  • Second trimester – 12 to 24 weeks
  • Third trimester – 24 to 40 weeks.

Let’s check what you can expect in the week-by-week ultrasound.

First Trimester

In the first trimester, ultrasounds usually confirm the pregnancy and the position of your baby. Week 1 and 2, there is no ultrasound image of your baby.

Week 3 Baby Ultrasound

3 weeks baby ultrasound detects the starting of your pregnancy. In this week, the sperm joins with the egg, and fertilization occurs inside the fallopian tube.

Week 4 Baby ultrasound

A small circle at the center of the sonogram confirms your pregnancy. However, the size is not measurable. This baby cocoon is a gestational sac that will eventually achieve shapes. But that’s a long way to go.

Week 5 baby Ultrasound

Now you can see your baby- the size of a pen dot of 1/18 to 1/16 inch. The fluid in the dark area that covers the gestational sec will convert to the amniotic fluid eventually. The white circle is the yolk sac that provides all the necessary nutrients to your baby till the placenta forms. The + marks early embryo near the sac helps the technicians to determine the due date by measuring its size. In this week, your baby’s heart and nervous system start to develop.

Week 6 Baby Ultrasound

Baby ultrasound at 6 weeks shows a significant change in the embryo with a C- shape. The baby curves inward with an umbilical cord in the middle. The head is visible on the upper right side, and the tiny buds are the developing arms and legs. 6 weeks baby ultrasound also shows a measurable heartbeat.

Week 7 Baby Ultrasound

Now your baby is 1/4 to 1/3 inch long- the size of your pinkie fingernail. The Head becomes prominent with the structures that will form the brain. Nostrils and lenses of the eyes also develop.

Week 8 Baby Ultrasound

Baby ultrasound 8 weeks shows your baby is 0.6 inches long and weighs 0.04 ounces. Can you see the embryo lying on her back with the head to the right? Your baby’s head is becoming more significant with three main parts in the brain- the forebrain, the midbrain, and the hindbrain.

Week 9 Baby Ultrasound

Your baby is almost 3/4 inch now and weighs 2 grams. You can see some facial features- the forehead has grown larger, the chin is still underdeveloped, and the toes are joined together.

Week 10 Baby Ultrasound

Baby ultrasound at 10 weeks shows your baby more like a newborn. Arms and legs are visible, ears are fully formed, and neck is developing. Now baby’s length is 1.22 inches and 0.14 ounces weight.

Week 11 Baby Ultrasound

In this ultrasound, you can see your baby’s neck is growing, separating her large head from the body. The bright white areas indicate the developing facial bones in the screen. In addition, fingers and toes are visible where the baby’s genitalia are forming but not yet visible.

Week 12 Baby Ultrasound

Your baby is now 2.13 inches long and 0.49 ounces. The facial profile is becoming more defined, and if you are lucky, you may see the baby sucking her thumb. You can also see the kidneys have started to work.

Week 13 baby Ultrasound

Almost 3 inches long and 1-ounce weight: your baby is in the last phase of the first trimester. You can see her legs are visible with bent knees. Fingerprints have formed, and sucking thumb is the regular picture now.

Second Trimester

Welcome to the second trimester. Let’s find out what you can expect in the baby ultrasound: a week-by-week review.

Week 14 Baby Ultrasound

Your baby is now 3 ¼ inches from crown to rump and weighs around 1 ounce. The baby’s head is usually visible on the right-hand side with the hand on the chest in the image.

Male or female genitalia also form this week, and the liver and spleen produce red blood cells.

Week 15 Baby Ultrasound

In the image, you can see the baby is curled up with her hands covering the face. Now she is about the size of a grapefruit- 4 to 4 1/2 inches long and weight 1 3/4 ounces. You can also see the baby’s skeletal system developing, especially the larger bone in the skull is hardening with hair pattern on the scalp.

Week 16 baby Ultrasound

Your baby’s facial feature is more defined now. She has fully formed lower limbs with forming toenails. Your sonographer can also measure the nasal bone now.

Week 17 Baby Ultrasound

You can see fetal bones are more visible on ultrasound, and you can detect each bone within her fingers.

Week 18 Baby Ultrasound

18-20 weeks are critical when your doctor will prescribe you an ultrasound. The second-trimester ultrasound images show your baby’s chest, abdomen, and brain that the sonographer measures to evaluate your baby’s growth. Your baby is now 5 to 5 1/2 inches long from crown to rump and weighs 5 1/4 ounces.

In the image, looking between Baby’s legs, the sonographer can easily detect the gender of your baby now.

Week 19 Baby Ultrasound

The ultrasound image will show that the baby’s arms and legs are now well-developed, proportionally, and adding muscle.

Week 20 Baby Ultrasound

You can find your baby may look skinny, but her development is right on track. Her nails and hair are growing, and you can feel the movement now.

Week 21 Baby Ultrasound

Your baby is now 7 ¼ inches and 10 ½ ounces with forming bones and skeletal structure. You can identify her heart and lung tissues easily now.

Week 22 Baby Ultrasound

The baby’s hair and eyebrows usually grow this week.

Week 23 Baby Ultrasound

Now your baby’s entire body image is intricate, as she’s more than 8 inches in length. Though she looks thin, she is gaining dramatic weight now.

Week 24 baby Ultrasound

Her lungs are developing, with blood flowing from the heart’s upper chambers into the heart’s lower chambers.

Week 25 Baby Ultrasound

The image of the ear shows the defined and formed feature of your baby. However, her hearing is still developing.

Week 26 Baby Ultrasound

Your baby is now 9 1/4 inches and nearly 2 pounds with growing hair and eyelashes.

Week 27 baby Ultrasound

This week is the last phase of the second trimester. Now only one trimester to go. Your baby has gained enough weight now. Her lungs are growing, the liver is evolving, and the immune system is strengthening.

Third Trimester

Welcome to the last trimester.

Week 28 Baby ultrasound

Your baby is 15 3/4 inches and weighs almost 2 1/2 pounds. You can see her hair is waving in the amniotic fluid, and her eyes are opening.

Week 29 Baby ultrasound

Are you getting kicks and jabs? Yes, your baby is growing more muscular with hardening bones and strong muscles.

Week 30 baby Ultrasound

You can see your baby’s facial feature is more defined now with visible pouty lips and a tiny nose. She also has gained much weight now- almost 3 pounds.

Week 31 Baby Ultrasound

The baby is growing with added weight. Her spinal cord is visibly shielded by the bright white bones of the spine.

Week 32 Baby Ultrasound

This week the baby starts practicing his breathing while continues to gain weight. If you look closely, her toenails are fully formed now.

Week 33 Baby Ultrasound

The ultrasound shows the developing brain where the red and blue indicate blood flow to the part of her brain. It lets the two halves of the brain communicate with one another.

Week 34 Baby ultrasound

Baby’s lungs continue to mature, and she is constantly gaining weight this week. Her total length is 19 3/4 inches, and her weight is almost 5 pounds now.

Week 35 Baby Ultrasound

You can now see the fully developed facial features of your baby, almost like the newborn baby. Her kidneys are fully formed, and the liver is operating.

Week 36 Baby Ultrasound

Not much to detect this week except for her gaining weight that is almost 6 pounds now.

Week 37 Baby Ultrasound

Your baby is officially full term with a total length of 21 inches and almost 6 1/2 pounds weight. The image will show your baby is getting a bit crowded in your womb now.

Week 38 baby Ultrasound

The image will show the baby’s major body systems are working as she continues to practice breathing in utero. Her movements will lessen as she doesn’t have enough space in your womb.

Week 39 Baby Ultrasound

Your delivery date is coming, and your doctor will check if the baby has settled into a head-down position—the best position for normal delivery.

Week 40 baby Ultrasound

The Delivery day! Your sonographer may take the abdominal circumference to evaluate your baby’s actual weight before delivery.

Bottom Line

Now you know what you should expect in baby ultrasound: a week-by-week review. However, pregnancy is a moment of excitement, joy, and fear. But on the proper hand, you can ensure the safe arrival of your baby in the world. Contact My Concierge MD, where the expert doctors will provide you with the best care, support, and treatment to bring your baby into your world.

Share this post

Book Appointment