16 Week Ultrasound What to Expect

The following is a list of what you can expect from a 16-week ultrasound:

At 16 weeks, you may still not be able to tell if you are having a boy or a girl without an ultrasound. Your baby will start to look more like a human and less like a tadpole.

Baby’s growth is almost complete and now measures approximately 9.6 inches in length, up another 0.5 inches since week 15.

Your fetus will gain about 7 ounces this week and will have doubled his weight since week 11.

It’s time to celebrate because your baby has grown his/her most important body parts: your baby’s brain and spinal cord. This is big news! Major organs like the heart, intestines, pancreas, and kidneys have already begun to form, but they will continue to grow this week, too.

Why 16 week Ultrasound is needed?

What is the average length of pregnancy? In humans, the average length of pregnancy is 280 days from the date of conception to birth (38 weeks). This is based on the normal range of 40 weeks. During the 40th week all the organs are fully developed and baby’s weight gains dramatically. So, it is just the last phase of pregnancy. In fact, 16 Weeks Ultrasound will be a milestone in the development of your baby. So what exactly happens at 16 weeks?

In the 16th week of pregnancy, you will probably feel tired and uncomfortable because of frequent trips to bathroom. The baby also grows rapidly this week and starts to get used to life in your womb. The fetus will move a lot and you may experience some sharp pangs in your belly.

This is one of the most important weeks for your baby’s eyesight.

How to do an ultrasound

Preparing for the 16-week ultrasound is easy.

Transabdominal scanning uses a transducer to move over your abdomen and display 2D images. The scan is noninvasive and will not harm you or your baby. However, it can cause some discomfort if the technician has to press down harder.

The ultrasound procedure will take between 30 and 60 minutes. Your doctor or an ultrasound technician, also known as a sonographer, will perform the procedure.

  • Take measurements of your baby
  • Check the development of their spines
  • Reconfirm their heartbeat

All this is to make sure that everything is moving along the right track.

You might be asked to move and turn depending on the baby’s position so that the technician can see different angles.

They will also test for fetal movements. If your baby is not very active, your sonographer may gently poke your abdomen to encourage them to move.

What You can expect to see

A 16-week scan will show a fully formed baby, but a very small one. If the baby’s development is on track, however, you can still see their arms, legs and fingers during the ultrasound.

If you are able to get your baby to cooperate with your request, your technician will be able to help you determine your baby’s sex. The genitalia must be visible from certain positions. This may need to be confirmed later.

How big should your baby?

Your baby will be 16 weeks old when he or she is approximately 4 to 5 inches in length and around 5 ounces in weight.

Your physician will measure your fundal height during your 16-week ultrasound. However, this is usually done at 20 weeks.

This noninvasive measurement measures the distance in cm from your baby’s top to your pubic bone. This measurement confirms that your baby’s growth is normal.

Your fundal height will be the same as your gestational week by the 24th week. If you are 27 weeks pregnant, your fundal height would be 27 centimeters.

There is a margin for error when measuring. It is not unusual for the numbers to not match your fundal height and gestational week, especially if they are not before the 24th week. This also has to do the accuracy of your due dates.

Your due date is an imperfect measurement with its own margin for error. It will be easier to predict your due date if you have an ultrasound done early in pregnancy.

All this to say, don’t be panicked if your baby measures a week off in one direction. It’s normal.

What other things might a doctor want to look for?

If you have one, the 16-week ultrasound is a crucial time when your doctor will be looking for potential developmental abnormalities. As we have already mentioned, they do this by taking measurements and checking movement.

The 16-week appointment is not invasive. However, your doctor may recommend that your blood be drawn for a triple or quadruple screening to rule out potential abnormalities such as Down syndrome or neural tube problems.

Screenings are usually conducted between the 15th to 20th weeks, however screens that are done between 16-18 weeks are considered the most accurate.

If the results of your blood tests indicate that there is a problem, your OB might recommend more invasive diagnostic tests like amniocentesis and chorionic villus sampling. They may also recommend additional noninvasive prenatal testing.

CVS and amniocentesis are extremely effective in confirming developmental abnormalities. However, there are small risks that could cause miscarriage or complications during pregnancy. For initial screening, doctors prefer to use noninvasive methods such as ultrasound.

Using Ultrasound To Determine Sex

You can usually determine the sex of your baby during the 16-week ultrasound if you don’t mind being surprised. It should be accurate because your baby’s exterior anatomy is perfectly formed.
Keep in mind, however, that your doctor or an ultrasound technician might not be able take a clear reading of your baby’s anatomy to confirm the sex.

If the sonographer can’t get a clear reading then your doctor will check the baby sex during a blood screening. You may also request a follow-up ultrasound to confirm.

If Expecting Twins in 16 Week Ultrasound

As with twins being born to a parent who has one child, the 16-week ultrasound will show both of your babies clearly.

Don’t be surprised if your scan takes longer than expected. Your technician must be very precise to ensure that they are taking accurate measurements and correctly labeling each child.

Your babies should be approximately the same size and length as your “singletons”, which is the medical term for a single-baby pregnancies.

Many OBs have a different growth chart for twins, as multiples often birth at a smaller size than babies born from one birth.

Don’t be surprised if one of your twins is smaller than the other. This is normal and is not cause for concern.

The Takeaway

A 16-week ultrasound can often be your first glimpse at your baby. This important milestone can help ease anxiety and make the entire pregnancy experience more real.

This ultrasound, while noninvasive and not invasive, is an important step in screening for developmental abnormalities or to confirm that the baby is growing normally.

Although not all pregnancies will include a 16 week ultrasound, most likely, this step will be completed at some point during the 16- to 20-week gestation period.

Leave a Comment