What does the tech look for at a 21 week ultrasound?

Are you having your scan done in the doctor's office or in an imaging department or center? In a doctor's office, the scan will not include everything I have listed. For a second trimester OB ultrasound, where I work (in a free standing imaging center in CA), we document these things:

**cervical length, placenta, amnionic fluid levels

**measurements: 2 of the baby's head and 1 each of the abdomen and femur to get an estimated fetal age and weight

**fetal organ survey - urinary bladder, 2 kidneys, stomach bubble, fetal cord insertion, 4 chambered heart, outflow tracts of the heart, diaphram, aorta and aortic arch, nasal bone, both eye lenses, structures of the brain (posterior fossa, ventricle), the entire fetal spine in two different views or planes, entire lower and upper extremities on both arms/legs

***we document the fetal heart rate

***we document that you have a 3 vessel umbillical cord and do doppler wavelengths on the cord

***maternal gallbladder, as pregnant women have a higher rate of gallstones

***of course, if the mother wishes, we try to determine the fetal sex. If you do not want to know the sex, tell the sonographer before she starts scanning you. If a patient does not want to know the sex, I don't even look, as it is not medically important!

I hope you enjoy your ultrasound experience!

An ultrasound at 21 weeks would be to take measurements to see if the baby is growing properly. They will also check your amniotic fluid levels and the anatomical structures and organs of the baby for abnormalities.

You don't have to have the ultrasound if you don't want. With my last 2 pregnancies, I haven't gotten one. My insurance won't cover it anyway, unless there is a medical need or complication.

But if you do go, tell them right when you walk in the door VERY clearly "we do not want to know the sex of the baby" so they won't slip up and let the secret out.

21 Week Ultrasound

RE:

What does the tech look for at a 21 week ultrasound?

I am scheduled to have an ultrasound at 21 weeks. What does the doctor look for? Is it only to determine the sex? We don't want to know what we are having so do I still need one? I didn't have one with my daughter and she was fine.

They take measurements of the baby's head circumference, femur length, and other measurements, they check to make sure you have enough amniotic fluid, they check certain organs of the baby to make sure they are properly developed (brain and skull formation are the most important, then heart, then kidneys, then other structures like limbs, etc.), they check the location of the placenta; high, low, anterior (front) or posterior (back), and sometimes they are able to check the cord to verify there are 3 vessels.

If you're fortunate they will see the sex, but that's just a bonus. They don't do scans for that sole purpose.

It is both the things the top two answerers said: external features and internal organ development. At mine, they used different imaging to be sure all four chambers of the heart were operating correctly, counted toes, checked facial structure and measured like crazy.

With today's technology, it might be hard NOT to know the sex - I could see it for myself (boy!).

No, it is not technically necessary, but there are some problems they can detect that you can be prepared for. They typically do another one around 34 weeks to determine the baby's position, if the cord is wrapped around the neck, and size of the baby.

Usually around this time it's an extensive ultrasound to make sure all of the organs are present and in the right place. It takes a long time and they can tell you the sex but only if you want them to. Since you don't want to know, tell them immediately so they don't accidentally tell you.

They look for several things. Of course if you want to know the sex of the baby, the genitals at this point would be developed enough versus 16 weeks. They also check the measurements of the fetus; legs, arms, crown to rump length, head...etc. Which will ensure the fetus is growing properly. They are also able to see anything that may be abnormal.

They are safe but it's totally up to you if you want to have one.

They look at a few things... they get definite outlines of lips, ears, nose, fingers, etc. You may not need one, but you could always ask your doctor if you can opt out. Also make sure your doctor knows that you don't want to know the gender, otherwise someone might slip up and tell you anyway.

Check the organs and make sure that the body is growing symetrical and properly. Also makes sure the aminiotic fluid levels are correct. Takes about 45 minutes and it very interesting