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Too Heavy For an Ultrasound?

QUESTION

Dear Ms Ultrasound,
I was scheduled for a first trimester screening in my 11th week due to my advanced age; unfortunately, the perinatologist was of very little help because he basically lectured me on how difficult it is to do ultrasound in obese patients!

I learned very little about the status of my baby. He was unable to do the screening because the baby was measuring slightly too small. He then went on to discuss amniocentesis, but why would I allow him to put a needle in my uterus guided by an ultrasound that he already told me would not be accurate?

My question is: Is it a waste of time to even get ultrasounds when one is very obese? Can't they distinguish major anatomical abnormalities in a fetus? My next US will be at 19 weeks. Will this show me anything? Thank you for your time.Robin

ANSWER

Hi Robin,
I'm sorry to hear you had such an insensitive physician treating you.

Let me explain how ultrasound works so you have a better understanding.The camera or what is called "transducer" is what is rubbed over your tummy during an exam. This transducer sends out thousands of sounds waves. The sound waves hit all tissue it passes through and then return to the tranducer to tell us, in picture form, what it hit. The best images are produced when all the sounds waves sent out return to the tranducer. This rarely happens because the sound waves hit alot of tissue, bowel, air, etc and are deflected away from the transducer.

The closer you get to the body part you are imaging the better the chance of all the sounds waves coming back. This is what your doctor tried to tell you in a rude manner. What he should have done is an internal or vaginal ultrasound. This is when a cylindrical transducer is gently placed inside the vagina. All body types will produce nice images this way as you get very close to the uterus and fetus.

As far as your doctor doing the amniocentesis, you have two options:

  1. Change doctors.
  2. If you know this is a good physician, know that your child and uterus will have grown, be closer to you skin line and have the amniotic fluid(fluid around the fetus) to help produce diagnostic images.

Hope this has helped you understand better.

-- Jane, RDMS

Jane Foley

Jane Foley has worked as a Sonographer (Ultrasound Technologist) since 1979. Jane has lived and worked in many parts of the world including Saudi Arabia. She is a Registered Diagnostic Medical Sonographer or RDMS. She pulls a wealth of information from her experience in the field of Radiology and her interactions with such a broad cross-section of cultures she has visited. She now makes her home on the island of Maui with her English husband, Michael.