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    Obstetric (OB) Ultrasound

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    What is an OB Ultrasound?

    An obstetric (OB) ultrasound is a diagnostic examination performed during pregnancy by a doctor or specialized technician. Ultrasound, also called sonogram, uses high frequency sound waves sent into the body through a transducer or scanner that is placed on the skin. These sound waves are reflected off the internal organs or structures inside the body and converted into an image on a television screen in real time.

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    Why am I Having an Ultrasound?

    Ultrasound examinations are performed for a variety of reasons. Most commonly, ultrasound examinations are done during pregnancy to help your doctor determine when your baby is due and to make sure the baby is developing as he/she should.

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    Does an Ultrasound Examination Guarantee that my Baby is Normal?

    No. Detecting abnormalities is dependent upon many things. Some types of abnormalities cannot be seen on ultrasound examination because they are either too small or not visible by ultrasound. Sometimes, the size and position of the baby may prevent certain abnormalities from being seen as well.

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    Is Ultrasound Safe?

    To date, there are no confirmed adverse effects in humans caused by exposure to diagnostic levels of ultrasound. However, it is recommended that ultrasound be used only where medical benefit is expected. Please be sure to discuss this with your doctor. As an informed patient, it is important that you understand why your doctor has referred you to have an ultrasound examination.

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    Where do I go for my OB Ultrasound?

    OB/GYN Ultrasound Department
    3700 California Street
    4th Floor, 4 East, Room 4360 (take the "A" elevator)
    San Francisco

    • You may park your car in the garage at 3838 California Street, or in the garage on Cherry Street.

    • You may drive to and from the exam.

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    When Can I Get my Results?

    The results of your ultrasound may be discussed with you at the time of your examination OR you may need to discuss them with your referring doctor. In either case, the results are mailed to your obstetrician soon after your examination.

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    How Can I Learn More About this Procedure?

    Note: This handout is also available in Chinese, Russian, and Spanish.

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    Frequently Asked Questions


    Question: What is an OB ultrasound?
    Answer: An OB ultrasound is a diagnostic test performed during pregnancy.

    Question: Where do I go for my ultrasound?
    Answer: OB/GYN Ultrasound Department – 3700 California St, 4th floor, 4 East, Room 4360 (take the "A" elevator).

    Question: When can I get my results?
    Answer: You may get your results at the time of your ultrasound examination. You may need to discuss the results with your obstetrician.



    Produced by the Center for Patient and Community Education in association with the staff and physicians at California Pacific Medical Center. Last updated: 5/04


    Funded by: A generous donation from the Mr. and Mrs. Arthur A. Ciocca Foundation.

    Note: This information is not meant to replace any information or personal medical advice which you get directly from your doctor(s). If you have any questions about this information, such as the risks or benefits of the treatment listed, please ask your doctor(s).

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