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Ultrasound Information
Ultrasound: What it is and what it isn't.
  • Ultrasound is a wonderful tool that has revolutionized the field of Obstetrics and Gynecology. However it is often a source of confusion for our pregnant patients. The following information should answer some commonly asked questions and hopefully eliminate confusion before it begins.
Due Date:
  • You only have one real "due date", regardless of how many ultrasounds you have.
  • The most accurate way for us to know your real due date is when you know for sure when the FIRST day of your LAST menstrual period was. Ultrasound is meant to CONFIRM (not change) the due date that is calculated based on your last menstrual period. The accuracy of ultrasounds varies depending on when it is done. For example, in the first trimester, if there is more than 1 week's difference in how far along you are (based on your last period) compared to the ultrasound, we would change your due date. That same ultrasound, done in the 3rd trimester would have to be different by more than 3 weeks (!!) for us to change your due date. Small differences between your real due date and what ultrasound tells us of a few days even up to a couple of weeks can be NORMAL and does not necessarily mean your due date has changed. Ask your doctor if you have questions but remember, you only have one true "due date".
The following is a very common question:
My friend has had 5 ultrasounds and I haven't had any. Why?"
  • The American College of Obstetrics and Gynecology does not recommend routine ultrasound in "low risk" patients. Studies have failed to show any improvement in outcome for moms or babies by doing ultrasounds on everyone. Despite this, we are now ordering ultrasounds on all of our patients, typically between 18-20 weeks, so as to assess your baby's anatomy and confirm your due date. As always, ultrasound is performed routinely on any patient whose pregnancy is complicated in any way. We do not do routine ultrasound for the purposes of determining the sex of your baby (although we are happy to check should we be doing an ultrasound for some other reason). If you have questions regarding ultrasound, please ask us: we're here to help!

Phone Numbers
Clinic Phone
(785) 239-7794
Labor & Deliver
(785) 239-7164

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This Web site provides an information regarding Irwin Army Community Hospital and its services. Irwin Army community Hospital is a U.S. Army Medical Department hospital. This website is intended for interested members of the public, news media and Army Medical Department beneficiaries.

Irwin Army Community Hospital
600 Caisson Hill Road, Fort Riley, Kansas 66442
(785) 239-7000