U.S. doctors online nowAsk doctors free
A 22-year-old female asked:

Ultrasound at 32 weeks. due date was sept 12th and changed to sept 10th. does this mean i conceived earlier or is it based off babies measurements?

1 doctor answer1 doctor weighed in
Dr. Marvin Ott
Emergency Medicine 22 years experience
Measurements: Your first due date was likely based on your last period or some very early ultrasound measurements. Both are fairly inaccurate. As you progressed, your due date was refined based on later measurements. Remember, though, doctors (like anyone) are not great at predicting the future. Only about 5% of babies are born on their due date. Hope this helps!
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Nov 14, 2015


Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.