What Does My Ultrasound Scan Test Result Indicate?

Posted on Sat, 21 May 2016

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sat, 21 May 2016 Answered on

Fri, 24 Jun 2016 Last reviewed on

Question : Hi Doctor,

According to my wife LMP She is 31 weeks pregnant but according to ultrasound scan BPD shows 34 weeks ,so will it affect EDD? Her LMP is 9/10/ 2015.so wat would be her EDD??

Answered by Dr. Deepti Verma (24 minutes later)

Brief Answer:
Normal ultrasound error

Detailed Answer:
Hi dear,
I have gone through your question and understand your concerns.
By her LMP, her EDD is 16/7/2016.
Today, she is 31 weeks 6 days pregnant by her dates.
Ultrasound in third trimester can show variation in gestational age upto 3 weeks. It is normal to have a 34 weeks BPD in ultrasound at 31 weeks gestation.
The EDD is calculated by dates or her first trimester ultrasound.
It is never calculated by a third trimester ultrasound.
Hope you found the answer helpful.
Regards
Dr Deepti Verma
OBGYN

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar