Is Early Ultrasound Accurate?

Cynthia Flynn's picture
Experts: 

QUESTION

Dear Midwife,
I had a ultrasound 2 days ago and it said I was six weeks instead of ten weeks as I originally thought. I have irregular periods. How accurate is this result?

My first baby was diagnosed as not thriving in the womb at close to my 40-week mark and was induced because the ultrasound said my baby was only 3 pounds but she was born at delivery weighing at 6 pounds.

Please tell me, should I trust this or will I have to go through more testing to get an accurate due date?

ANSWER

A six-week ultrasound is almost always accurate, assuming that this is a viable pregnancy. If they were able to see a heartbeat (not always possible this early), that would be more confirmation that everything is ok.

The only way you could be ten weeks along and have this ultrasound is if you were about to miscarry.

Estimates of weight at term are notoriously off, as you have found out. Personally, I trust my hands much more than I trust an ultrasound.

Good luck with your pregnancy!
-- Cynthia, CNM