Can Retroverted Uterus Cause Discrepancies?

Jane Foley's picture

QUESTION

Dear Ms. Ultrasound,
I have a tilted uterus. Most likely this is due to genetics as my mom and sister both have the same thing.

I was wondering if it may have caused some problems with dating my pregnancy in the first trimester. I had a scan early on that showed me to be 5 weeks (no baby, just sac). I had an extremely light period that started on June 3rd so they calculated this as my LMP. I was on birth control and was 10 days late getting this 'period' but I just ignored it and said it must be because of stress levels. I also got a positive test before this but it was very very faint and so I just decided I must have been seeing things or it was an evaporation line.

Could my ultrasound at 5 weeks been wrong due to my retroverted uterus? Would it make things harder to see? It was a trans vaginal ultrasound. Now my fundal height is measuring about 3 weeks ahead of what I'm supposed to be. I had a 3D ultrasound and the tech said the baby looked to be older than I said he was. This is why I am wondering if my dates were actually calculated wrong, which would put me a lot closer to my due date than originally thought.

Should I ask for another ultrasound? Will they even consider this due to the other ultrasounds I had measuring fairly correctly (only a little ahead)?

ANSWER

Hello
A retroverted or 'tilted' uterus in no way interferes with the accuracy of an ultrasound.
The vaginal probe is turned 180 degrees and voila! A baby!

The first trimester ultrasound and the dates these early exams provide are the most accurate. Once you get in the mid, second trimester and the third trimester, the dating is much less accurate.

Unless your second trimester ultrasound shows a three to four plus week discrepancy I would not worry. The early dating you received is the one you will stick with throughout the pregnancy.

With Regards,
-- Jane RDMS