Weird 20 week scan

[RobynNora]

Hello. I was hoping for some advice regarding my scan and due dates! I'm a first-timer so I may well be overthinking this!


I had my 20-week scan yesterday and very happy that all appeared well. However, my sonographer changed my due date by nearly a week. She didn't actually tell me that anything had changed but just amended the due date on my paperwork.

Both the midwife and nurse I saw afterwards mentioned the new date from my paperwork and were as confused as me as to why it had changed. Naturally, I Googled it back home, and learnt that 12-week scans are much more accurate and that dates don't tend to change at 20 weeks. My due date was already amended at my 12-week scan by nearly a week, so now the baby is measuring considerably ahead of the dates I'd tracked using my period! I suspect he's probably just a bit big, but it's bothering me that it might have been changed in error.

The sonographer forgot something else too and was a bit odd generally, so I wonder whether she might have been having an off day.

My question is - if she did make a mistake, does this even matter? And could it have implications in future for my pregnancy/baby?

Probably overthinking this! Thanks for reading :)

[Gerdticker]

Maybe have a chat with your midwife?

Generally I would say follow your instincts if things didn’t seem right, you don’t mention what was forgotten - was it something important?

I guess you could go for a private scan and ask them to independently date you. Although I think it’s generally recognised that the error margin For due dates Is about a week.

As I understand it, private sonographers generally also work for the NHS so they’ll be able to chat To you about anything that may have been missed or went wrong?

[sarahc336]

Mmm I didn't think they changed them at the 20 week scan it's the 12 week scan that dates you. I think I'd run this past the community midwife when you next speak to her/see her x

[TwinkleStars15]

I’d definitely follow this up, it’s very clear that your due date should not be changed at your 20 week scan and no matter what the measurements, your due date remains the same as the one given at your ‘dating scan’ (hence the name!)

[RobynNora]

Thanks to all three of you who answered. This is really helpful and I'll definitely follow up now without worrying about wasting anyone's time. MN is so excellent!

@Gerdticker to answer your question, she also forgot to let me know the sex, which I'd asked to know. Not a huge deal, as it's far more important baby is healthy, but made me think she might be a bit tired or distracted. Great idea on the private scan too - I'm glad to know that's an option.