Gestational sac measuring behind crl of fetus

knottied15df4d40608577e

Hi ladies,
Went for my first dating ultrasound yesterday. I’m measuring about 6 days behind based on LMP. So I am around 6w5d but they also said they couldn’t date properly as CRL is less than 10mm. Doctor came in after ultrasound to say that MSD - CRL = 4.1mm. It’s supposed to be greater than 5mm so that baby has enough room to grow. She did reassure me that any other doctor “probably wouldn’t have brought [me] back for an 2nd ultrasound” but she “wants to be sure” sac grows and is above 5mm difference. She mentioned the cut off usually being 4mm. So I left feeling reassured Leaving the ultrasound clinic but of course google changed all that. Just looking for other similar stories and how it turned out 🙏

luckyduck42

Is it possible you ovulated a little later than expected? Hopefully they can get better measurements in a week or two!

(Also, please see the post about changing your username. We would love to be able to get to know you, and build connections and support, but it is hard when you have a generic knottie username.)

mamapajama25

Hi! I hope you got your second ultrasound and figured this out. Wanted to reassure you that it’s common if you ovulated late. I ovulated on day 31 (vs the average 14), so my LMP date is useless. My little nugget is healthy so far and has grown as expected through my LMP would have put me way behind. They should ignore that date and go with the gestational age after your next appt.