First US - Dating Question/Reassurance

[bev81]

Hi everyone! Just had first US today at what I thought was 6w5d (based on LMP of 8/17). Pretty sure my O date was 9/5 based on temp/LH/first positive HCG test (vvvFL 9/14) which would put me at 6w0d. We saw gest sack, yolk sack, fetal pole, and showed “coloration” of cardiac activity but said it was too small to measure heartbeat. Based on the length of fetal pole, measuring 5w5d. Trying to stay positive but would love any feedback from anyone who has been in this situation either way.

Is it ok to be measuring a couple of days behind?

Does “cardiac activity” (colored movement) mean anything?

I go back in 8 days so should be definitive then.

 

[cfranco]

@bev81 OB sonographer. If you should be 6w0d by your ovulation, then what you are describing is completely normal. The very first signs of a fetal pole is at 6w0d. Very small and sometimes difficult to measure HR. Color flow proves the flicker is there, since it wasn’t able to be proven by measurement.

 

[bev81]

@cfranco Thank you! Really appreciate the reassurance. Guess that I should have oriented my dating expectations to ovulation vs LMP!

 

[jprice63]

@bev81 Since my ovulation never happens on Day 14 (which would make an LMP and ovulation-based EDD match completely), I always track the pregnancy in my mind according to my ovulation date. With this last pregnancy, I actually decided to give my provider an LMP date that was just my ovulation date minus 14 days. Your baby measuring just 2 days off from your ovulation date is completely fine. You didn't mention whether you did temping to confirm ovulation, but if you're like me and only used strips, then actually your ovulation could theoretically have happened a day before or after you assume it did, which makes your scenario even more hopeful. Bottom line: what you're seeing so far appears promising. Hope for more good news for you in the future!

 

[bev81]

@jprice63 This is so smart… I was actually wondering why my provider had me book a first U.S. inside of 7 weeks anyways because last time I’m sure I was closer to 8. My OBs office called me today and was concerned based on LMP then when I told them ovulation date they said it was likely fine and just too early.

 

[jprice63]

@bev81 Yeah it’s kinda hard to come to these providers as a type-A person who tracks everything because all their algorithms seem to be built on some average patient who barely kept track of her periods. When you start off telling them your ovulation date, they still ask for your maybe-irrelevant LMP because that’s what the little box on your health records wants them to record, so eventually I decided it makes more sense to infantilize them by just making up an “ovulation-adjusted” LMP and going with that

 

[cfranco]

@bev81 Yea, LMP gives an idea of how far along you are. But being that women ovulate anywhere between day 10 to day 20, this can vary a dating scan up to 10 days… sometimes more!

 

[algernon22]

@bev81 LMP only works well if you have textbook ovulation/periods. Based on what you’ve said about ovulation, 2 days off is absolutely nothing. Mine was 3 days ahead at 7w, which didn’t align with my ovulation/HPTs at all. Just at that size they are so tiny, the slightest difference can add or subtract a few days. Doesn’t look like you have anything to worry about! From what I’ve seen, +- 3-5 days (depending on provider) is completely acceptable range.

 

[josephjurg]

@bev81 Cardiac activity means that there is a "heartbeat" (its not a heart yet but its the equivalent) but they just werent able to measure it yet which can happen if the fetal pole is just beginning. Very nornal for 6 weeks.

 

[bev81]

Wanted to share an update for future readers, just left my US follow up (8 days after first) with good news. Dated 7+2 (spot on with expected O, and 2 days past first dating measurement) and saw heartbeat. Turns out the first one was just too early based on LMP.

 

[bev81]

In case anyone finds this post and wants reassurance or positive thoughts - had a healthy baby girl 7 weeks ago!