OB Appt today, measuring small?

[Inkedstar]

I'm getting concurrent care through this pregnancy so this week was my NP appt. She palpated and all felt good, my urine tests turned out fine (no signs of UTI/kidney infection as suspected) and then the doppler was whipped out.

She tried finding a heartbeat but couldn't (but could hear baby moving presumably away from the doppler).

I wasn't terribly worried (when I saw an OB for the possib. UTI she found the HB on doppler at 150 bpm), but the NP wanted to take a peak w/the U/S. There was baby, being quite active  and then the HB was found at 148 bpm.

She did a quick head to rear measurement which estimated me closer to 14 weeks (according to my dates I'm about 16 weeks).

I'm pretty sure of my dates but it just got me a little worried (even though the NP said all looks well). Has anyone else measured small in the 2nd trimester?

I have my MW appt next week (my 1st, FINALLY) so i'll be interested to hear what she discovers w/her palpation skills.

After that the 20 wk U/S is sched. in mid Feb. I'm not too keen on heavy amounts of U/S but I must say I can't wait for the 20 wk one.  We won't be finding out the sex but I just love that sneak peak you get.

[meander]

At my last appt, my OB told me that crown-rump length is only accurate until around 13-14 weeks, and after that they tend to use other measurements. (Don't know what, because I am not there yet!) Maybe it was the best view she could get in a quick check, especially if baby was wriggly, but it would be somewhat less accurate for you at 16w. You can get off measurements even before 14w if baby is curled up tightly, turned funny, etc.

If she had been worried, I would think she would have done some more measurements to be sure.

[MarineWife]

U/S measurements are very subjective and based on averages so I wouldn't worry as long as the heartbeat was good.

Also, being sure of your dates depends on what dates you are talking about. If you were charting your BBT and know when you had a clear and sustained thermal shift and, therefore, can pinpoint O, then you can be sure of your dates. Count O day as 2 weeks and count ahead. Does that put you at 16 weeks? However, if you are going by lmp, that is very unreliable for dating a pregnancy.

[Inkedstar]

Thanks MW! I'm going by my LMP date because I don't chart. I was about to start (my new yrs resolution was to chart) but then I got pregnant.

I'm feeling better about the u/s measurement. I think I may need to limit my concurrent care and rely more on my MW. I'm getting alot more anxiety from the OB side of things.

 

Originally Posted by MarineWife 

U/S measurements are very subjective and based on averages so I wouldn't worry as long as the heartbeat was good.

Also, being sure of your dates depends on what dates you are talking about. If you were charting your BBT and know when you had a clear and sustained thermal shift and, therefore, can pinpoint O, then you can be sure of your dates. Count O day as 2 weeks and count ahead. Does that put you at 16 weeks? However, if you are going by lmp, that is very unreliable for dating a pregnancy.

[MarineWife]

In that case, I'd be much more confident going by the u/s measurements, except for what the PP said about how crown to rump length is inaccurate at this point. With a later u/s, you should get a much better idea of how far along you actually are. Keep in mind, though, that even those can be off by a week or more. You'll need to be careful about that if you get to a point where someone starts pressuring you to be induced and you aren't as far along as they think.

[Asheya]

Crown-rump length measurements are most accurate between 8-12 weeks (accurate to + or - 5 days), and even more accurate when someone very skilled in those types of measurements is doing the measuring! At your 20 week ultrasound any measurements will be accurate to + or - 2 weeks. For your own peace of mind, you might prefer to take the latest possible date as 40 weeks gestation, keeping in mind that you have an 85% chance of actually giving birth in your birth 'month (the 2.5 weeks on either side of the day you are supposedly 40 weeks) and only a 4% chance of giving birth on your due 'date,' even if you know the exact day you conceived.

As for measuring small, it would mostly be a concern if you were consistently measuring small (your midwife will measure your fundal height with a measuring tape), and if you are not a small to medium sized woman. Small women tend to have smaller babies (although not always!) as there is only so much room inside for baby to grow.

Hope that helps!