CRL consistantly measuirng 1 week behind for both sacs (twins) - IVF

[alpbmp]

I am currently 9w/1d and here is my story:

IVF #1 - m/c, IVF #2 - bfn, IVF#3 - bfp (confirmed on 3/25 - 14dp3dt)

At my 5w/4d u/s the re was able to see 2 small sacs. At 6w/4d, both sacs were visable as was a h/b, but the sacs were measuring about a week behind. At 7w/4d, both sacs were visiable with a hpm of about 130, and again, both sacs were measuiring a week bihind.

I had mild spotting of dark brown blood at 7w/5d and went in for another u/s on 7w/6d; both babies were visible and h/bs were still at approximately 130 bpm. RE was able to detect a small blood clot behind sac B. He also said that sac B is small for the babie and that he did not feel confident that baby B would make it, but that baby A looked good.

At 8w/5d, babies were still measuirng a week behind with hb of about 167 bpm (sac B is still small).

My questions are (1) is this common for IVF or twin pgs to be a week behind in measurement (2) should they catch up or could they be consitantly 1 wwek behind for the entire pg and (3) My RE says that he is pleased with the consistant growth, but should I be worried that we are an increased risk of m/c because they are a week behind?

[mom2jake2001]

Hi,
Unfortunately I don't have any answers for you, but am in the same boat as you.  I went thru a 5 day FET on march 19th. Got my 1st scare this pg at 6w3d when I started bleeding. Had u/s done at that time and was dx'd with a SCH. Both babies measured 6w1d, and heart rates were 123 and 126.  The 2nd u/s we just had I was 8w5d and baby A is measuring 7w6d and baby B 8w0d.Their heartrates were strong and normal. I really hope someone answers your questions as mine are the same.  I would really like to compare notes with you and see if you have learned anything new since you posted this.  My hope is that it is just error that they talk about of +/-7.  Seems kinda weird that they are growing well from u/s to u/s and the other thing is what are the odds of them both being bad and lagging at the same rate??  Hope to hear something soon.  I won't be going for another u/s until may 18th.  

[tina1111]

Ditto to what peek said, plus with two they usually will measure smaller :)

[peekawho]

Once you see the heartbeats, your chance of miscarriage goes down dramatically.

Ultrasound measurements are not an exact science.  They usually coincide  within a week at your gestation--your RE should be the one you listen to.  Consistent growth and good heartrates are what you need to focus on.

Good luck!