Anyone get an amnio for size discrepancy in twins?

(6 posts)(6 voices)
  1. I am 20w5d pg with fraternal twin girls. We've had 2 sonos in the past week (one with OB, the other with a Peri) and baby B is measuring small. The size difference appears to be 2-3oz and the Peri suggested an amnio. I've ready many accounts of size discrepancy in twins but not much talk about amnio to achieve a diagnosis as to the cause. We are conflicted and seeking a 2nd opinion from another Peri.

    Has anyone been asked to consider an amnio for size discrepancy in their twins? Did you go through with it? What was the outcome if you wish to share?

    Thanks ladies!

  2. I am 33 weeks with twins and at about 28 weeks the Dr noted about a 6 oz differece in their weights, The Dr actually measured again for its all an estimated based on how the tech measures and he came up with about the same; but since they are fraternal he just stated it was likely due to genetics and put that in his notes with no mention of any further tests. I think 2-3 oz is not a lot of difference and weights estimates based on measurements has that much error anyway. Now the twins weigh 4/4; 3/15. I would definately ask why and get a second opinon before any such test.

  3. At 18 weeks our g/b twins measured about 2 oz different, since there is a margin of error then maybe the discrepancy isn't as big as they think? I agree with simba in that I would get a second opinion before doing an amnio to check for anything further.

    When is your next appt for them to be measured? I assume soon if he was concerned enough to suggest an amnio?

    Best -


  4. I guess the amnio would be to check for any chromosomal issues that may cause a smaller size. Yes, thats right, some kids are just smaller, and they are just fine. GL with whatever you decide!

  5. loss mentioned

    at both seven and nine weeks, my second twin measured one week smaller than the first twin. based on the high-risk OB's experience, we were advised that there was a 25% chance that the reason it was not developing correctly was a chromosomal problem. so we hoped for the other 75% chance that they were just fraternal, and different in size.

    the doctors recommended diagnostic testing to be sure, so we agreed to perform a cvs (similar to amnio, but the sample is taken from the outside of the placenta between ten and thirteen weeks).

    at twelve weeks, just as we were getting ready for the test, we discovered that we lost the second twin, and the doctors concluded that it was most likely because of a chromosomal defect.

    because we opted for invasive diagnostics, we didn't pay much attention to the nasal bone and nuchal fold ultrasound evaluations, which would normally be the first step before deciding to do an cvs or amnio i think. have you done any other blood or u/s tests related to screen for chromosomal problems?

    i hope whatever decision you make will give you peace of mind. good luck.

  6. My twins had a 20-30% size difference and they are of my twins had a 2 vessel cord and actually both had sub-optimal umbilical cord insertions. my twin b was born in the 3rd (yes, that's right, 3rd) percentile. there are lots of reasons for one baby measuring smaller than the other.

    the best thing to do is to look at each twin on their own curve rather than compared to one another (hard, i know). they say that all is good as long as both twins are above the 10th percentile. i delivered at 34 weeks but the boys are doing amazing- meeting all their milestones and some even ahead of their actual age. small doesn't always mean something is wrong- although if it were me i would do an amnio to rule out any chromosomal issue- but i would understand if others felt differently.

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