irregular yolk sac

  I am 31 yrs old and am 8 wks pregnant. I have had 2 miscarriages in the last 11 months, one at 11 weeks was a blighted ovum and the second one at 8 weeks,five hours after an u/s with a beating heart.  I just went to the dr.(a different practice - more aggressive) on 2/19 and again we have a beating heart, but the doctor said my yolk sac was shaped irregularly and had some echos in it.  She said she had never really seen anything like this before and didn't really know what it means.  I have been on progestrone 300mg/day for about 11 days.  I read on the internet that 80% of pregnancies with irregular yolk sac end in miscarriage.  Is this true?  Please give me any insight into this problem.  Also, what causes this anomaly?  Thank you for any help.

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Dear Leigh:
I can not give an answer why a yolk sac has an irregular shape. This is a worrisome sign to sonography physicians who support the internet statistic that you cite: a large proportion of pregnancies with this observation do poorly. Medicine is very bad at answering why: much of our information is observations and correlations made over time.
The good news is that this observation proves to be a "red herring" in some patients and we cannot predict who will be in each group.
Keywords: irregular yolk sac
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