Congratulations! I just saw your post and wanted to add some info. Just like threexli said, many women experience failure to progress and it does not matter wether it is your first , second or third delivery.
When my children were born, they did not do amnio's unless you were over 35. They were still relatively new, and as the gene was only recently discovered at the time it wouldn't have made a difference in my situation.
My first child was stillborn at 42 weeks. I never had labor what so ever.
My 2nd son was induced (because of the stillbirth) and I did not progress past 8 cm with pitocin for over 32 hrs. My 3rd child was a girl, and my labor started naturally at 38 weeks and lasted less than 6 hrs. My last child was induced at 39 weeks and labor went on and on for over 40 hrs before they did a section. (By the way he also has the most scaling and is the more severe xli of my sons. My oldest only has symptoms on his scalp and neck.) We recently had it confirmed that it was indeed x-linked and not vulgaris as originally diagnosed.
Any way, my point is not to scare you, you already have heard from the most knowledgable on the boards. I just wanted to relate my experience, so that you can relate all this to your OB/GYN. You may have a normal labor, but with this you can't really tell. But stress to your Dr. that you should not go past 40 wks.
The ichtyosis it's self is a managable condition, and you will have a beautiful child. You may have already seen this article from e-medicine, but it's definatly worth having the OB put it in your records. http://www.emedicine.com/derm/topic191.htm
I have even included this, with the fetal mortality paragraph highlighted, in my daughters medical records even though she is only 13. And my sons will all be made aware of this, so there daughters will know.
You are very lucky to have found not only this forum, with all the wonderfull people who have so much support and information to give, at such a time in your life.
Knowledge is power! When I first suggested x-linked to our family derm. he just said "Humn, maybe" and that ws that. If I hadn't found this site, we still wouldn't have had answers.
Good Luck and again Congrats!