I've been meaning to post on this thread for a while,sorry for the delay!
I'm in south London, I'm not pregnant at the moment, but am T1 (nearly 30 years since dx), pumping for the last 8 years, and have a DD who is 5 and a DS who is 2. Both born by CS due to retinopathy complicating things. I'm also on the diabetes-support website, though haven't logged in for ages.
DD was delivered at 39+something weeks, DS at 31+3 (he's a surviving triplet). Both were BF for about a year.
They normally deliver at 38 weeks now because a diabetic placenta ages quicker than a non-D one, so 38 weeks is approx equivalent to 42 weeks IYSWIM. Insulin levels dropping in the 3rd trimester can be a sign that the placenta is failing, take it seriously and get checked out.
If you're planning to BF, be prepared to drop your insulin levels to about 75%ish of pre-pregnancy levels - often nobody warns you that BFing causes your sugars to drop through the floor. NEVER sit down to feed without jelly babies to hand, to go with your glass of water Certainly nobody told me, hence DH getting a call at about 3am on the 2nd night in hospital, saying "no need to worry, but we've moved your wife back upstairs...she had a hypo..."
Speaking of which, take lots of snacks into hospital with you - hospital food is dire, I carb counted one days menu after I had DS, there was a magnificent 75g carbs for the whole day.
If anyone's got any specific questions about T1 and babies, I'm happy to try and answer them we're TTC #3 currently, I'm getting very impatient with things!