I am 38+5 with my first baby. My BMI was 37 at the start of my pregnancy. The worst thing, honestly, has been the shame I have been made to feel by the midwives - only in the community, though, the hospital midwives are lovely! I was told at my booking appointment that I should've been taking 5mg of folic acid daily, but I was already 10 weeks pregnant at that point and I knew from my own reading that the baby's neural tube had probably already closed. I was really freaked out and the midwife refused to provide any reassurance. That was really hard! So if your BMI is over 35, it's worth knowing that the official advice is to take 5mg of folic acid, although I didn't and I'm sure lots of other women don't either, because it's quite easy to miss the recommendation. I thought I had read the NHS advice online quite carefully and I missed it.
I was told by my original midwife that there was no chance at all that I'd be "allowed" to give birth at the birth centre. I was put on an obstetrician led pathway, because of my BMI (but I also have hypothyroidism, so this may have been a factor). By chance, I had a different midwife for one of my appointments about half way through my pregnancy and she told me that I did have a degree of choice and arranged for me to meet with the consultant midwife at the hospital, who agreed that I could use the birth centre if I wanted to. She explained that the only real risk in my pregnancy (given that I have been well) is shoulder dystocia (when the baby's shoulders get wedged during birth) and reassured me that they could get me to an obstetrician very quickly if need be. She also said that there is some evidence that you are less likely to have shoulder dissociate to begin with if you are in the birth centre because you are more mobile. So I'm really hoping that, providing I don't suddenly develop high BP or need induction, I'll be able to give birth at the birth centre. That's a long way of saying that you shouldn't feel like you have no choices just because you have high BMI!
I had terrible nausea weeks 6-16 ish, so I actually lost about 20lbs at the start of my pregnancy. As a result, I have only gained about 5lbs overall in the whole pregnancy so far. The sickness was awful but I am glad I haven't gained much weight. I've had a lot of back pain recently and I do wonder if that's because I started off heavier, but then lots of women with "normal" BMIs get back pain in late pregnancy too.
My GTT and every other test I've had in pregnancy has been totally normal. I had an extra growth scan at 36 weeks and the baby is absolutely at the 50th centile for everything. I didn't plan the pregnancy and probably would've wanted to lose some weight if I had been intending to get pregnant but I've been so pleasantly surprised by my body and how well it has coped. So don't worry at all - you'll be ok x