Pretty much as others have said.
Like you, I'd planned on losing as much weight as possible.before getting pregnant. I'd been told though that being 35, being.om the pill for 7 years previous AND being so overweight that this was going to take a long time (at 35, this is not on my side) so we weren't trying, as such, but didn't take precautions.
I fell pregnant immediately. I then had a miscarriage at 9 weeks. I don't think this was necessarily weight related as I believe the odds with 1st pregnancy is 30% end in miscarriage.
Once I had allowed 1 period after this, I fell pregnant straight away and had my girl in June. Because of the 1st pregnancy I knew about the folic acid so I started taking the extra folic acid straight away. I've never had any issues with blood pressure (usually low side of normal) I was surprised how much higher it was in pregnancy although they always said it was high normal. I do think they were using the wrong cuff half the time but it never flagged as an issue. I had the gestational diabetes test which was fine. If you're due to go into work after having it, consider taking the afternoon off. I felt sick as a dog after and was glad I had the afternoon as holiday.
They did sometimes have issues with getting all of her measurements at scans, I did have to."lift my stomach", yes that made me.want to die a little but it is what it is.
I know they say you shouldn't diet while pregnant but I got conflicting feedback from consultant who was ecstatic when I'd lost 1lb over course of 2 mths, I'd not been trying to, just trying to gain minimum amount. The dietician I saw was ok with the 1lb off but reiterated that I shouldn't be losing weight, even at my size, but should keep weight gain in check. I definitely could have lost weight by just eating healthily if they'd made it clear that that was ok.
They strongly advised getting the epidural early due to possible issues siting it. If I'd needed a c section (higher risk of intervention) but had tried to do without, this could have caused delays or meant they had to give me a general. I got the epidural pretty much straight away after being taken to labour ward at 4cms.
Btw, my waters broke before contractions started. The machine they used to check on baby but is also supposed to detect contractions. First time there was nothing to detect but they used it a further 2 times and then during labour, with me telling them i was having contractions and it wasnt detecting anything. I think they initially put it down to being a mental first timer so don't forget to tell them stuff like that. I didn't know they were trying to measure that stuff so they were prepping to induce me on basis of no contractions.
They did have problems but that could have been partially to do with the rookie trying to do it. She gave up and the anaesthetist took over and finished it up straight away. After that I was text book. Dilated as expected, in the time expected, natural birth, no intervention, 3 stitches for 2nd degree tear.
I don't believe in this whole health at any size thing that's bouncing around the internet. I was and still am more overweight than anyone needs to be and I am working on that. However, I think there are varying degrees of health with overweight people and if you're fat because you're eating too much and exercising too little, but it's not constant chocolate, take away or fried food etc you should hopefully have a better time of it.
Sorry this was so long but I hope this is useful.
Hopefully I will be down to a good weight for number 2 and I can try for the fancy birthing centre rather than labour ward next time.