The Birthplace Study continues to publish interesting analyses, this one about the birth risks associated with larger BMI (over 35 kg/m2).
https://obgyn.onlinelibrary.wiley.com/doi/abs/10.1111/1471-0528.12437
Multiparous women with BMIs over 35 appear to have a lower risk of adverse events than primiparous women with BMIs within the 18 to 25 range, and to generally have fewer problems associated with birthing their children than we may have believed. Of course, primiparous women generally have a lot of meddling with their labours and births and only a minority have straightforward births without interventions, so the comparison is not without its problems. However the data does show that higher BMI in women who have given birth previously is probably being over-played as a "risk" factor.
Perhaps consultant midwives and Birth Centre managers in the UK will be able to get the criteria for Birth Centre care altered to reflect this evidence.
While I am on the subject of bigger mothers, here is a link (will also post in useful links section) to the blog of The Well-Rounded Mama and her previous excellent website. Lots of information here and a positive approach to birth and mothering with a well-rounded body!
https://wellroundedmama.blogspot.co.uk/p/about-this-blog.html
http://www.plus-size-pregnancy.org/firstindex.html