Really happy with the sizing and fit of the swimming costume. I bought the large (I think 16/18) and there’s plenty of room for going full term in the tummy area. I bought this at 22 weeks and fitting a size 18 trouser more or less. Breast size is accommodating too for varying sizes - I was a 38B/C and with usual pregnancy growth the fit is great. The fabric is soft and stretchy and will serve the length of the pregnancy. Super happy.