There are established normal levels of fluid for each week of pregnancy, so your levels will be compared with these. In general, an AFI of 5cm (2in) or less, or a deepest pocket measurement of less than 2cm (0.8in), is considered to be low (Nabhan and Abdelmoula 2008, RCOG 2002) .he amount of amniotic fluid increases as your pregnancy progresses. You start off with just a few millilitres, but will have between 800ml (1.4 pints) and 1,000ml (1.6 pints) by the time you're about 36 weeks pregnant (Carter 2012) .