Really? I had it measured every time I visited my midwife here in NZ from
about 20 weeks onwards.

I've also corresponded with NZ midwives who use it regularly, I think that a
tape measure that actually has a slightly more realistic scale than 1cm per
week originated there, because that is actually not very accurate for many
women, so there is some desire for a better way of figuring out when there
is a real concern, rather than automatically worrying when it's a certain
number of cm behind. (Incidently, I've had an IUGR baby who measured spot on
until 32 weeks, then no increase, therefore wasn't at the worry point of 4cm
behind until 36+ weeks, but there being a problem was clear at 34 weeks,
whereas my non IUGR baby was consistently 4cm behind, emphasising that
changes from week to week are probably more important than the absolute
value).

Anne