I think Suga has summed it up well when she has said its a wonderful diagnostic tool which it is.

Obviously a dating scan is done to see the expected EDD so if an induction is neccessary for what ever reason or preterm labour you know the correct gestation of the baby. Although I must say this can be limited as women do bake their babies differently and my 36week baby was able to cope outside well where as another might not.

A 12-13week scan is generally done for the nuchal scan again another diagnostic tool to check for some abnormalities. It does given families the option to terminate if they want if a problem is identified. How many children do you see with downs syndrome these days? Not many compared to 50years ago or even 20years for that matter.

18week scan is obviously done to check the baby and placenta etc and identifies alot of abnormalities if any (although not all) basically to check the future wellbeing of both mum and bub.

Again growth scans further along also have their place in diagnosing IUGR, placental insufficency etc and a desision for early C/S or induction maybe neccessary to reduce the risk of fetal dimise in utero which these babies are at risk of. As well as scans to again check the placenta, fetal movement and any causes for reduced movements etc. A friend of mine had an emergency c/s at 32weeks due to IUGR Bub was only 800grams. Which is the size you would expect at 25-26weeks.

I think when offered alot of people jump at the opportunity or request them knowing they will see the baby again and forget they are there for diagnostic reasons not for maternal requests. I personally will probably take all the scans for diagnostic reasons. I want to know if my baby isn't growing accordingly, if there is a placental problem or other problem identified etc. I say bring on the scans for me and at the same time pray that all they find is a healthy looking mum and bub. And of course I do love a picture to take home if possible and not a nasty sonographer.