Simple, empire-line dress and matching jacket in lined cotton or possibly linen. It may be hot so you'll want cool materials. Then a knockout hat and gloves.

Is it an outdoor event? Royalty present?

Lace gloves are always a good, safe bet unless you're shaking hands with royalty.

This one looks pretty formal but I like it (disclaimer - I'm not sure it looks so great on the pic with the model)

www.blossommotherandchild.com/sale/dresses/silk_taffeta_maternity_dress/32273/

www.mama-la-mode.com/shop/occasions/silk_jersey_long_sleeved_dress/RD/

Something like this? I know it's expensive but lots of shops have similar.

And how about a fascinator?

www.hatsnstuff.co.uk/

Oh, just realised you need shoulders covered... team with a bolero jacket?

www.seraphine.com/Scripts/prodView.asp?idproduct=1015&idcategory=36&SC1=28&SC2=36&title=Bustier+Dres s%2C+Elegant+Maternity+Wear ?

I actually think hats can be more difficult to find than a dress

I'd go for a cream / ivory - look in mother of the bride kind of dept. shops and then you can find gloves to match

www.hadleighhats.co.uk/collectionGallery.asp?style=hats how about number 143 with that Isabella dress?

PS hate my bum so would prefer something that didn't highlight quite how untoned it is....

Thanks for all the replies; it's hugely appreciated. So I am short (about 5 foot 2), blonde and will be about 20 weeks pregnant but second baby and look more. I'm sort of average size (between 8 and 10 when not pregnant). Legs are not my best feature but are good from knees down.

Really like the Isabella Oliver dress that sweetfall posted. Would that go with hat and gloves?

nice www.isabellaoliver.com/maternity-clothes/maternity-capsual-collection/Midi-Kimono-Wrap-Dress/D/30100 /P/2:100:2140/I/DR084

I would be inclined to go for a simple empire line / trapeze shape shift dress in a light crepe type fabric (won't crease too much). something like this maybe..?

I would think "What would Audrey do?"

If you can find a smart dark shift dress on a posh maternity site, then accessorize with a cloche-type cream hat and gloves, pearls maybe?

How pregnant are you?

Are you just bump pregnant or pregant all over

What size are you? Height? Colouring? Best features? How are your legs?

Thanks for the reply. No hat and gloves yet because I figure they need to fit around the dress. I don't know the answer to length/ shoulders but am assuming yes to shoulders covered and not too short.

Budget; flexible, I guess whatever I have to spend to get something appropriate. Couldn't see anything on Isabella Oliver - off to look at Crave now. (Really panicky because have never done the hat and gloves thing and don't know how I will know what kind of dress goes with this...)

Do you have hat and gloves already? What's your budget like? Are there rules about skirt length or whether shoulders are covered?

I'd be inclined to look at Isabella Oliver or Crave.

I have to attend an event later this month with DH's work for which the dress code is hat and tails for men and hat and gloves for women (guidelines say something like 'along the lines of Ascot' but not sure of exact wording as I don't have invitation here). I am pregnant. Is this asking the impossible? Where on earth can I find a smart, smart dress which I can wear with gloves and hat and not look a complete idiot. Can anyone give me any clues please?