While you know that your abdomen is going to expand, you probably haven't given a lot of thought to other areas of your body that are also likely to, ahem, grow.
Many women go up a whole cup size during pregnancy so it's important to get measured during each trimester to make sure you're wearing underwear that's right for you.
Most department stores offer a bra fitting service for free and will stock maternity underwear.
Comfort should be your main priority but that doesn't mean you need to invest in granny pants! Just try and stick to soft cotton underwear rather than anything too lacy.
Maternity knickers will generally have a higher waistband so that they come up just over your bump. Of course these aren't for everybody. If you're carrying high you might find that a hipster brief will work better for you.
Avoid push up bras and bras with lots of padding. As your breasts change throughout pregnancy these sorts of styles can become very constricting. Try cami tops and bras without underwire to stay feeling comfy.
Maternity tights are designed to come up and over your bump and will often have hidden support. Most women find that regular tights tend to roll and bunch underneath their bump so it's a good idea to look for tights with high waists and a thicker denier.
For more information on pregnancy health and advice go to www.nhs.uk/Start4Life