Confident that your bra fits correctly? Don't forget that your size is likely to change over time. Here's when to double check that your bra still fits.

• When you lose or gain weight. If your dress size has changed (and even if it hasn't), don't forget about your bra size – it's even more sensitive to weight fluctuations. If you gain or lose more than 7lbs or so, follow our checklist.
• If your body shape changes. Even if your weight remains the same, your proportions can change – if you start a new gym routine, for example.
• During your monthly cycle. It's possible to gain a whole cup size when you're menstruating, and you might need a different bra for those days when your breasts are quite tender – you don't want to squeeze them into a too-small bra.
• When you're pregnant – and beyond. Your breasts will start to swell in the first weeks of pregnancy and then again when you start to breastfeed. When you stop breastfeeding, they'll change size yet again.
• As you lose muscle tone and elasticity in your skin – as you age, for example, or when you stop breastfeeding. You might need to try a different style of bra – a half cup, say, instead of a full cup if you have lost muscle tone in the upper half of the bust.
• If you start taking the pill or HRT. Any hormonal medication can have an effect on your bra size. If do you experience a change, it's likely to be that your breasts are bigger.

Even if none of the above applies to you, we still recommend checking your bra size every 12 months.
Women are often told to buy their maternity bras in the fourth month of pregnancy; instead, we recommend listening to your body and doing what is most comfortable for you. For example, your breasts might start to feel swollen well before the fourth month, so do be prepared to invest in a few new maternity bras to accommodate your changing shape as your pregnancy progresses. Generally, though, a maternity bra should fit you on the tightest hook when you buy it – you can loosen it, or even buy bra extenders – as you grow.
However many bras you need, comfort is always key. Your breast tissue is growing and will be very delicate, so underwired bras are best avoided if they haven’t been specifically designed for pregnant women. (Underwired maternity bras have a flexible wire that is longer than usual – this means that the bra is wider at the sides to avoid the underwire hitting your glands, which can cause mastitis.) What to look for? Comfortable, wide straps that don’t dig in, as well as a breathable fabric or one with a high cotton content to keep you cool.