When to start wearing maternity clothes, and what to buy first

The bra goes first, usually. It's tight round the band by teatime, the cups feel like they belong to someone else, and you're only nine weeks.

The jeans hold out longer. Then one afternoon the button is digging in after lunch, and you spend the meeting with it quietly undone under your jumper.

Which is why there's no one week for maternity clothes. There's a moment, and it comes at different times for your top half and your bottom half.

• The NHS says early signs usually start at around 4 to 6 weeks, and breasts that get larger and tender are one of them.
• The NHS week by week guide says the bump won't start showing until the second trimester, which begins at 13 weeks.
• From 28 weeks, the NHS advice is to go to sleep on your side. That's the latest point a pregnancy pillow earns its place.

When should you start wearing maternity clothes?

When your own clothes start telling you. The usual signs:

• The waistband of your jeans or leggings sits under the bump and rolls or digs in by lunchtime.
• Your bra leaves a red line round your ribs, or the cups spill over.
• Your jeans only close with a hair bobble through the buttonhole.
• You're hitching your leggings up every time you stand.

For the bottom half, that's usually somewhere in the second trimester. The NHS guide says your bump won't start showing until then, and for most people that's when the waistband gives up too.

Bloating can get there first. At 8 weeks the NHS says you might be feeling bloated a few weeks before you look pregnant, so tight jeans at 10 weeks aren't a reason to buy maternity jeans. Bloat versus bump is in our post on when you start showing.

The top half comes earlier. Larger, tender breasts are on the NHS list of early signs, and by 12 weeks its guide says your breasts are probably getting bigger. That's why a bra is often the first maternity thing anyone buys, weeks before leggings.

One opinion, strongly held: don't buy ahead. A bra bought at 8 weeks for the size you think you'll be at 30 is the wrong bra twice. Buy for the body you've got this month.

If you're not telling work yet, the same soft pieces go under a looser top, and our post on hiding a bump has the outfits. Earlier than all this? Start with the first trimester to do list; clothes come later.

Maternity clothes by trimester

Typical weeks, not a rule. If your jeans gave up at 11 weeks, nothing's wrong; you're just early.

What maternity clothes do you need first?

Three things, and the first one isn't about the bump at all.

A bra that fits now

This is the one most people put off and then wish they hadn't. The NHS lists pregnancy among the causes of breast pain, and its advice for easing breast pain is a properly fitted bra during the day and a soft bra to sleep in.

So get measured. A fitting in a shop is easiest; then match your band and cup to our size guide. Do it again in the second trimester, because by 18 weeks the NHS says your breasts may have gone up a size, particularly if it's your first pregnancy.

Soft stretch, no underwire and a clip for feeding means the same bra carries on after the birth. The sleep bra and the firmer Support+ are in our maternity underwear guide.

One reviewer, a 36F, wrote: "Not a fan of underwire either so nice to find something comfortable and supportive".

One pair of over the bump leggings

When the waistband sits under the bump and you're hitching all day, buy one pair. The panel comes up and over the bump, so there's nothing underneath to roll down. It keeps stretching through the third trimester and stays comfortable while your body settles after the birth, so one pair does the lot.

Over or under the bump, which fabric, and why ours run small are all in our maternity leggings guide. The short version: go by your usual dress size, and up one for your legs, not for the bump.

A support band for the weeks in between

There's a stretch, often somewhere between 12 and 20 weeks, when the jeans are on a bobble, the bump's half there and nothing you own sits right. Our band vs belt post calls that the band's best window.

The BABYGO® Pregnancy Support Band is one wide velcro panel that supports under your bump and across your lower back. It goes on in seconds and lies flat under a top. One Size fits 70 to 140cm round your lower tummy, under the bump, and the XL goes to 160cm for a bigger bump or twins.

It won't fix back or pelvic pain, and the product page says so. If something actually hurts, you want a belt, not a band. Take it off when you're resting.

What maternity clothes can wait?

All useful, none urgent. Wait for the reason, then buy.

A support belt, if your back or pelvis complains

A belt sits under the bump and lifts it, taking weight off your lower back and pelvis. It's for pain, usually from about 20 weeks. If nothing hurts, you don't need one. If the pain is bad, the NHS says to talk to your GP or midwife. Our support belt guide has the sizes and when to wear one.

A pregnancy pillow, when side sleeping gets hard

Buy it the week you stop getting comfortable on your side, not before. The NHS says that from 28 weeks it's safest to go to sleep on your side. Plenty of people start earlier, around 20 weeks, once the bump or the hips keep them awake. The shapes are compared in our pregnancy pillow guide.

Maternity knickers, when yours start to roll

Your own knickers will do until they leave a red line or roll under the bump, which for most people is somewhere between 10 and 16 weeks. Then it's over or under the bump in your pre-pregnancy size, and our maternity underwear guide has which cut suits what.

Knickers can't come back once the pack's open, for hygiene reasons, so check the size guide rather than buying two sizes to try.

Night feeding kit, the sleep bra included, belongs on the hospital bag list rather than the 12 week shop.

Can you just buy bigger clothes instead?

For some things, yes, and that's where most of the saving is. Plenty of your own wardrobe already works with a bump, or will a size up:

• Stretchy jersey and wrap dresses. No maternity version needed.
• Long cardigans and open shirts, worn over the bump rather than buttoned across it.
• T-shirts a size up, the one place sizing up works. Or knot your own at the side, above the bump.
• Big jumpers, including your partner's.

Sizing up doesn't work for anything that has to fit close. Leggings or jeans a size bigger go baggy in the leg and still cut in at the waist. Bigger knickers tend not to stay put. And a bigger underwire bra still has a wire in it.

For the jeans, there's the hair bobble trick, and it's good for a few weeks. Loop a bobble round the button, thread the other end through the buttonhole, then pull it back over the button. The jeans stay up with the button undone, and a long top covers the gap.

It's a bridge, not a plan. Once the zip itself starts pressing on the bump, it's time for leggings.

When you do buy maternity pieces, buy your pre-pregnancy dress size. They're already cut for a bump.

How many maternity clothes do you actually need?

A capsule, not a wardrobe. For most people this covers the second trimester and a good way into the third:

• Two bras, one on and one in the wash
• Two pairs of over the bump leggings
• A support band, if you'd like light support
• A few pairs of maternity knickers, once yours start rolling
• Your own dresses, cardigans and big tops

That's it. Maternity clothes aren't cheap and I won't pretend they are. But this is a handful of things that last from now until after the birth, not a new wardrobe you're done with in a few months.

Questions we get asked

Should I buy maternity clothes?

Some, but fewer than the shops would like. Most of what gets you through is stretch you already own. The things worth buying are the ones that have to fit close: the bra, the leggings and, later, the knickers.

Do you need maternity clothes in the first trimester?

Usually just a bra. Larger, tender breasts are one of the early signs the NHS lists, while the bump itself doesn't tend to show until the second trimester.

What size maternity clothes should I buy?

Your pre-pregnancy dress size, because maternity cuts already allow for the bump. If you're between two sizes in leggings, go up one for your legs. Bras are different: buy the size you are now.

How do you measure for a maternity bra?

Get fitted in a shop if you can, then match your band and cup on our size guide, which runs from a 28 to a 42 band and A to G cups. Between two of our sizes, take the smaller; the knit has plenty of stretch. Measure again if the band starts to dig in.

How long do you wear maternity clothes after giving birth?

There's no set time. The leggings and the bra are the two that carry on, the leggings because the panel stays comfortable while your body settles, the bra because it's made for feeding. If you've had a c-section, what to wear after a c-section covers the first weeks.

If the waistband's already rolling, start with the maternity leggings and the maternity bras, and give the bra size guide a minute before you order.