Lucy Flynn, BABYGO® team
Somewhere around 14 weeks your usual knickers start leaving a red line across your hips by lunchtime, or rolling down under the bump the second you sit. The band of your bra has started to dig in. Nothing fits wrong exactly. It's just that none of it was made for this.
This is what to wear instead, what the NHS actually says about underwear in pregnancy (very little, and all of it about thrush), and how to get the sizes right first time.
Short version: over the bump or under the bump knickers in your usual size, a soft wire free bra you can feed in later, and the size guide before you order.
Quick answer: Yes, wear underwear in pregnancy, whatever's comfortable. The NHS's one rule is loose cotton underwear to help prevent thrush. Swap to maternity knickers when your usual pairs leave marks or roll, usually 10 to 16 weeks: under the bump if you run hot, over the bump for support later on, in your pre-pregnancy size. A soft wire free bra in your current size does pregnancy, feeding and nights.
Key facts
- More discharge in pregnancy is normal, says the NHS. Healthy discharge is thin, clear or milky white, and shouldn't smell unpleasant (NHS, vaginal discharge in pregnancy).
- Thrush is more common in pregnancy, especially in the third trimester, and the NHS says loose cotton underwear helps prevent it (NHS, thrush in pregnancy).
- BABYGO® maternity knickers come over the bump or under the bump, in sizes S to XL and packs of 1, 2, 3 or 5, and you order your pre-pregnancy size.
- BABYGO® bras: the Maternity Bra runs S to XL and the Support+ runs S to XXXL, both wire free with nursing access, ordered in your current size.
- Leaking a little when you cough or sneeze is common in pregnancy. The NHS says every pregnant woman should do pelvic floor exercises, 3 sets of 8 squeezes a day (NHS, exercise in pregnancy).
Should you wear underwear during pregnancy?
Yes, and wear whatever's comfortable. There's no NHS advice to go without, and no advice to wear anything in particular except one line: loose cotton underwear can help prevent thrush, and so can skipping perfumed soap and bath products.
What changes is your body, not the rules. There's more discharge than before, which the NHS says is normal and is there to stop infections travelling up to the womb. Your hips widen before the bump shows. A sneeze can leak a little, which the NHS calls stress incontinence and says is common and nothing to be embarrassed about.
Ordinary knickers cope with none of that well. Maternity ones are cut for it, and the good ones have a proper gusset for the leaks and the discharge so you're not living in liners.
Call your midwife if discharge smells unpleasant or strange, is green or yellow, or you're itchy, sore or it hurts to wee. Those are the NHS's signs of an infection, and thrush in pregnancy is easily treated once someone's looked.
When should I switch to maternity knickers?
Usually somewhere between 10 and 16 weeks, when your usual underwear starts to feel tight at the waist or leave marks. There's no fixed week. The signal is discomfort, not a date.
What you're buying is stretch that goes the right way. Ours are a soft Tencel™ modal blend (71% Tencel™ modal, 22% nylon, 7% elastane) with four-way stretch, so one set generally covers the rest of pregnancy without being replaced each trimester.
They have no tags, hooks or hard seams to press when you're side sleeping, an anti leak gusset that dries quickly (triple layered on the over the bump pair), and they wash at 30 degrees.
The old version of this post told you to size up at least one size. That's wrong for maternity knickers, and it's the mistake we see most. Order your pre-pregnancy size: the panel is designed to grow with the bump, and a bigger pair mostly means a waistband that won't stay put.
Over the bump or under the bump maternity knickers?
Neither is better. Plenty of people buy one of each and wear whichever suits the day. The difference is where the waistband sits.
| Which pair | Under the bump | Over the bump |
|---|---|---|
| Where it sits | Below the bump, against your hips, low profile | Comes up and across the bump, so nothing rolls down as you move |
| Best for | Earlier pregnancy, warm weather, anyone who runs hot | Later pregnancy, when an under bump band has less to sit against and starts to slip |
| Support | Light | Gentle all round support and a smoother line under clothes |
| Sleeping | Fine | Plenty of people wear them around the clock in the third trimester |
| Size to order | Your pre-pregnancy size; between sizes, take the larger | Your pre-pregnancy size; carrying twins, take the next size up |
| Packs | 1, 2, 3 or 5 | 1, 2, 3 or 5 |
| Size guide | Maternity knickers size guide | Over the bump size guide |
If I had to pick one pair for the whole nine months, it's over the bump. If it's July and you're 20 weeks, it's under the bump, and the under the bump pair is the same fabric and the same packs.
BABYGO® Over the Bump Knickers
The pair for later pregnancy: the panel comes up and over, so nothing rolls under the bump. Sizes S to XL in your pre-pregnancy size, packs of 1, 2, 3 or 5, soft Tencel™ modal with a triple layered anti leak gusset.
Check the size guide before you order. With knickers you want the size right first time, and the guide takes a minute.
Want the rest of pregnancy week by week, for your dates? Tell us your due date and we'll send what to expect, what to do and what to sort each week, including when the waistbands stop fitting. 10% off when you're ready.
Do I need a maternity bra?
You need a bra that fits the body you've got this month, and most people's don't by the second trimester. A maternity bra is built for a size that keeps changing: soft, stretchy, wire free, and with nursing access so the same bra does feeding later. Sizing up your usual underwire is the other route, and it means buying again in eight weeks.
Wires are the thing to think about. Wires can press on breast tissue and milk ducts and contribute to blocked ducts while nursing, which is why our maternity, Support+ and sleep bras are all wire free.
The NHS has no rule on maternity bras, so this bit is ours and the customers'. One reviewer wrote: "It gives a comfortable shape without stiff padding or wires."
| Bra | Sizes | Packs | Best for | Between sizes |
|---|---|---|---|---|
| BABYGO® Maternity Bra | S to XL | 1, 2, 3 or 5 | Everyday and all day: soft, no wires, hooks or tags, a one handed nursing clip, holds a breast pad | Take the smaller; some find the fit generous |
| BABYGO® Support+ Maternity Bra | S to XXXL | 1 or 2 | A fuller bust, or when the soft bra doesn't lift enough: firmer support, still wire free, adjustable straps, nursing access | Take the larger; it runs slightly small |
| BABYGO® Nursing Sleep Bra | S to XL | 1, 2, 3 or 5 | Nights: soft crossover front, no clips, holds a breast pad in place | Take the larger |
| BABYGO® Nursing Sports Bra | M to XXL | 1 or 2 | Exercise, and days with a lot of carrying: the most supportive, with nursing access | Measure rather than assume |
Order your current size, not the one you expect to be. The stretch in the fabric covers a good deal of change without a new bra at every stage, and the size guides are on each product page.
BABYGO® Maternity Bra
The soft everyday one: no wires, hooks or tags, a nursing clip you can open one handed, in Tencel™ modal that washes at 30. Sizes S to XL in your current size, packs of 1, 2, 3 or 5.
Which cut suits what
The everyday and sleep bras have a crossover front, which sits under a lower neckline and is the one people nap in. The Support+ is a fuller cup with adjustable straps, for a day on your feet or a fuller bust. The sports bra is for exercise and for the days that feel like exercise.
If you're going to breastfeed or pump, all four open for it. If you're not, they're still the comfortable ones, and nothing about them says nursing from the outside.
Maternity knickers after the birth
You can keep wearing them. For the first weeks after the birth, though, a high waisted postpartum pair does a better job: it clears a c-section scar and holds a maternity pad more securely. Under the bump maternity knickers sit right on the hip and bikini line, which is exactly where you least want a seam after a caesarean.
What to wear after a c-section, day by day and week by week, is its own post. Until it's up, the postpartum knickers are the pair to pack for the hospital bag.
The bras carry straight on. The nursing clip is the point of them, and the sleep bra earns its keep at 3am.
Questions we get asked
What size maternity knickers should I order?
Your pre-pregnancy size, for both over the bump and under the bump. The stretch panel is made to grow with the bump, so ordering larger usually gets you a waistband that doesn't stay put. Two exceptions: if you're carrying twins, take the next size up in the over the bump pair, and if you're between sizes in the under the bump pair, take the larger. Sizes run S to XL.
Should I avoid underwire bras in pregnancy?
The NHS doesn't have a rule on it. Our reason for making the maternity, Support+ and sleep bras wire free is that wires can press on breast tissue and milk ducts and contribute to blocked ducts while nursing. If your underwire fits and you love it, that's your call; just get measured again as you change.
Can I sleep in a maternity bra?
Yes, and the sleep bra is the one designed for it: soft, no firm band, no clips, and it holds a breast pad in place overnight. Anything tight worn for twelve hours can contribute to blocked ducts, which is why it's deliberately soft. Between sizes, take the larger.
Are maternity bras the same as nursing bras?
Ours are both. Every bra above has nursing access built in, so the bra you buy at 20 weeks is the one you feed in and the one you're still wearing months later. That's the whole reason to buy a maternity bra rather than a bigger ordinary one.
Do maternity knickers help with leaks?
They help you get through the day. The gusset is anti leak and quick drying, and triple layered on the over the bump pair, so a sneeze or the extra discharge doesn't mean a change of clothes. The fix for the leaks themselves is the NHS's pelvic floor routine, 3 sets of 8 squeezes a day, which every pregnant woman is meant to do whether she leaks or not.
Next: the maternity underwear collection has both pairs of knickers and all four bras, the size guides are linked above, and the hospital bag checklist is where the packs of five come in.
This is general guidance from the BABYGO® team, not medical advice. Your midwife or GP knows your pregnancy; ask them if anything here doesn't fit your situation.
