Quick answer: the happibump™ maternity co-ord is available in S, M, and L, and because the fabric is a dynamic stretch knit with an over-the-belly panel, most people can size based on their pre-pregnancy size rather than guessing up a size for the bump. If you're between sizes or further along in the third trimester, sizing up is the safer choice for comfort.
How Sizing Works for the happibump™ Co-Ord
Unlike fixed-size maternity wear, the happibump™ co-ord uses a 90% Nylon, 10% Elastane stretch blend with a dedicated over-the-belly panel designed to expand through each trimester. That means the size that fits you in week 10 should continue to fit through week 30 and beyond, rather than needing a size change as your bump grows.
Size Guide by Pre-Pregnancy Size
| Pre-pregnancy size | Recommended happibump™ size |
|---|---|
| UK 6-8 / US 2-4 | S |
| UK 10-12 / US 6-8 | M |
| UK 14-16 / US 10-12 | L |
This is a general starting point — body shape, where you carry your bump, and personal preference for a looser or more fitted feel all factor in.
When to Size Up
- You're in the third trimester and carrying low or wide: a size up gives the belly panel more room to stretch comfortably without feeling restrictive
- You prefer a looser, more relaxed fit: the co-ord is designed to be supportive, but if you typically wear looser clothing, sizing up matches that preference
- You're planning to wear it postpartum: a size that fits comfortably through the third trimester usually continues to work well during early recovery
When to Stay True to Size
- You're in the first or second trimester: the stretch panel hasn't been tested yet by a larger bump, so your regular size should fit well
- You prefer a more fitted, supportive feel: staying true to size gives more compression-like support from the belly panel
What to Check When It Arrives
Once you receive the co-ord, a few quick checks confirm the fit is right:
- The belly panel should sit snugly without digging in or rolling down
- You should be able to sit, bend, and move without the waistband sliding
- The top shouldn't pull tight across the chest or ride up when you raise your arms
If something feels off, happibub backs every order with a 30-day guarantee, so sizing concerns can be addressed after you've actually tried it on.
Frequently Asked Questions
Should I buy maternity clothes in my pre-pregnancy size or size up?
For stretch-panel maternity wear specifically designed to expand through pregnancy, your pre-pregnancy size is usually the right starting point. Fixed-cut, non-stretch maternity clothing is a different story and often does require sizing up.
Will the happibump™ co-ord still fit in the third trimester if I order my regular size?
For most people, yes, thanks to the dynamic stretch panel — but if you tend to carry larger or are unsure, sizing up is the safer choice for the last few weeks specifically.
Can I wear the co-ord postpartum in the same size?
Many people continue wearing the same size through early postpartum recovery, since the stretch and opaque fabric accommodate a changing body in both directions.
What if I'm between two sizes?
When in doubt between two sizes, sizing up generally gives more room for comfort as pregnancy progresses, while sizing down prioritizes a more fitted, supportive feel earlier on.
The Bottom Line
The happibump™ co-ord's stretch construction means sizing is more forgiving than typical maternity wear — start with your pre-pregnancy size, and size up if you're further along or prefer a looser fit. For a deeper comparison with happibub's other maternity piece, see Maternity Leggings vs Maternity Co-Ord, or browse the full Pregnancy collection.