Pregnancy changes your body quickly. Postpartum changes it again. And if you’re breastfeeding, fluctuations can happen daily.

The right maternity bra size isn’t about squeezing into a number — it’s about allowing room for change while maintaining proper support.

Here’s how to measure correctly — and how to choose your OVUM size with confidence.

Step 1: Measure Your Band Size (Underbust)

Did you know that the band provides the majority of your bra’s support? Not the straps! So, if the band fits correctly, everything else falls into place.

To measure:

• Wrap a soft measuring tape snugly around your ribcage, directly under your bust.

• Keep the tape level and firm, but not tight.

• Round to the nearest whole number.

For a visual step-by-step guide, visit our Find Your Fit page, where we show you exactly how to measure for your OVUM size.

A Note on Band Comfort and a Gift from OVUM

Unlike traditional bras, every OVUM bra includes a matching bra extender.

This means:

• Your bra can expand as your ribcage widens during pregnancy.

• You don’t necessarily need to size up for band growth.

• You gain longevity without compromising structure.

It’s built-in flexibility — without losing support.

Step 2: Measure Your Cup Size (Overbust)

Measure around the fullest part of your bust, keeping the tape level and relaxed.

This measurement gives us your cup size and, when paired with your underbust, determines your perfect fit.

If you’re between cup sizes, consider your stage:

• Early pregnancy: choose your closest size.

• Later pregnancy or breastfeeding: allow for fullness.

OVUM bras feature expandable cups that adapt up to two cup sizes. This means your bra adjusts as your breasts grow — reducing the need to replace sizes as you transition.

What a Proper Fit Should Feel Like

A maternity bra should feel secure, not restrictive.

Here’s how to tell if it fits correctly:

The band sits straight across your back.
If it rides up, the band is too loose. This shifts weight to your straps, which increases back strain.

Straps rest comfortably on your shoulders.
They should not dig in. If they do, your band isn’t doing enough of the work.

No spillage at the top or sides.
Overflow means your cup is too small.

No gaping or wrinkling.
Empty space usually means the cup is too large.

You feel supported — even at the end of the day.
You're not rushing to take it off. The best bra is the one you actually forget you're wearing.

Why Fit Matters During Pregnancy and Breastfeeding

During pregnancy, your breasts become heavier and more sensitive. Ligaments stretch. Posture shifts.

During breastfeeding, fullness can fluctuate daily as milk supply adjusts.

Without proper support, you may experience:

• Back and shoulder tension

• Increased breast tenderness

• Skin irritation

• Poor posture and strain

Support isn’t aesthetic. It’s structural — and necessary.

A well-fitted maternity bra reduces pressure on delicate breast tissue while supporting your body through rapid change.

If You’re Unsure Between Sizes

Because every OVUM bra includes:

• Expandable cups (up to two cup sizes)

• A matching and complementary bra extender

You don’t need to aggressively size up “just in case.”

Instead, choose your most accurate size using our Find Your Fit guide. The built-in flexibility is already there to support growth.

This helps ensure better fit, longer wear, and fewer unnecessary exchanges.

Still Unsure? We get it.

Choosing your size online can feel uncertain — especially when your body is changing.

That’s why OVUM bras are intentionally designed with flexibility built in: expandable cups, soft stretch fabric, a matching extender, and a considered structure that adapts with you. Most women find that these thoughtful details significantly reduce the need to exchange sizes.

However, if your fit isn’t quite right, our returns and exchanges process is simple and supportive. Because confidence should extend beyond the fitting room

For full details on sizing, support, and exchanges, visit our FAQ page.

Confidence in Your Choice

Your body is evolving — but your support system shouldn’t feel uncertain.

Measure calmly. Choose accurately. Allow for growth.

OVUM is designed to move with you — through pregnancy, postpartum, and breastfeeding — with structure, softness, and considered design.

You've Got This!

At OVUM, our maternity bras are designed to support your body through pregnancy and breastfeeding. With a wire-free lift, sculpted support, and flexible fabric that adapts to your changing shape, they offer comfort without compromising on elegance.

Explore the collection