Maternity Size Guide: How to Choose the Right Size During Pregnancy

Finding the right maternity clothing size shouldn't feel complicated. One of the most common questions expectant mothers ask is:

"Should I buy my regular size in maternity clothes, or size up?"

The good news is that most maternity clothing is designed to fit your pre-pregnancy size. Specialized maternity garments are created with extra room for your growing bump while maintaining the fit through your shoulders, bust, and hips.

Here's everything you need to know about choosing the right maternity size.

Quick Answer: What Size Maternity Clothes Should I Buy?

In most cases, choose your pre-pregnancy size.

For example:

If you wore a Small before pregnancy, start with a Small in maternity clothing.
If you wore a Medium before pregnancy, choose a Medium.
If you wore a Large before pregnancy, select a Large.

Maternity brands design their clothing with pregnancy growth in mind, adding stretch, adjustable features, and room where your body changes most.

Why Maternity Sizing Is Different

Unlike regular clothing, maternity garments are specifically engineered to accommodate your changing shape.

Features often include:

Stretch panels for growing bellies
Adjustable waistbands
Ruched side seams
Nursing-friendly access
Flexible fabrics that adapt throughout pregnancy and postpartum

Because of these design features, sizing up is usually unnecessary.

When Should You Start Wearing Maternity Clothes?

Most women begin wearing maternity clothing between 12 and 20 weeks of pregnancy, though every pregnancy is different.

You may want maternity clothing earlier if:

You're experiencing bloating.
You're carrying multiples.
This is not your first pregnancy.
You prefer comfort over squeezing into existing clothing.

There is no "right" time to switch. The best time is whenever your current wardrobe no longer feels comfortable.

Should You Size Up for Maternity Clothes?

Usually, no.

The only situations where sizing up may be helpful include:

You're between sizes.
You're carrying twins or multiples.
You prefer a looser, oversized fit.
The garment is known to fit small.

For most women, choosing their normal pre-pregnancy size results in the best fit throughout pregnancy.

How Much Weight Do You Gain During Pregnancy?

Healthy pregnancy weight gain varies based on your starting weight and individual circumstances.

Because every pregnancy is unique, maternity clothing is designed with flexibility and stretch rather than requiring you to continually purchase larger sizes.

This is why quality maternity brands focus on adaptable fabrics and thoughtful construction instead of simply making garments larger.

How Should Maternity Jeans Fit?

Maternity jeans should feel comfortable immediately.

They should:

Stay in place without slipping.
Support your bump without pressure.
Allow room for growth.
Feel comfortable when sitting, walking, and bending.

If maternity jeans feel tight around your belly when you first try them on, they're likely too small.

Buying Maternity Clothes That Last Beyond Pregnancy

The smartest maternity wardrobe investments are pieces designed for both pregnancy and postpartum.

Look for:

Nursing-friendly dresses
Maternity and postpartum leggings
Adjustable waist pants
Layering pieces like cardigans and blazers
Quality nursing bras

These versatile pieces provide value throughout pregnancy, postpartum recovery, and beyond.

Frequently Asked Questions

Do maternity clothes run big?

Most maternity clothes are designed to fit true to size based on your pre-pregnancy measurements.

Can I wear maternity clothes postpartum?

Yes. Many women continue wearing maternity clothing for several months after giving birth while their bodies recover.

What if I'm between sizes?

If you're between sizes, consider your preferred fit and the garment's fabric. Stretchy styles often work well in the smaller size, while structured pieces may feel more comfortable in the larger size.

Is maternity sizing the same across brands?

Not always. Always review the brand-specific size chart before purchasing.

The Bottom Line

For most women, the easiest way to shop for maternity clothing is simple:

Start with your pre-pregnancy size.

Quality maternity clothing is designed to grow with your body, support your changing shape, and help you feel comfortable throughout pregnancy and postpartum.

At HauteMama, we carefully curate maternity brands that prioritize fit, comfort, and longevity, helping you build a wardrobe that supports every stage of motherhood without sacrificing your personal style.