On this page
A shopper who was a size 8 in January might need a size 14 cut by July, and her waist measurement alone can shift several inches between two orders placed six weeks apart. Standard size charts assume a static body, but pregnancy is the opposite of static. That mismatch is why maternity apparel carries some of the most anxious, bracket-heavy purchase behavior in fashion ecommerce.
Why Maternity Fit Breaks the Standard Size Chart
Most size charts are built around a single, fixed set of body measurements per label. Maternity bodies do not hold still long enough for that model to work. A customer's bust, waist, hip, and belly measurements can each move on a different timeline across trimesters, and two people at the "same" number of weeks pregnant can carry very differently depending on body type, whether it's a first pregnancy, and whether they're expecting multiples.
Brands try to compensate with belly panels, stretch fabrics, and "bump-friendly" cuts, but the underlying sizing logic is still often borrowed from standard size charts with a few adjustments. That's a reasonable starting point, but it leaves the shopper to guess how much room she'll actually need by the time the order arrives. For background on why static charts struggle even outside maternity, see how to read a size chart correctly.
The Anxiety-Driven Bracketing Problem
Bracketing — ordering multiple sizes with the plan to return what doesn't fit — is already common in fashion ecommerce, and Gen Z shoppers report doing it at especially high rates, according to the National Retail Federation. Maternity shopping amplifies the same instinct for a different reason: it isn't really about indecision, it's about uncertainty over a body that is actively changing.
A shopper eight weeks from her due date isn't unsure what looks good on her. She's unsure what will still fit her in three weeks, or whether the dress that fits now will be too snug at a baby shower. That uncertainty pushes her to order a size up and a size down "just in case," which is a rational response to an unpredictable variable, but it's expensive for the brand on both shipping and processing.
Consider the layered cost this creates:
| Cost driver | Standard apparel | Maternity apparel |
|---|---|---|
| Timing uncertainty | Low — body is stable | High — body changes weekly |
| Typical bracket size | 1-2 sizes | Often 2-3 sizes, plus style variants |
| Return window relevance | Fixed fit expectation | Fit expectation decays over weeks |
Returns already cost fashion brands tens of billions of dollars a year globally, per McKinsey, and the US return rate for online apparel sits close to 19-20%, per the National Retail Federation. Maternity categories tend to sit above general apparel averages precisely because of this bracketing pattern, which makes it a natural place to invest in better fit guidance rather than just absorbing the returns. For a category-agnostic look at what a healthy benchmark even looks like, see what is a good return rate for fashion ecommerce.
What Shoppers Actually Need: Fit Guidance That Accounts for a Timeline
The core design problem is that a maternity shopper isn't asking "what fits me right now" — she's asking "what will fit me when this actually matters." That's a fundamentally different question than the one most size guidance tools are built to answer, and it means the guidance needs a time dimension, not just a body-measurement dimension.
Useful maternity fit guidance typically needs to account for a few things at once:
- Current measurements versus projected measurements, since ordering for "today" often means arriving too small by the delivery date or the event date.
- Garment intent, since a going-home outfit for the hospital has a very different tolerance window than a maternity work blazer bought in month four.
- Stretch and adjustability of the specific garment, since a wrap dress and a structured coat behave completely differently as the body changes.
None of this is solved by a bigger size chart. It requires guidance that treats fit as a moving target and gives the shopper a defensible reason to trust one size over bracketing three.
Where YourSizer Fits
YourSizer's role here is narrow and practical: give the shopper a size recommendation and a virtual try-on preview based on her actual measurements, rather than asking her to map herself onto a chart built for a static body. For maternity specifically, that means the recommendation logic can weigh current measurements alongside garment stretch and cut, so the suggestion reflects how the piece is likely to wear, not just a label.
The try-on visualization also does real work in this category. Seeing an approximation of how a specific silhouette sits on a body shape closer to her own gives a maternity shopper more confidence than a flat product photo on a non-pregnant model, which is still the norm on many maternity product pages. That confidence is what actually reduces the impulse to bracket — she's ordering one size because she has a concrete reason to believe it, not because she's playing it safe against three possible outcomes. This mirrors what we see generally: better pre-purchase fit signal reduces the incentive to hedge with extra sizes, a pattern covered in how to reduce bracketing in fashion ecommerce. The same fit-confidence mechanism that lowers bracketing across fashion broadly is what makes it useful in a category where the body itself is the variable, not just personal preference.
Frequently Asked Questions
Does virtual try-on account for pregnancy weight and shape changes over time?
The visualization reflects the measurements and body shape provided at the time of the session, so it's most accurate as a snapshot rather than a forecast. The practical approach is to pair it with size guidance that factors in garment stretch and intended wear timeline, so the recommendation isn't just "what fits today" but "what has enough room to fit through the period you're buying it for." Brands that sell adjustable or wrap-style maternity pieces get more mileage from this than those selling structured, non-stretch garments.
Is maternity sizing different enough from standard sizing to need its own logic?
Yes, in a meaningful way. Standard sizing assumes one stable set of measurements maps to one label, while maternity garments are designed to accommodate a range of measurements within the same size, often across many weeks of change. A recommendation engine tuned only for standard apparel will tend to under-recommend room in early pregnancy and over-recommend it late, so maternity-aware logic needs its own tolerance bands rather than reusing the general apparel model unmodified.
Will offering better fit guidance actually reduce returns in a category with such high bracketing?
Directionally, yes, based on the general pattern across fashion ecommerce: when shoppers have higher confidence in a single size, the rate of multi-size ordering drops, because the reason to bracket in the first place is uncertainty. Maternity won't fully match the return rates of stable-body categories since some genuine mid-order body change is unavoidable, but reducing the anxiety-driven portion of bracketing — the "just in case" orders placed out of pure uncertainty rather than real need — is where the improvement shows up. That's a meaningfully large share of maternity returns even if it isn't all of them.
Conclusion
Maternity apparel will always carry more return complexity than standard categories, because the body it's sized for is genuinely in motion. The opportunity isn't eliminating that variability — it's giving shoppers enough confidence in a single size that they stop hedging against uncertainty with multiple orders. As fit guidance tools get better at reasoning about garment stretch and intended timeline rather than a single fixed measurement, maternity retailers have a real chance to close the gap between this category's return rates and the rest of apparel.