Quick Answer: Between roughly a quarter and two thirds of women see a lasting increase in foot length or width after pregnancy, most often after a first baby. The cause is a combination of relaxin-driven ligament laxity, extra load, and fluid retention, and the arch often drops without fully returning. That change alters how your knees and hips load during walking and training, so refitting shoes and rebuilding foot and hip strength matters more than most postpartum plans acknowledge.

Nobody warns you about this one. The bump gets a hundred articles and the fact that your trainers no longer fit gets a shrug and a joke about buying new shoes.

What actually changes in the foot during and after pregnancy?

Three separate processes act on the foot at the same time, which is why the change can be lasting rather than temporary.

Ligament laxity. Relaxin and other hormonal changes increase the extensibility of ligaments throughout pregnancy, not only in the pelvis. The foot is held together by a dense network of ligaments, and the medial longitudinal arch - the one on the inside of your foot - depends on them heavily. When those ligaments become more extensible, the arch has less passive support.

Increased load. Typical pregnancy weight gain guidance ranges from around 11 to 16kg for a person starting in the healthy BMI range, and more for some. All of it passes through two feet whose ligaments are simultaneously more compliant. The arch flattens under that load, which lengthens the foot - the same way a spring extends when compressed from above.

Fluid retention. In the third trimester most women retain significant fluid, and the feet and ankles are where it collects. This part genuinely does resolve, usually over two to six weeks postpartum, and it is why the early postpartum foot can look dramatically different from the six-month foot.

The first two processes are the ones that produce lasting change. Research measuring arch height and foot length before and after pregnancy has consistently found reductions in arch height and increases in foot length in a substantial proportion of women, with first pregnancies showing the largest effect. Subsequent pregnancies tend to add less, which suggests much of the structural change happens once.

What that means practically: the foot you have at six months postpartum is likely closer to your new baseline than the foot you had before. Waiting for it to go back is often waiting for something that will not happen - and that is not a failure of recovery, it is a structural change to accommodate rather than reverse.

How much change is normal, and when does it settle?

Studies looking at foot dimensions across pregnancy have found lasting increases in foot length in roughly a quarter to two thirds of women, with typical increases of around 2 to 10mm. That is often the difference between a half size and a full size, and width frequently changes more noticeably than length.

The timeline matters as much as the amount. Roughly:

• Weeks 0 to 6: fluid retention still resolving. Feet may be visibly swollen, particularly after a caesarean or with a longer labour. Do not buy shoes now.
• Weeks 6 to 12: most fluid gone. What remains is closer to structural, though ligament laxity is still elevated, especially while breastfeeding.
• Months 3 to 6: ligament properties are largely settling. This is the sensible window for a proper refit.
• Months 6 to 12: if the arch is going to recover some height, this is where you would see it. Many arches settle lower and stay there.

Signs the change is structural rather than transient: your usual shoes feel tight across the width rather than the length, an old pair shows a new wear pattern on the inner edge, or you can see more of the inner arch flattening towards the floor when you stand compared with photos or memory from before.

Signs to get checked rather than accommodate: persistent pain in the heel or arch that is worst on the first steps of the morning, numbness or tingling in the foot, one foot changing markedly more than the other, or swelling in one leg only. That last one in particular warrants prompt medical attention rather than a new pair of trainers. This is general information, not medical advice.

Why does a dropped arch show up as knee and hip pain?

Because the foot is the first joint in a chain, and a change at the bottom propagates upwards.

When the arch lowers, the foot pronates more - it rolls slightly inward through the stance phase of walking. Pronation is normal and necessary; the issue is amount and timing. Excess pronation drives the shin bone into internal rotation, which changes how the kneecap tracks in its groove and increases the demand on the muscles controlling hip rotation.

So a postpartum foot change can present as:

• Pain around or behind the kneecap, especially on stairs or downhill walking
• Outer hip or gluteal fatigue and aching, because the hip stabilisers are working harder to control rotation
• Arch or heel pain, particularly the first-steps-of-the-morning pattern that suggests plantar fascia irritation
• A feeling of clumsiness or instability on uneven ground, since a flatter foot has less spring and less proprioceptive feedback

This matters because postpartum knee and hip complaints get attributed almost automatically to core weakness, pelvic floor issues, or carrying a baby on one hip. All of those are real and common. But if the pain started when you returned to walking or running, and your shoes stopped fitting at the same time, the foot deserves to be in the differential.

There is also a load story. Carrying a baby, a car seat, and a changing bag adds meaningful weight - a car seat with a baby in it can easily reach 8 to 10kg - and it is usually carried asymmetrically. A more compliant foot under an asymmetric load is a reasonable recipe for one-sided symptoms, which is exactly the pattern many people report.

What should you actually do about shoes?

This is the highest-value, lowest-effort intervention available, and most people delay it out of a sense that buying bigger shoes is admitting defeat.

Get measured properly, at around three to six months postpartum, in the late afternoon. Feet swell across the day, more so while you are still recovering, and a morning fitting produces a shoe that is tight by evening. Measure both feet - postpartum asymmetry is common - and fit to the larger one.

Prioritise width over length. The most frequent postpartum complaint is not that shoes are too short but that they are too narrow. Many brands offer wide fittings, and a correctly wide shoe in your old length often solves the problem entirely. Squeezing a wider foot into a standard width is a reliable route to neuroma-type symptoms and toe pain.

What to look for in a training shoe now:

• A firm heel counter - squeeze the back of the shoe; it should resist rather than collapse
• Torsional stability - twist the shoe; it should resist twisting through the midfoot
• Enough toe box depth and width to leave about a thumb-width in front of the longest toe
• A removable insole, so you can add support or an orthotic later without changing shoes

Replace the barefoot-style shoes for now if you were wearing them. Minimal shoes place all the arch-support demand on tissues that are currently more compliant. That is not an argument against minimal footwear in general; it is an argument for not asking a lax foot to do the hardest version of the job while you rebuild strength.

Do not skip house shoes. Most postpartum days are spent almost entirely at home, barefoot on hard floors, carrying a baby. A supportive indoor shoe or a firm slipper covers far more of your actual weekly load than your training shoes do.

How do you rebuild foot and lower-leg strength safely?

Passive support handles the load; strength changes what your foot can do on its own. You want both, and the strength part is usually neglected.

Start with intrinsic foot work, from about six weeks or whenever you have clearance to begin gentle exercise.

Short foot exercise. Sitting, foot flat, draw the ball of the foot towards the heel to raise the arch without curling the toes. Hold 5 seconds, 10 reps, twice a day. This targets the small intrinsic muscles that support the arch actively. It feels like nothing is happening for the first week; that is normal.

Toe yoga. Lift the big toe while keeping the others down, then reverse. 10 each way. Poor big-toe control is common and it matters for push-off.

Then progress to loaded work, around 8 to 12 weeks and building slowly.

Heel raises. Both legs first, 15 reps, 3 sets, with the heel travelling straight up over the second toe rather than drifting outward. Progress to single leg when both-leg raises are easy and painless - typically several weeks later.

Single-leg balance progressions. 30 seconds on a firm surface, then eyes closed, then on a cushion. This rebuilds the proprioceptive input a flatter foot delivers less of.

Then add the hip, because the chain runs upward.

Side-lying hip abduction, 12 to 15 reps, 2 to 3 sets each side, and step-downs from a low step, 8 to 10 reps watching that the knee does not fall inward. Hip strength is what controls the rotation that a pronating foot invites, and it is the piece that most often prevents the knee pain.

Build volume before intensity. Walking is the ideal postpartum foot rehabilitation - progressive, low impact, and functional. Add 10 percent per week to your walking volume rather than jumping. Return to running deserves its own timeline and ideally a pelvic health physiotherapy assessment, and most guidance suggests waiting until at least 12 weeks with a graded programme.

What Nobody Tells You About Postpartum Feet

The change is often permanent, and that is not a recovery failure. People wait a year for their old shoe size to return, wearing shoes that do not fit in the meantime. The arch that dropped under a pregnancy’s worth of load and ligament laxity frequently stays lower. Accommodating it early costs you nothing; waiting costs you a year of poor footwear.

First babies change feet the most. If your feet changed after your first and not after your second, that is the documented pattern rather than something unusual. Most of the structural change happens once.

Breastfeeding may extend the laxity window. Hormonal changes associated with lactation can keep ligaments more compliant for longer. It is a reason to be patient with a refit and unhurried about minimal footwear, not a reason to avoid exercise.

Nobody checks your feet. Postpartum checks focus, quite reasonably, on the pelvic floor, the abdominal wall, mood, and bleeding. Feet are outside the standard script, so if they changed you will have to raise it yourself. Say it explicitly: my shoe size changed and my knees hurt when I walk.

The car seat is heavier than your training weights. Many women return to structured exercise cautiously while lifting a 9kg car seat one-handed, twenty times a day, at arm’s length. The everyday load is the real load. Getting shoes and hip strength right serves that far more than it serves your gym sessions.

One-sided change deserves attention. Feet change asymmetrically fairly often, but a marked difference on one side, or swelling in one leg alone, should be looked at rather than absorbed into the general postpartum background. Sudden one-sided leg swelling, pain, redness, or warmth needs urgent medical assessment.

FAQ: Postpartum Foot Questions, Answered

Will my feet ever go back to their old size?

Sometimes partly, often not. Fluid-related swelling resolves in the first six weeks or so; structural change from arch flattening frequently persists. Refit at three to six months rather than waiting a year to find out.

Do I need orthotics?

Many people do well with a supportive shoe and consistent foot and hip strength work. If you have persistent arch or heel pain, a marked change on one side, or pain that limits walking, an assessment with a podiatrist or physiotherapist is worthwhile - off-the-shelf inserts help plenty of people, and a professional can tell you whether custom is justified.

Is it safe to run if my arch has dropped?

Generally yes, with an appropriate shoe, a graded return, and ideally a pelvic health assessment first. Most guidance suggests waiting until at least 12 weeks postpartum and building gradually. Pain that worsens run to run is a signal to reassess rather than push.

Should I avoid barefoot time entirely?

No - barefoot work on soft surfaces is part of rebuilding intrinsic foot strength. What is worth avoiding for now is spending all day barefoot on hard floors while carrying extra load, which is the highest-demand version with none of the training benefit.

Why do my feet hurt most first thing in the morning?

First-step heel or arch pain that eases after a few minutes is a classic plantar fascia pattern. It is common postpartum and usually responds to supportive footwear, calf and foot strength work, and load management. If it persists beyond a few weeks, get it assessed.

TL;DR:

• A quarter to two thirds of women see lasting foot length or width change, usually 2 to 10mm, mostly after a first baby
• Fluid resolves in about six weeks; arch flattening from ligament laxity and load often does not
• A lower arch increases pronation, which can present as kneecap pain, outer hip ache, or arch pain
• Refit shoes at three to six months, in the afternoon, prioritising width and fitting the larger foot
• Rebuild with short foot exercise and toe control first, then heel raises and single-leg balance, then hip strength
• Raise it at your postpartum check yourself - feet are not on the standard script

The part that catches people out is not the change itself but the assumption that it is temporary. Treat the six-month foot as your new baseline, dress it in something that fits properly, and spend ten minutes twice a week rebuilding what the ligaments used to do passively. That combination resolves a surprising share of postpartum knee and hip complaints that get blamed on everything else.

See It in Motion

Seen here: Maternity Capris with Side Pockets — shop it on bubblelime.com