The foot takes its shape in the first trimester, frequently before a pregnancy is confirmed. No ordinary action (diet, exercise, lifting, stress, a medication taken before you knew) is established as a cause.

This belief is close to universal among parents and it has nothing behind it. It is worth saying flatly, because the alternative is carrying it for years.

Cramped positioning genuinely does produce a foot that looks turned in. That is positional talipes, and it straightens on its own or with minimal treatment because nothing structural is wrong.

True clubfoot is different in kind: the bones sit in altered relationships and the soft tissue on the inside and back of the foot is genuinely shorter. Position does not create that, and the distinction is the most consequential one in the first weeks.

See how the two are told apart.

Clubfoot clusters in families and a genetic contribution is well established. What it does not follow is a single-gene inheritance pattern, which is why it appears in one child and not their sibling, and skips generations without anything having changed.

Most affected babies have no family history at all. That is the ordinary case, not the exception.

The genetics has its own page: is clubfoot genetic?

Maternal smoking is the environmental factor most consistently associated with clubfoot, at an adjusted odds ratio of 1.40 in the largest population-based study of it. The numbers behind that association, and the factors that were checked and came back empty, are set out separately. It is one of the few findings in this area that has replicated across studies.

Association is not causation, and the great majority of affected babies are born to people who never smoked. If you did smoke, this is one risk factor among several in a condition that remains mostly unexplained. And nothing you do now is changed by deciding it was your fault.

Ponseti casting corrects the foot in front of the clinician. It does not need to know why the foot formed that way, and the protocol is the same whatever the cause turns out to be.

The one distinction that does change the plan is whether the clubfoot is isolated or occurs alongside another condition, because non-isolated cases typically need more treatment over longer with a higher chance of relapse. That is established by examination, not by finding a cause.

See syndromic clubfoot and what the newborn examination covers.

Clubfoot is one of the better-studied congenital differences. Its epidemiology is well described, the treatment is evidence-based and highly effective, and specific genes have been implicated in some families. What has not been achieved is explaining an individual case, which is true of most multifactorial conditions.

The practical consequence is that the treatment did not wait for the explanation, and your child does not either.