Surely on more than one occasion you have heard a woman who has had a baby say that since pregnancy shoes tighten more, and perhaps say otherwise, that she has more shoes left over. The reason? That during pregnancy the foot can grow, but it can also diminish.
It sounds strange, it sounds unlikely, but it still happens. It's more, it happens to 6 out of 10 women, to a greater or lesser extent (many hardly notice), and although a few years ago we already explained one of the reasons why they grow, a study published in the magazine American Journal of Physical Medicine & Rehabilitation not only confirms that feet may increase in size in pregnancy, but can also be reduced, and also gives us more data.
The foot can grow up to 1cm
To do the study, a sample of 49 women was taken. Under the hypothesis that pregnancy could change the shape and size of their feet, they compared data collected in the first trimester of pregnancy with others who took 19 weeks after delivery.
The researchers saw that in many women the height of their plantar arches was modified during pregnancy, increasing or decreasing the size of the foot. The modification in the foot seemed to be greater if the pregnancy was the first.
The variations were from 4mm of reduction in the length of the foot to 10mm of increase (1cm), and as you can see in the following graph, the most common is that: that the foot grows between 2 and 4mm, which could mean an average increase to one size in the shoes.
In the following table you will see the reason. The bridge became more pronounced or less during pregnancy, with variations ranging from 3mm height gain to 5mm loss:
And that, why does it happen?
Variations in size are a consequence of weight variation (the foot has to bear a different weight), of the possible modification of the gesture when walking (some pregnant women walk differently and wear different footwear) and hormonal changes which provide more laxity to the joints, to prepare the body for childbirth.
During pregnancy, a hormone called relaxin, which is always segregated, reaches greater peaks, thus increasing its function. As you can imagine by name, the relaxin is responsible for relax the ligaments of the pelvic joints, so that at the time of delivery you have mobility: the relaxin makes the bones that make up the pelvis can move to open, widen the birth canal and facilitate the birth of the baby.
Well, the same relaxin that helps the pelvis to open makes the rest of the ligaments are also more elastic and that is why the foot is more lax. By having more elastic ligaments, the arches of the foot modify their height and that causes the decrease in length, and in most cases, feet grow.
Can it cause a problem?
It depends a lot on what the variation in the shape and size of the foot is, but the researchers suggest that it could happen, and leave the door open for further research. The modification of the height of the arch of the foot can cause certain musculoskeletal disorders in women, by distributing the weight differently and loading the weight differently.
In many cases the foot returns to its original position months after delivery, but in others it does not. In such a case, it might be necessary go barefoot the longer the better, in a progressive manner (the arch is strengthened and becomes more pronounced again), or if the discomfort is considerable, seek professional help at the physiotherapist.
Photos | iStock
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