Measuring newborn foot length: a small step forward?

Our potential to connect newborns to life saving interventions just took another step forward.

We are beginning to have a robust body of evidence to promote simple, affordable and effective interventions for high risk newborns like Kangaroo Mother Care. But identifying the newborns who urgently need that extra care continues to be problematic - even though as many as 80% of them could be recognized by their low birth weight.

Why? Because in sub-Saharan Africa, for example, over half of babies are born at home and are not weighed at birth. Measuring newborn foot length could provide the tool needed to help such women, and their birth assistants, decide whether their baby needs extra care.

With the intention to develop a user-friendly low birth weight screening tool for use in communities where there are no scales, researchers at the Ifakara Health Institute in Tanzania tested how well the length of a baby’s foot can predict whether the baby is low birth weight (<2500g) and in need of extra care. It was found that shorter foot length was highly sensitive, with 87% of low birth weight babies having a foot shorter than 8cm. The specificity of this foot length cut-off was lower at 60%, meaning that 40% of babies with foot length shorter than 8cm were actually not low birth weight. Thus measuring foot length could be used as a screening tool to identify and connect high risk babies born at home to extra care, but there would be some over-diagnosis. These findings were similar to those previously reported from Asia, and new data from Uganda looks likely to reach the same conclusion.

The appropriateness of a highly sensitive but less specific screening tool depends on the type of intervention to be recommended. When the extra care is the effective, cheap and simple Kangaroo Mother Care intervention, arguably some over-diagnosis can be justified: the effect is that more babies benefit from extra feeding and warmth. Currently in Tanzania the usefulness of measuring newborn foot length is being tested further by asking community volunteers and mothers of newborns to try out two different ‘short foot’ measuring tools, and by comparing their findings.

Could something so cheap and so simple be part of the answer?

A community volunteer in southern Tanzania using the foot length indicator printed onto her counselling card to determine whether this newborn baby requires counselling about extra care for small babies.

>> Read the research study