Buggy study pushed too far

“Baby buggies which face forwards may stunt children’s development and turn them into anxious adults,” the Daily Mail reported. It said that a study had found that babies suffer more stress and even “trauma” in buggies that face away from their parent.

Despite the news report, there is no evidence from this study that buggies which face forwards cause trauma or have an effect on how the child grows up. Such interpretations of its results are incorrect and could be seen as scaremongering.

The study used heart rate as a measure of infant ‘stress’ and the finding that babies facing forward have slightly higher heart rates is unsurprising as they would be experiencing different stimuli. As such, this may have nothing to do with ‘stress’ levels. The cautious interpretation of the results taken in some parts of the research article must be emphasised. In other areas and in some news reports the results have been over-interpreted and may cause parents unnecessary anxiety.

Where did the story come from?

Dr Suzanne Zeedyk carried out this research in collaboration with the National Literacy Trust. The study was supported by a grant from the Sutton Trust. The study has not been published in a peer-reviewed journal. It is available on the National Literacy Trust website.

What kind of scientific study was this?

There were two parts to this preliminary observational study, both set up to assess if the orientation of a buggy (whether it's facing backwards or forwards) has an effect on the baby sitting in it.

In the first part, the observers systematically documented the social interactions of parents and children that occurred during buggy use. Volunteers observed mothers and babies in 50 public areas across the UK and recorded their behaviour and how they were transported. This included determining how frequently the four main modes of infant transport were used (away-facing buggies, toward-facing buggies, walking and being carried); how the children were behaving (being vocal, being silent, seeking their parent, crying, sleeping); how often parents were speaking to their child; whether the parent talking predicted the child vocalising.

Over a two-month period in 2008, 57 volunteers observed 2,722 parent-infant pairs. As well as recording details of parent and child behaviour, the researchers recorded estimates of the ages of the parent and child.

In the second part of the study, 20 volunteer mothers and their infants (aged between nine and 24 months) were recruited through posters, toddler groups and friendship circles. They were invited to an Infant Study Suite, where they were asked to push the baby in both types of buggy (away-facing and toward-facing). In a similar way to the first part, the amount of social interaction between the pair was assessed (i.e. talking and vocalising). Heart rate monitors were also attached to the babies to record their heart rates during the different buggy trips. All 20 mothers tried each kind of buggy, being randomly assigned to which one they started with.

The researchers say that in this part of the study they were trying to see whether changing the buggy orientation changed the way parents and their children interacted. If it didn’t, then the interactions were more likely to be a feature of the personality of the parent (e.g. talkativeness) and of the infant. The researchers measured parent-child interaction (through observing behaviour and recording talk), infant stress (by measuring the infant’s heart rate) and parent preferences.

What were the results of the study?

In the first part of the study, where parents and children were observed on the street, the research found that the majority of buggies are ‘away-facing’ and that parents talked less to their infants if they were in buggies that faced away from them.

In the second part of the study, where away-facing and toward-facing buggies were tested by mothers and children, mothers spoke more to their children if they were facing them. They also talked more often about different topics and they laughed more with each other. Babies were more likely to fall asleep if they were facing their parents and their heart rate was slightly lower. There was no difference in infant vocalisation between the two different buggy journeys and babies facing their parents cried more often.

What interpretations did the researchers draw from these results?

The researcher concludes that life in a buggy may be more isolating than many parents realise and that the child may be “more emotionally impoverished than is good for children’s development”.

What does the NHS Knowledge Service make of this study?

This small study has highlighted an area that may benefit from further research. This study does not provide reliable evidence that buggy design influences parent-infant interaction or has an effect on infant stress levels. The results do not support extrapolations by both researcher and newspapers that stress levels increase in response to buggy orientation. Parents should not be worried that they are harming their babies by using a forward-facing buggy. The potential benefit from the extra stimulation of looking at the world has not been measured or discussed.

In response to the idea that the babies were stressed by forward-facing journeys, it's important to highlight the problems with this aspect of the study’s measurements. ‘Infant stress’ was assessed by measuring the baby's heart rate (with a sensor attached to its foot) during the journey. As the researcher says, “Measuring the heart rate during a buggy journey is challenging, for monitors are affected by excessive movement (which is of course likely during buggy journey).” This suggests that they may have had problems with their equipment and readings and sensibly report that they only regard these results as “tentative, rather than definitive”.

Secondly, heart rate on its own is not a good measure of stress. Heart rates fluctuate for many reasons, one of which could be excitement or enjoyment. Infants facing forward in their buggies are likely to have seen more things and been more stimulated. Their increased heart rate may be due to this and not stress.

There was no statistically significant difference in heart rates between the groups, so the focus on this as a measure of infant stress is almost a moot point. The researcher has chosen to focus on the heart rate results as a measure of stress, rather than how often the baby cried. In fact, in the second part of the study, more of the babies who faced their parents cried than those who were looking away (though not statistically significant either). Crying is also likely to be an indicator of stress and these results should be given at least as much prominence as those of heart rate differences.

The importance of parent-child interaction for child development and wellbeing cannot be over-emphasised. The National Literacy Trust, a collaborator in this study, is involved in valuable work to encourage early communication between infants and parents. The results from this study are hypothesis generating and may feed into their larger programme of work.

Overall, the results from these two studies taken together are not surprising (i.e. that mothers talked to their babies more and laughed with them more when they were facing them). The benefits of this additional interaction should be interpreted alongside the finding that these babies also slept more. The results have not been adjusted for many factors that may be linked to infant behaviour (e.g. age, duration in the buggy etc). Babies vocalised just as much whether they were facing forward or backwards.

Sir Muir Gray adds...

Don’t worry about the buggy.