Psychologists using 4-d scans found, for the first time, that foetuses were able to predict, rather than react to, their own hand movements toward their mouths as they entered later stages of gestation compared to earlier in a pregnancy. (Agencies)
Researchers from Durham and Lancaster universities carried out a total of 60 scans of 15 healthy foetuses at monthly intervals between 24 weeks and 36 weeks gestation.
Foetuses in the earlier stage of gestation more frequently touched the upper part and sides of their heads. As the foetuses matured they began to touch the lower, more sensitive, part of their faces including their mouths.
By 36 weeks a significantly higher proportion of fetuses were observed opening their mouths before touching them, suggesting that later in pregnancy they were able to anticipate that their hands were about to touch their mouths, rather than reacting to the touch of their hands, the researchers said.
Increased sensitivity around a foetus' mouth at this later stage of pregnancy could mean that they have more awareness of mouth movement, they added.
Previous theories have suggested that movement in sequence could form the basis for the development of intention in foetuses.
The researchers said their findings could potentially be an indicator of healthy development, as arguably foetuses that are delayed in this development due to illness, such as growth restriction, might not show the same behaviour observed during the study.
The research involved eight girls and seven boys and the researchers noticed no difference in behaviour between boys and girls.
"Increased touching of the lower part of the face and mouth in foetuses could be an indicator of brain development necessary for healthy development, including preparedness for social interaction, self-soothing and feeding," said lead author Dr Nadja Reissland, in the Department of Psychology, at Durham University.
"What we have observed are sequential events, which show maturation in the development of foetuses, which is the basis for life after birth.
"The findings could provide more information about when babies are ready to engage with their environment, especially if born prematurely," Reissland said.
The study builds on previous research by Durham and Lancaster into foetal development. Earlier this year another of their studies showed that unborn babies practice facial expressions in the womb in what is thought to be preparation for communicating after birth.
The study was published in the journal Developmental Psychobiology.
Psychologists using 4-d scans found, for the first time, that foetuses were able to predict, rather than react to, their own hand movements toward their mouths as they entered later stages of gestation compared to earlier in a pregnancy.