Fetuses are able to predict, rather than simply react to, their own hand movements towards their mouths in the later stages of gestation, according to novel research by psychologists at Durham and Lancaster universities.
“Increased touching of the lower part of the face and mouth in fetuses 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 of the Department of Psychology at Durham University.
“What we have observed are sequential events, which show maturation in the development of fetuses, 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.”
The study, published in the journal Developmental Psychobiology, involved eight girls and seven boys. No difference in behavior was noted between boys and girls.
For the study, the researchers carried out a total of 60 scans of 15 healthy fetuses at monthly intervals between 24 weeks and 36 weeks gestation.
Fetuses in the earlier stages of gestation more frequently touched the upper part and sides of their heads. But as they developed, they began to increasingly touch the lower, more sensitive, part of their faces, including their mouths.
By 36 weeks, researchers witnessed a much greater proportion of fetuses opening their mouths before touching them. This suggests that they were able to anticipate their hands about to touch their mouths, rather than reacting to the touch of their hands.
Greater sensitivity around a fetus’ mouth at this later stage of pregnancy could suggest 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 fetuses.
The researchers noted that this phenomenon could be an indicator of healthy development, as fetuses who are delayed in this development due to illness, such as growth restriction, might not exhibit the same behavior observed during the study.
“This effect is likely to be evolutionally determined, preparing the child for life outside the womb. Building on these findings, future research could lead to more understanding about how the child is prepared prenatally for life, including their ability to engage with their social environment, regulate stimulation and being ready to take a breast or bottle,” said Brian Francis, Professor of Social Statistics at Lancaster.
The study adds to previous research by Durham and Lancaster on fetal development. Earlier this year, another study revealed that unborn babies practice facial expressions in the womb in what is thought to be preparation for communicating after birth.
The researchers said that the latest findings could enhance knowledge about premature babies, their readiness to interact socially, and how they calm themselves by sucking on their thumb or fingers.
Source: Durham University