Facial expressions such as smiling or crying develop while babies are still in the womb, research has revealed.
Scientists for the first time have been able to show that facial movements of unborn babies become increasingly complex between 24 and 36 weeks gestation.
Facial movements were recorded using 4D ultrasound technology and scientists examined the recordings regularly throughout the period.
Unborn babies at 24 weeks, the first stage of observation, were able to move one muscle in their face at a time.
They could open their mouth, for example, or stretch their lips.
And by 35 weeks unborn babies could combine a number of facial muscle movements, such as stretching their lip, lowering their eyebrows and deepening the nasolabial furrow all at the same time.
One of the researchers, Professor Brian Francis, said: “This is a new and fascinating insight into the remarkable process of fetal development.
“This research has for the first time demonstrated that in healthy fetuses there is a developmental progression from simple to complex facial movements, preparing the fetus for life post birth.”
Dr Nadja Reissland said: “We have found so much more than we expected. We knew that the baby blinks before birth and that some research has identified scowling before birth.
“However in this study for the first time we have developed a method of coding and analysis which allows us to objectively trace the increasing complexity of movements over time which results in recognisable facial expressions.”
The group of researchers from the UK include psychologist Dr Nadja Reissland, Professor James Mason, the Director of Research in Medicine and Health at Durham University, Professor Brian Francis, professor of social statistics at Lancaster University and Dr Karen Lincoln, consultant in Obstetrics and Gynaecology at the James Cook University Hospital, Middlesbrough, where the scans were collected.
Earlier this year unborn twins were filmed interacting with each other just 14 weeks into their mother’s pregnancy by researchers in Italy.
And last October images of a smiling 17-week-old unborn baby were captured in its mother’s womb by the same doctor who pioneered 4D imaging scanning technology.