Facial expressions such as
laughter and crying develop before birth and become more complex as the
pregnancy progresses to 36 weeks of gestation, according to a study led by
British researcher Nadja Reissland.
development of facial movements in a fetus is essential for various functions
after birth - the infant sucking movement required for feeding, jaw and tongue
movements necessary for speech, and movements in the face necessary for facial
expressions. It is also necessary for the postnatal bonding between the baby
and parents and theoretically for the study of the origins of affect.
facial muscles begin to develop by 8 weeks and all the muscles used in facial
expressions are formed by 16 weeks, it is possible to evaluate fetal facial
expressions only between 24-36 weeks as the adipose tissue builds up during
Facial Action Coding System (FACS) was available for infants and for adults but
no comprehensive coding system applied to fetuses. So, the aim of this study
was to develop a coding system for fetal facial movement to address two
questions - 1) Does the complexity of facial movement increase with fetal age?
And 2) Do facial movements associated with positive and negative emotions
emerge from the second to third trimester of pregnancy?.
researchers studied the fetal facial expressions by applying the Facial Action
Coding System (FACS) on modern 4-D ultrasound recordings. With increasing
gestational age fetal movements of the face, limbs and torso become correlated
with the structural development of the central nervous system (CNS). This
development demonstrates that the connection between cerebral cortex and
peripheral structures of the fetus are functional. In compromised fetuses this
development is at variance from normal fetuses. Therefore by evaluating fetal
expressions it is possible to predict the healthy brain function of the fetus.
Based on research using facial muscle
movements to code recognizable facial expressions in adults and adapted for
infants, the scientists have defined two distinct fetal facial movements-
'cry-face-gestalt' and 'laughter-gestalt'. Both the movements are made up of up
to 7 distinct facial movements. During the study when two healthy female
fetuses were scanned at different gestational ages in the second and third
trimester it was observed that the number and complexity of simultaneous
movements increased with gestational age. It was noted that between 24-35 weeks
the mean number of co-occurrences of 3 or more facial movements increased from
7-69 percent. The number of co-occurrences of 3 or more movements making up a
'cry-face gestalt' facial movement increased from 0-42 percent while that of
'laughter-face gestalt' increased from 0-35 percent. Recognizable facial
expressions were also observed to develop during this period.
Nadja Reissland from Durham University, the lead researcher of this study says,
'This research provides the first evidence of developmental progression from
individual unrelated facial movements toward fetal facial gestalts. We propose
that there is considerable potential of this method for assessing fetal
development: Subsequent discrimination of normal and abnormal fetal facial
development might identify health problems in utero'. This means, this coding
and analysis allows researchers to 'objectively trace the increasing complexity
of movements over time which results in recognisable facial expressions'.
this fetal facial movements coding method:
serve as a marker for normal development;
considerable potential for assessing the integrity of the fetal central nervous
possibly be used for the detection of functional or structural brain disorders;
subsequently discriminate between normal and abnormal fetal facial development
to identify health problems in utero.
Expressions Develop before Birth?; Nadja Reissland et al; Plos One 2011.