Fetal behavior is defined as any fetal
action seen by the mother or fetus diagnosed by
objective methods such as cardiotocography (CTG)
or ultrasound. Analysis of the dynamics of the
fetal behavior with morphological studies has
lead to the conclusion that fetal behavior
patterns are directly reflecting development and
maturation of the central nervous system. The
assessment of fetal behavior by 4D ultrasound
could allow distinction between normal and
abnormal fetal behavior patterns which might
make possible the early recognition of fetal
brain impairment.
Assessment of fetal movements throughout the
pregnancy using 4D ultrasound.
The study group included 144 healthy
pregnant women with single pregnancies between
7-38 weeks of gestation. For the first trimester
of pregnancy we assessed eight types of fetal
movements and for the second and third
trimesters 14 types of fetal movements and
facial expressions. The analyzed parameters for
each trimester of pregnancy can be used for
performing antenatal neurodevelopment test, used
the first time by Professor Kurjak.
After 15-20 minutes 4D ultrasound
examination, we found a pattern of fetal
behavior for each trimester of pregnancy.
Dynamic evaluation of fetal behavior reflects
directly the processes of maturation and
development of the central nervous system. This
can make the difference between normal and
abnormal brain development and may be used for
early diagnosis of neurological disorders that
become manifest in perinatal and postnatal
periods.
Introduction
In the past, registration of fetal movements
and fetal heart rate auscultation were the only
methods of the follow-up of fetal well being. In
the last few decades, the development of new
ultrasound techniques has allowed direct
visualization of the fetus in utero (1,2).
4D ultrasound has recently been introduced
in medical practice and complements 2D and 3D
examination by obtaining images in real time. 4D
ultrasound allows visualization of embryonic
movements two weeks earlier than 2D ultrasound
(1). In comparison with 2D ultrasound, 4D
ultrasound offers real benefits for fetus's
assessment prenatal condition. The most benefits
of 4D ultrasound could be real time assessment
of fetal face, grimacing, breathing movements,
swallowing, mouthing, isolated eye-blinking and
reveals the direction of the limbs. In a
relatively short period of time 4D ultrasound
stimulated multicentric studies on fetal and
even embryonic behaviour with more convincing
imaging than conventional 2D ultrasound.
A large spectrum of neurological problems,
such as attention deficit hyperactivity
disorder, schi zo phrenia, epilepsy, autism
could be result at list in part from prenatal
neurodevelopment pro blems (1,2).
The fetuses with abnormal fetal behaviour
should be followed at least till the age of two
years when their categorization to disabling or
non-disabling cerebral palsy can be possible. It
is well known that fetal movement occurs far
earlier than a mother can register it, at the
end of the embryonic period (1). Pattern of the
mo vements, its quantity and quality is
expanding rapidly during pregnancy, from gross
movements of the whole embryo to organized
movements and facial expressions towards the end
of the pregnancy.
Understanding the relationship between fetal
behavior and brain developmental processes in
different periods of gestation makes it possible
to distinguish between normal and abnormal
central nervous system (CNS) development and
early diagnosis of various structural and
functional abnormalities.
Discussion
In the first trimester, fetal movements grow
rapidly in frequency and complexity. If around 7
weeks of pregnancy only gross movements are
visible, at the end of the first trimester fetus
presents complex movements of the head, limbs
and fingers. Initially hand contact with
different parts of the body or the uterine wall
is accidental (2).
In the second half of the pregnancy, the
motor behavior significantly increases in
frequency and variability. After 15 weeks of
pregnancy, 15 types of movements are finalized
(3): general body movements, isolated arm
movements, isolated leg movements, head
retoflexion, anteflexion and rotation, hand to
head, hand to eye, hand to mouth, hand to face,
hand to ear, mouth movements: yawning, sucking,
swallowing, opening/closing the mouth. Mouth mo
vements could be observed, particularly, du ring
the absence of general movements periods and
they reflect normal neurological development of
the fetus (1,2,5).
Additionally, during the second trimester,
facial expressions and eye movements occur. The
first eye movements are sporadic and occur at
about 18 weeks. Around 24-26 weeks, eye
movements are more frequent and systematic
alternating with periods when they are absent.
All types of facial expressions (movements of
the mouth, smiling, frowning) showed a maximum
frequency at the end of the second trimester
(11).
In late pregnancy, fetal movements show a
decline and the periods of rest start to grow.
This decrease is rather a consequence of the
brain maturation processes than the reduced
amount of amniotic fluid (2,3). The results of
multicentric studies from Croatia, Spain,
Turkey, Qatar, Sudan and Japan, showed similar
distribution of fetal movements according to
gestational age.
The study of fetal behaviour was a concern
(even before the appearance of 4D ultrasound)
for teams coordinated by De Vries and Prechtl.
Five years ago, Professor Kurjak implemented
antenatal neurodevelopment test (KANET) in
Zagreb University hospital. The score is
calculated after the assessment quantitatively
and qualitatively of the parameters described
above. Further, the assessment of the fetal
behaviour was applied in other university
centers from Croatia, Spain, Turkey, Qatar and
Japan. In cases of definitely abnormal or
borderline score the test should be repeated
every two weeks till delivery. After that the
babies require postnatal neurological
development follow-up for a two years
period.
Conclusions
Behaviour is closely related to fetal
development and maturation processes of the
central nervous system. Widespread assessment of
the fetal movements can diagnose early many
neurological diseases that have their origins
more in peri- and postnatal periods than during
intrauterine period.
The identification of neurological problems
during fetal life is based on evaluation of
opening of the eyes, variety of facial
expression, primary reflexes (rhythmical burst
in the sucking pattern) and quality of general
movements. The identification of dynamic and
static patterns of the symptoms may be helpful
to date precisely the time when the insult
occurs. The major problem in studying fetal
behavior is that it requires a significant
amount of time and it has not become an
ultrasound exam routine. The bias in examination
can be eli mi nated by use of ultrasound
recordings. Frequent use of the KANET score
would bring a series of benefits and would solve
situations in which obstetriciens are considered
accountable for neurological injury in the
neonatal period.
