<s>
Fetal	B-Algorithm
electroencephalography	I-Algorithm
,	O
also	O
known	O
as	O
prenatal	B-Algorithm
EEG	I-Algorithm
includes	O
any	O
recording	O
of	O
electrical	O
fluctuations	O
arising	O
from	O
the	O
brain	O
of	O
a	O
fetus	O
.	O
</s>
<s>
Doctors	O
and	O
scientists	O
use	O
EEGs	B-Application
to	O
detect	O
and	O
characterize	O
brain	B-Application
activity	I-Application
,	O
such	O
as	O
sleep	O
states	O
,	O
potential	O
seizures	O
,	O
or	O
levels	O
of	O
a	O
coma	O
.	O
</s>
<s>
EEG	B-Application
captures	O
the	O
electrical	O
activity	O
in	O
the	O
vicinity	O
of	O
the	O
recording	O
electrodes	O
.	O
</s>
<s>
Given	O
the	O
difficulty	O
of	O
attaching	O
electrodes	O
to	O
a	O
fetus	O
inside	O
a	O
uterus	O
,	O
doctors	O
and	O
scientists	O
use	O
a	O
variety	O
of	O
techniques	O
to	O
record	O
fetal	O
brain	B-Application
activity	I-Application
.	O
</s>
<s>
The	O
three	O
most	O
common	O
techniques	O
for	O
recording	O
electrical	O
brain	B-Application
activity	I-Application
before	O
birth	O
include	O
:	O
</s>
<s>
The	O
recording	O
of	O
the	O
youngest	O
fetus	O
was	O
performed	O
between	O
43	O
and	O
45	O
days	O
gestation	O
and	O
revealed	O
some	O
EEG	B-Application
features	O
observed	O
in	O
newborns	O
.	O
</s>
<s>
To	O
follow	O
up	O
,	O
in	O
1955	O
,	O
Bernstine	O
,	O
Borkowski	O
and	O
Price	O
examined	O
and	O
described	O
32	O
fetal	B-Algorithm
EEGs	I-Algorithm
recorded	O
from	O
the	O
maternal	O
abdomen	O
and	O
cervix	O
during	O
labor	O
.	O
</s>
<s>
From	O
1955	O
to	O
1976	O
,	O
many	O
scientific	O
groups	O
made	O
EEG	B-Application
recordings	O
from	O
electrodes	O
placed	O
on	O
the	O
maternal	O
abdomen	O
,	O
or	O
placed	O
on	O
the	O
cervix	O
using	O
a	O
speculum	O
,	O
and	O
techniques	O
continued	O
improving	O
.	O
</s>
<s>
In	O
the	O
1980s	O
,	O
functional	B-Algorithm
MRI	I-Algorithm
or	O
magnetoencephalography	B-Algorithm
became	O
the	O
primary	O
research	O
tools	O
for	O
the	O
prenatal	O
study	O
of	O
human	O
brain	O
development	O
;	O
however	O
,	O
fetal	B-Algorithm
EEG	I-Algorithm
prevailed	O
in	O
clinical	O
settings	O
for	O
determining	O
sleep	O
states	O
in	O
the	O
unborn	O
,	O
or	O
fetal	O
distress	O
.	O
</s>
<s>
The	O
team	O
used	O
needle	O
electrodes	O
to	O
record	O
brain	B-Application
activity	I-Application
at	O
3	O
millimeters	O
and	O
1	O
centimeter	O
below	O
the	O
brain	O
surface	O
.	O
</s>
<s>
The	O
doctors	O
also	O
observed	O
patterns	O
that	O
resembled	O
"	O
sleep	B-Algorithm
spindles	I-Algorithm
"	O
in	O
adults	O
.	O
</s>
<s>
The	O
original	O
fetal	B-Algorithm
EEGs	I-Algorithm
came	O
from	O
recordings	O
through	O
the	O
maternal	O
abdomen	O
.	O
</s>
<s>
However	O
,	O
electrical	O
activity	O
from	O
the	O
mother	O
's	O
heart	O
,	O
abdominal	O
and	O
uterine	O
muscles	O
all	O
create	O
artifacts	O
in	O
the	O
fetal	B-Algorithm
EEG	I-Algorithm
recording	O
.	O
</s>
<s>
An	O
artifact	O
is	O
electrical	O
activity	O
detected	O
by	O
the	O
EEG	B-Application
that	O
comes	O
a	O
source	O
that	O
the	O
scientist	O
does	O
not	O
want	O
to	O
measure	O
.	O
</s>
<s>
Even	O
with	O
modern	O
techniques	O
,	O
scientists	O
still	O
have	O
difficulties	O
detecting	O
brain	B-Application
activity	I-Application
recorded	O
from	O
outside	O
the	O
womb	O
.	O
</s>
<s>
Doctors	O
can	O
safely	O
record	O
EEG	B-Application
from	O
the	O
fetus	O
without	O
interference	O
from	O
the	O
maternal	O
heartbeat	O
and	O
uterine	O
muscles	O
by	O
attaching	O
suction-cup	O
electrodes	O
to	O
the	O
scalp	O
of	O
the	O
unborn	O
during	O
labor	O
and	O
delivery	O
.	O
</s>
<s>
Both	O
before	O
and	O
during	O
labor	O
,	O
trace	O
alternant	O
patterns	O
can	O
be	O
observed	O
in	O
the	O
fetal	B-Algorithm
EEG	I-Algorithm
.	O
</s>
<s>
During	O
active	O
REM	O
sleep	O
,	O
EEG	B-Application
recordings	O
from	O
the	O
fetus	O
mostly	O
show	O
low	O
voltage	O
fast	O
activity	O
.	O
</s>
<s>
During	O
quiet	O
non-REM	O
sleep	O
,	O
EEG	B-Application
recordings	O
from	O
the	O
fetus	O
mostly	O
show	O
high	O
voltage	O
slow	O
activity	O
.	O
</s>
