Transcript File

Pregnancy
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Pro-life groups and conservative
Christians define conception as the
beginning of pregnancy. The Medical
definition of the start of pregnancy is
about 10 days later at implantation.
Conception to implantation
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The zygote divides into two cells, and then
they subdivide once every 12 to 20 hours
as the zygote travels down the fallopian
tube
5 or so days after conception the group of
cells is called a blastocyst, the inner group
of cells becomes the fetus and the outer
cells will form the placenta
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The outer layer of cells attach to the
uterine wall by secreting enzymes
By day 9 to 12 attachment is completed
and primitive placental blood circulation
begins
By 14 days the very small blob of
undifferentiated tissue is referred to as an
embryo
3 weeks
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The heart begins to beat at about 18 to 21
days after conception
The embryo is 2mm long and most closely
resembles a worm
4 weeks
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The embryo resembles a tadpole and is
about 6mm long
The embryo has structures like the gills of
a fish in the area that will later develop
into a throat
Formation of the placenta occurs
5 weeks
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Tiny arm and leg buds form
Fingerprints are detectable
The face has a distinct reptilian aspect
The embryo still has a tail and can’t be
distinguished from a pig, rabbit, elephant
or chick embryo
6 weeks
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The embryo is 1.5cm long
The face has two eyes on each side of its
head
2 months
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The embryos face resembles that of a
primate but is not fully human in
appearance
10 weeks
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The embryo is now called a fetus
Its face looks human
Its gender may be detectable via
ultrasound
3 months
or the end of the first trimester
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The fetus is now 5 cm long (in 6 wks it’s
trebled it’s size)
Fingernails and bones can be seen
The first trimester is the main period of
organogenesis
The embryo is most sensitive during the
first trimester to threats such as radiation
and drugs which can cause birth defects
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The embryo during the first trimester also
secretes it’s own hormones (hCG) which
acts like LH to maintain the corpus luteum
4 months
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The fetus is 20cm long
The fetus movements may begin to be felt
Its heartbeat can usually be detected
5 months
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The fetus is 30cm long
The fetus has hair on its head
Movements can be felt
At 22 weeks of gestation the fetus’ lungs
may be developed to the point where it
would have a 14.8% chance of survival
6 months
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The fetus is 35cm long
The lungs bronchioles develop
Interlinking of the brain’s neurons begins
Rudimentary brain waves can be detected
7 months
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The fetus is 40cm long
Regular brain waves are detectable which
are similar to those in adults
9 months
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The fetus is 50cm long
A full term fetus is typically born at this
time