Fetal Development
(according to the Ohio Dept of Health)
The following text is extracted from the booklet Fetal Development &
Family Planning by the Ohio Department of Health. This is not the
entire contents of the booklet, but it is the entire text of the chapter
on fetal development. We have had to omit the photographs, which is too bad
because they are excellent, but they are copyrighted and we do not have
permission to reproduce them.
Note that this material was not written by "anti-abortion
activists"; it was written by medical experts from the Department of
Health.
Fetal Development
Day One
Development begins on the day of fertilization.
A pregnant woman may notice her first missed menstrual
period at the end of the second week after conception, or about
four weeks after the first day of her last
normal period.
There are different kinds of urine tests for pregnancy. Some may not be
accurate for up to three weeks, or five weeks after the first day of your last
normal period.
2 weeks
(4 WEEKS after the first day of the last normal menstrual period)
By the 25th day, the heart begins to beat.
- The human embryo is about one-hundredth (1/100) of an inch long.
- Implantation began the first week and continues.
4 weeks
(6 WEEKS after the first day of the last normal menstrual period)
- The embryo is about one-sixth (1/6) of an inch long.
- By the end of the first month, the embryo has a head and a trunk.
- Structures that will become arms and legs, called limb buds,
begin to appear.
- The heart, now in a tubular
form, begins to beat by the 25th day.
6 weeks
(8 WEEKS after the first day of the last normal menstrual penod)
- The embryo is about half an
inch long and has a four-chambered heart.
- Electrical activity begins in the
developing brain and nervous system.
- The fingers begin to develop.
- The embryo has nostrils.
8 weeks
(10 WEEKS after the first day of
the last normal menstrual period)
The embryo begins to form arms, legs, hands, toes and
a face
- The embryo is about one and one-fifth (1 1/5) inches long.
- The head is about half the size of the embryo.
- The beginnings of all key body
parts are present, although they
are not completely developed or
positioned in their final locations.
- The embryo has ears, fingers, and toes.
10 weeks
(12 WEEKS after the first day of
the last normal menstrual period)
The fetal heart beat can be detected electronically.
- The fetus is about two and one-half (2 1/2) inches from head to
rump.
- The fingernails are developing.
- Between 8 and 10 weeks, the
fetus begins small, random
movements, though they are too
slight to be felt yet.
- The fetal heart beat can be detected electronically.
12 weeks
(14 WEEKS after the first day of the last normal menstrual
period)
The doctor can often tell you if the fetus is a boy or a girl by
special tests.
- The fetus is about three and one-half (3 1/2) inches from head
to rump.
- The fetus is able to swallow, and the kidneys are able to make
urine.
- A doctor may be able to tell you if it's a boy or a girl by
special tests.
- Blood begins to form in the bone marrow.
14 weeks
(16 WEEKS after the first day of
the last normal menstrual period)
- The fetus is about four and three-fourths (4 3/4) inches from
head to rump.
- The head is erect and the legs are developed.
16 weeks
(18 WEEKS after the first day of
the last normal menstrual period)
The fetus can kick, swallow, and sleep.
- The fetus is about five and one-half (5 1/2) inches from head to
rump.
- The ears stick out from the head.
20 weeks
(22 WEEKS after the first day of
the last normal menstrual period)
The fetus has been moving for several weeks. Now the woman begins to
feel these movements.
- The fetus is about seven and one-half (7 1/2) inches from head to
rump.
- The fetus has fingerprints, and may have some head and body
hair.
- Although the fetus has been able to move for several weeks,
movements, known as "quickening," are now felt by the
pregnant woman.
24 weeks
(26 WEEKS after the first day of
the last normal menstrual penod)
About 4 out of 10 babies born now will live
- The fetus is about nine (9) inches from head to rump.
- The fetus can respond to sound.
- About 4 out of 10 babies born now will live.
28 weeks
(30 WEEKS after the first day of the last normal menstrual
period)
At 28 weeks, the fetus has lungs that can breathe air
- The fetus is about ten and one-half (10 1/2) inches from head to
rump.
- The fetus has lungs that are capable of breathing air, although
medical help may be needed.
- The eyes are open.
- About 9 out of 10 babies born now will survive.
32 weeks
(34 WEEKS after the first day of the last normal menstmal
period)
The fetus can grasp firmly
- The fetus is about eleven and three-fourths ( 11 3/4) inches from
head to rump.
- Almost all babies born now will live.
36 weeks
(38 WEEKS after the first day of
last normal menstrual period)
- The fetus is about thirteen and one-half (13 1/2) inches from head
to rump.
- The fetus can grasp firmly.
38 weeks
(40 WEEKS after the first day of the last normal menstrual
period)
The baby has reached full term and is ready to be born
- The fetus is about fourteen (14) inches from head to rump,
and may be 20 inches or more overall.
- The baby is full term and ready to be born.
Posted 9 Sep 2000.
Uncopyrighted work. Public record.
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