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SECOND TRIMESTER
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14 WEEKS AFTER CONCEPTION
(16 WEEKS AFTER THE LAST MENSTRUAL PERIOD)
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The fetus is about 4 ¾ inches from
crown to rump and weighs about 3 ½ ounces.
Click
here for picture
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The head is more erect and the arms and legs
are developed.
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Limb movements become more coordinated because
joints will now function.
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16 WEEKS AFTER CONCEPTION
(18 WEEKS AFTER THE LAST MENSTRUAL PERIOD)
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The fetus is about 5 ½ inches long
from crown to rump and weighs between 6 and 7 ounces.
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The skin is transparent. Blood vessels are
very easily seen through the skin.
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Hair and nails begin to grow.
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The fetus can now blink, grasp, and move the
mouth.
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18 WEEKS AFTER CONCEPTION
(20 WEEKS AFTER THE LAST MENSTRUAL PERIOD)
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The fetus is about 6 ½ inches long
from crown to rump and weighs about 10 ounces.
Click
here for picture
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All organs and structures have been formed
and a period of simple growth begins.
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The skin is covered by vernix, a waxy substance
that protects the skin.
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Most women feel the fetus moving or kicking.
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The sex of the fetus can now often be more
readily identified by ultrasound.
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Some experts have concluded the fetus is capable
of feeling physical pain at about this time of development;
other experts have concluded the fetus feels pain during
later stages of development. This issue can be explored
in the reference section of this website.
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20 WEEKS AFTER CONCEPTION
(22 WEEKS AFTER THE LAST MENSTRUAL PERIOD)
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The fetus is about 7 ½ inches long
from crown to rump and weighs from 14 to 16 ounces (1 pound).
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The fetus is more active, kicking, sucking,
and turning in the uterus.
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A period of extremely rapid brain development
is beginning.
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The eyelids, eyebrows, and fingernails are
well developed.
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Survival rates for fetuses born at 22 weeks'
gestation are low.
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22 WEEKS AFTER CONCEPTION
(24 WEEKS AFTER THE LAST MENSTRUAL PERIOD)
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The fetus is about 8 ½ inches long
from crown to rump and weighs about 1 ¼ pounds.
Click
here for picture
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The bones of the ears harden, enabling sound
conduction. The fetus can now hear voices or sounds of its
mother's breathing or heartbeat.
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The proportions of the face and body begin
to assume the appearance of an infant near its due date.
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A period of substantial weight gain is beginning;
fat layers are starting to form.
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Lungs are still immature; a fetus born at
this time will attempt to breathe, but is not likely to
survive without very intensive care. In Alaska, with optimal
care, the survival rate of fetuses born at 23 weeks gestation
is approximately 63%. If born at 24 weeks gestation, survival
odds improve to 70%.
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24 WEEKS AFTER
CONCEPTION
(26 WEEKS AFTER THE LAST MENSTRUAL PERIOD) |
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The fetus is about 9 inches long from crown
to rump and weighs 1½ to 1 ¾ pound.
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The body is lean and the skin appears wrinkled
due to the lack of body fat.
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In Alaska, with optimal care, survival is
80% likely for fetuses born at this gestational age.
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