Pregnancy is perhaps the most exciting
phase in the woman’s life. Every woman
has the dream of becoming mother of a
healthy and beautiful baby, after she
gets married. According to the medical
science the pregnancy is divided into
three basic phases called the First
Trimester, Second Trimester and Third
Trimester each of them consisting of
three months. This classification has
been established only to notice the
typical changes in human development
every week of the pregnancy. The weeks
are dated by obstetricians from the
start of the last menstrual cycle period
which means that the ovulation starts
causing by the end of the 2nd week. The
Pics and Videos of week by week
pregnancy will be available soon
Week 1:
This is in fact the 3rd week of
pregnancy when the fertilization of ovum
forming the zygote that undergoes
mitotic cellular division without
increasing in size. The unfilled space
develops marking the blastocyst stage,
containing merely a thin trophoblast
cell rim and the cluster of cells at one
end called embryonic pole that
incorporates the embryonic stem cells.
The blastocyst emerges from its protein
shell called zona pellucida and inserts
into the endometrial lining of mother’s
uterus. The zygote separates into unique
twins in majority case it happens before
day 5.Week
2: The 4th week of pregnancy
when trophoblast cells surrounding the
embryonic cells reproduce and attack
deeper into the uterine lining,
ultimately developing the placenta and
embryonic membranes. Configuration of
the yolk sac/bag takes place. The
embryonic cells compresses into disk of
two cells thickness. If the zygote
happens after day 9, probably it may
cause the risk of the twins being
adjoined.
Week 3:
The 5th week of pregnancy – the first
missed menstrual period, when the
notochord starts developing from the
centre of the embryonic disk. The neural
channel – the future spinal cord starts
producing over the notochord with the
brain protuberance on one of its ends.
The heart tubes also start fusing.
Week 4:
This is the 6th week of pregnancy when
the embryo measures almost 4 millimeters
in length and starts curving to form ‘C’
shape. Then the partitions of future
vertebra start developing. The heart
then protuberances further developing
and initiating beating in the normal
rhythm. Bronchial arches, grooves which
would create structure of the face and
neck. The neural tubes close, the ears
start developing as Otic pits and arm
buds and tail getting visible.
Week 5:
The seventh week of pregnancy
when the embryo measures 8 mm in length,
the lens pits and optic cups start
occurring for developing the eyes, the
primordial mouth and nasal pits start
developing and the brain divides into 5
small bladders including early
telecephalon. Then leg buds and hands
start forming as flat paddles on the
arms. Basic blood starts moving through
primitive vessels connecting to the yolk
bag and chorionic membranes.
Week 6:
The eighth week of pregnancy when the
embryo measures 13mm in length, lungs
start developing, arms and legs extend
with foot and hand noticeable and hands
and feet having figures may yet be
webbed.
Week 7:
The ninth week when embryo
measure 18 mm long, nipple and hair
roots start occurring, toes and elbows
get more visible, impulsive limb
movements may be identified through
ultrasound techniques. All the vital
organs by now start taking place.
Week 8:
The tenth week of pregnancy when embryo
measures 30mm long. By this time the
intestines start rotating, facial
feature developing progresses, the
eyelids and outer portion of ears
develop finally.
Weeks 9, 10,
11 & 12: The eleventh to
fourteenth week of pregnancy, when the
fetus attains 8 cm length, the head
measures almost half of fetus’ size; the
face takes proper human look, eyelids
shuts and doesn’t reopen until 28th
week, tooth buds or baby teeth start
growing and the limbs are longer and
thinner. The fetus makes fist with
fingers; genitals also appear
distinctively and the liver starts
producing red blood cells.
Weeks 13,
14, 15 & 16: The fifteenth to
eighteenth week of pregnancy when fetus
attains 15 cm length. The fine hair grow
on the head, fetal skin gets
transparent, more muscle tissues and
bones develop and bones become stronger,
fetus start making noticeable movements,
it starts sucking with the mouth,
meconium develops in the intestinal
tract and liver pancreas generate fluid
secretions.
Week 18, 19
& 20: The twentieth week when
the fetus touches 20cm mark in length,
fine hair covers the complete body,
eyebrows and eye-lashes develop nails on
fingers and toes takes place, the fetus
gets more active with improved muscle
development. The mother experiences the
fetus’ movements and its heartbeats
could easily be heard through
stethoscope.
Week 21 &
22: The twenty-fourth week,
the fetus shows 28cm length, weighing
around 725 gram, eyes completely
develop, foot and finger prints under
development and air sacs form in the
lungs.
Weeks 23, 24, 25 & 26: The twenty-fifth
to twenty-eighth week, fetus measures 38
cm, weighing around 1.2 kg, brain
develops faster, progressively developed
nervous system, eyes start blinking, and
respiratory system starts
Para-functioning, and if born at
premature stage, survives posing higher
risk of complications or death.
Weeks 27,
28, 29, 30 & 31: The
twenty-ninth to thirty-third week, fetus
scales 38 to 43cm, weighing roughly 2
kg, baby fat level improves, systematic
breathing process starts yet lung are
immature, thalamic brain connections
mediating sensory input, bones
completely developed yet softer, and
starts storing iron, calcium and
phosphorus.
Week 34:
The thirty-sixth week, fetus marks
40-48cm length, weighing around
2.5to3kg, tiny hair starts vanishing,
body fat improves, fingernails attains
proper lengths, and baby born during
this week has brighter chances of
survival under medical interventions.
Weeks 35,
36, 37 & 38: The
thirty-seventh to fortieth week, fetus
takes thorough shape, measuring 48to53cm
in length, tiny hair vanished except
upper arm and shoulders, fingernails
extend beyond finger tips, small
breast-buds appear, hair on the head get
thicker and coarse. |
