The document summarizes the key stages of prenatal development from conception through birth in 3 months. During the first month, the zygote forms and begins cell division. In the second month, the embryo develops organs and the placenta forms. The third month sees further development of features and organs. The fetal period in months 4-9 sees continued growth and maturation of all body systems. By the end of the 9 months, birth occurs and development is complete.

1. BANARAS HINDU UNIVERSITY
FACULTY OF EDUCATION
PRESENTED BY
KORI AKASH MILAN
1.
KALPANA TIWARI
2.
SAMANA GUPTA
3.
NEERAJ YADAV
4.
KUNAL BANSAL
5.
PRENATAL DEVELOPMENT
PRESENTRD TO
DEAN FACULTY OF EDUCATION
DR.ANJALI BAJPAI MA'AM

2. Prenatal Development
prenatal development, in
humans, the process
encompassing the period from
the formation of an embryo,
through the development of a
fetus, to birth (or parturition)

3. GAMETE FORMATION

4. conception
Conception occurs when a sperm cell penetrates and
fertilizes an egg cell
egg cell migrates most of
the way down the
fallopian tube
One sperm must
penetrate the ovum to
form a zygote

5. Stages Of Prenatal Development

6. Germinal Period
Happens 2 weeks after conception
includes:
Creation of zygote ;
Continued cell division; and
The attachment of the zygote to the uterine wall
Rapid cell division (Zygote - Morula - Blastula -
Gastrula - Embryo)
By the end of the stage,the fertilized egg becomes a
blastocyst and plant itself in the wall of utreus

9. Germal Stages

10. EMBRYONIC PERIOD
The period from implantation to about the
eighth week after conception.
During the embryonic stage, the germ layers
appear, become more organized and begin to
form the early structures of the body.
Life support system for the embryo develop
Organs start developing (Organogenesis)

11. At the end of four weeks:
-Embryo is 1/4 inch in length
-Heart beat, digestive system, backbone and spinal cord begin to form
-Placenta (sometimes called "afterbirth") begins developing
-The single fertilized egg is now 10,000 times larger than size at conception
At the end of 8 weeks:
-Embryo is 1 1/8 inches in length
-Eyes, nose, lips, tongue, ears and teeth are forming
-Embryo is moving, although the mother can not yet feel movement
-Heart is functioning

12. The placenta is an organ that develops in the uterus during
pregnancy. This structure provides oxygen and nutrients to a
growing baby. It also removes waste products from the baby's
blood. The placenta attaches to the wall of the uterus, and the
baby's umbilical cord arises from it.
Cord blood contains stem cells. These are cells that can grow
into specific kinds of cells in your body. Stem cells may be
used to treat some diseases, like some forms of cancer and
anemia.
The amnion is a membrane that closely covers the human
and various other embryos when first formed. It fills with
amniotic fluid, which causes the amnion to expand and
become the amniotic sac that provides a protective
environment for the developing embryo. The amnion, along
with the chorion, the yolk sac and the allantois protect the
embryo.
life support system of baby

13. 1ST MONTH (4 WEEKS) 6 WEEKS 7 WEEKS 8 WEEKS
2ND MONTH(8 WEEKS)

14. FETAL PERIOD
2 to 9 months after conception
Growth and development continue
dramatically during this period From 9 weeks
after conception to birth.
The most dramatic stage
Increase in size and systems begin to function
Age of viability : 24-28 weeks
Although all of the organ system were formed
during the embryonic development, they
continue to develop and grow during the fetal
stage.

15. The first trimester will span from conception to 12
weeks. This is generally the first three months of
pregnancy. During this trimester, the fertilized egg will
change from a small grouping of cells to a fetus that
begins to have human features. The first trimester is
exciting, but also when most people develop unpleasant
symptoms like morning sickness and fatigue.
First Trimester

16. First Month (Weeks 1st - 4th)
After an egg has been fertilized and implants
into the uterine lining, a sac grows around it
This becomes the amniotic sac and will hold
the amniotic fluid and cushion the embryo.
The placenta also forms during this month.
This will bring nutrition and support to the
baby from the mother
The face and eyes begin to develop, and the
heart begins to beat. By the end of the 4th
week, the baby will slightly smaller than a
grain of rice!
B vitamins play a crucial role in you and your
baby’s development and your health during
pregnancy. Vitamin B6 and Folic Acid
(Vitamin B9)

17. Second Month (Weeks 5th - 9th)
At two months pregnant, your baby’s face
continues its development.
Buds that will eventually be limbs begin to
develop.
Organs such as the brain, sensory organs,
and the digestive tract begin to take shape.
The cartilage in the embryo begins to be
replaced by bone. By the end of the
second month, your baby is about 1 inch
long!
After about 6 weeks, your baby’s
heartbeat can be detected with an
ultrasound.

18. The limbs, as well as the hands, feet, fingers, and
toes, become well developed.
The fingernails and toenails begin to form.
The external ears and teeth begin their
development as well.
Though reproductive organs haven begun to
form, they can’t yet be determined on an
ultrasound or sonogram.
By the end of the 3rd month, your baby is fully
formed (with all organs and extremities present),
he or she weighs about an ounce and is 4 inches
long!
After the 3rd month of development, the chance
of miscarriage drops considerably.
Third Month (Weeks 10th - 14th)

19. The second trimester of pregnancy is often thought of
as the best part of the experience. By this time, any
morning sickness is probably gone and the discomfort of
early pregnancy has faded. You may also start to feel
movement as the fetus flips and turns in your uterus.
During this trimester, many people find out about the
fetus’s assigned sex. This is typically done during an
anatomy scan (an ultrasound that checks physical
development) at around 20 weeks.
Second Trimester

20. Hair, eyelids, eyelashes, and nails become well developed.
The heartbeat is now clearly audible through a Doppler
instrument.
The teeth become denser, and the baby begins to stretch,
yawn and make other movements.
The reproductive organs are now visible on an
ultrasound. The baby can now stretch, suck their thumb,
yawn, and make super cute faces.
This is the month that his or her nervous system
develops.
Their reproductive system also fully develops meaning
your doctor can tell you whether you are having a girl or
boy via ultrasound.
By the end of the 4th month, your baby is about 6 inches
long and weighs 4 ounces!
Fourth Month (Weeks 15th - 19th)

21. Fifth Months (Weeks 20th - 24th)
This month you may start to feel the baby
move.
Hair growth continues on the baby’s head and
body.
The shoulders and back become covered with a
thin hair called lanugo.
A thick substance, called vernix caseosa, covers
the skin to keep it protected from the exposure
to amniotic fluid. This layer will shed before the
baby is born.
At the end of month 5, your baby is about 10
inches long and can weigh anywhere from .5 lbs
– 1 lb!

22. Sixth Months ( Weeks 25th - 30th)
The skin is still translucent yet reddish
and wrinkled.
His or her fingerprints and toe prints
become well developed.
The baby’s eyelids become parted, and
the eyes can be opened.
The baby will respond to external stimuli
such as sounds by increasing their pulse or
moving. This is when you may experience
your baby’s hiccups in jerk-like motions.
At the end of month 6, your baby is about
12 inches long and can weigh close to 2 lbs!

23. Third Trimester
This is the final part of pregnancy. You may be
tempted to start counting down the days to your
due date and hope that it comes early, but each
week of this final stage of development helps
the fetus prepare for birth. Throughout the
third trimester, the fetus gains weight quickly,
adding body fat that’ll help after birth.

24. During this month, your baby will continue to
grow and develop the existing organs and
systems.
In addition, a layer of fat will begin to be stored.
At this stage, hearing is fully developed.
He or she will react to sound, pain, and light
and often changes position
The amount of amniotic fluid that cushions the
baby begins to decrease as the baby grows
larger.
At the end of this month, your baby is about 14
inches long and can weigh between 2 – 4 lbs!
If born prematurely after week 27, your baby
has a better chance of survival.
Seventh Months (Weeks 26th -29th)

25. The baby continues to mature during
this month, adding to fat stores and
experiencing a rapid development of
the brain.
The baby can see at this stage and will
begin to kick more.
Most of the internal organs and
systems are fully developed, but the
lungs still need time to mature.
By month 8, the baby is close to 18
inches long and can weigh close to 5
Eighth Month (Weeks 30th - 34th)

26. The lungs become mature during this
time in preparation for birth.
Reflexes become more coordinated,
allowing the baby to respond to
sounds, blink, grasp, and turn his or
her head.
The baby may move less during the
last few weeks and will move into a
position for birth, with the head down
near the birth canal.
baby is now about 18-20 inches long
and can weigh at least 7 lbs!
Ninth Months ( Weeks 35th - 38th)

27. Journey Completed

28. Not alone is the child born through the mother, but the
mother also is born through the child.
-Gertrud von Le Fort

29. REFRENCES
https://americanpregnancy.org/healthy-pregnancy/week-by-
week/baby-development-month-by-
month/#:~:text=Month%201%20%E2%80%93%20Week%201
%2D4&text=The%20placenta%20also%20forms%20during,th
an%20a%20grain%20of%20rice!
https://my.clevelandclinic.org/health/articles/7247-fetal-
development-stages-of-growth
https://www.slideshare.net/channshann/pre-natal-
development
NCERT 12TH CLASS BIOLOGY

30. Thank you!