The document summarizes the stages of pregnancy from conception through birth in three trimesters. It describes the key developments that occur with the fetus each week and the maternal physiological changes that take place to support the growing fetus. The major stages are conception and fertilization, formation of the three germ layers in the first few weeks, major organ development in the first trimester, bone growth and skin development in the second trimester, lung and brain maturation in the third trimester, and final preparation for birth at full-term between 37-40 weeks.

1. STAGES OF
GESTATION

3. PREGNANCY
• Pregnancy is also known as gestation, is the
time during which one or more offsprings
develops inside a women.
• A multiple pregnancy involves more than
one offspring , such as twin .
• Pregnancy can occur by sexual intercourse.

5. PRENATAL
• 280 days
• 40 weeks
• pre =“before”
• Natal=“ relating to birth”
• Development of a baby
during the period before birth.

6. Productive cells
• Male= sperm produced in testes.
• Female =egg or ovum produced in the
ovaries.

8. • Fallopian tube:
• Hollow tubes that extend from the right and
left sides of the uterus.
• Where fertilisation takes place.

9. Uterus (womb)
• Organ where baby develops and is
protected.
• The size of the uterus pre-pregnancy is
about the size of lemon.
• Conception:
• The joining of egg and sperm. This is where
hereditary trait is determined .
• Also referred as fertilisation.

10. GERMINAL STAGE
• Germinal stage starts with conception.
• First two weeks of pregnancy comes under
this stage .
• AMNION: Fluid filled with sac that
surrounds the baby in uterus.
• YOLK SAC : These provides nutrients
before the placenta takes over.

12. ZYGOTE
• This is formed when the egg and the sperm
unite and begin to develop.
• Each person has 46 chromosomes.
• 23 from mother
• 23 from father

13. SEX DETERMINATION
• Determined at the time of conception
• Female =X
• Male= XorY
• XX= girl XY=boy
• Father can only determine the sex of the
baby.

15. FIRST TRIMESTER
• Early pregnancy (1-3 weeks).
• Most critical stage because all major organs
begin to form.
• GERMINAL STAGE /PRE-EMBRYONIC
STAGE
• The germinal stage is the prenatal,
developmental stage that begins at
fertilation and lasts through the second
week.

16. • The fertilized egg/ovum makes it way down
the fallopian tube , and begins to have cell
reproduction .
• The single celled zygote becomes a
multicelled ball that attaches itself to the
wall of the uterus around the end of the
second week , which consitutues the
beginning of the embroyonic stage .

18. LAYERS OF BLASTOCYST
• 1. ECTODERM(upperlayer)
This will become the outer layer of
skin,the nails,the hair,the teeth,the sensory
organs and the nervous system including the
spinal cord and brain.
2. MESODERM(middle layer)
Inner layer of skin ,muscles,skeleton
and bonemarrow,heart and blood
corpuscles,bloodvessels,kidney and gonads.

19. • 3. ENDODERM(innerlayer)
These will develop the linings of nearly
all of the internal organs,including those of
the lungs,trachea and pharynx and digestive
tract including the pancreas and the liver.

21. • Nearly all defects and abortions occur
during the critical first trimester of
pregnancy.
• Important dangers include improper
maternal nutrition ,medical x-rays ,and
external environmental hazards .
• Baby receives good and harmful substances
through mother’s umblical cord.

22. • The heart beat can usually be seen around 6
weeks via ultrasound.
• PLACENTA
organ filled with blood and vessels that
nourishes the baby in the uterus.
• UMBLICAL CORD
connects the baby to placenta , nourishes
baby and removes waste.

24. SECOND TRIMESTER
• Week 13- Week 28
• The Musculoskeletal system continues to
form
• skin begins to form.
• Meconium develops in baby’s intestinal
tract.
• Baby is about 4 to5 inches long and weighs
about 3 ounces
• 3 ounces=0.0850486 kg

25. • About 20 weeks baby continues to develop
• Baby is active, and baby is protected with
feathery hair called lanugo and a waxy
protective coating called vernix.
• Eyebrows, eyelashes,fingernails,toenails
have formed .
• Baby can hear and swallow .
• Baby is about 6 inches and 9
ounces=0.255146

27. • By 24 weeks, even more changes occur
,baby’s bone marrow begins to make blood
cells.
• Taste buds forms on baby’s toungue.
• Footprints and fingerprints have formed .
• If baby is boy, his testicles to descend into
the scrotum.
• If baby is girl ,her uterus and ovaries are
placed.

28. • Baby stores fat and weight about
1.5pounds,is 12 inches long.
• THIRD TRIMESTER
• Week 29-Week 40 (32 weeks)
• Baby bones are soft but fully formed
movements and kicking increases.
• Eyes can be opened and closed .

29. • Lungs can able to practice breathing.
• Baby will gain about half pound a
week,weighs about 4 pounds to 4.5 pounds.
• 15-17 inches long
• At 36 weeks due date approaches baby
continues developing .
• Baby fat increases ,and has less space to
move around .movements are less freeful.

30. • Baby is about 16-19 inches long and weighs
about 6 to 6.5 pounds.
• Finally from 37to 40 weeks the last stage of
baby’s develpoment occur:
• End of 37 weeks is considered as full term
• Baby’s organ are capable of functioning
their own .
• As near due date baby may turn into a head
–down position for birth.

32. • Average birth weight is about 12 to 19
inches and
• 9 pounds and2 ounces=4.139030376250001
kg
• Most fullterm babies fall within these
ranges

34. MATERNAL PHYSIOLOGICAL CHANGES
• Pregnant women undergoes to
accommodate the growing embryo or fetus.
• They increase in blood sugar ,breathing,
cardiac output are all expected changes
that allow a pregnant women’s body to
facilitate proper growth and development of
the embryo and fetus during the pregnancy.

35. • Progestrone and estrogen levels rise
continually through pregnancy ,together
with blood sugar , breathing rate and
cardiac output.
• The body posture changes during
pregnancy.
• Mother will experience weight gain.
• Breasts grow and change in preparation for
lactation .

37. MATERNAL CHANGES
• Changes in weight
• Hormonal changes
• Increase in total blood volume
• Increase in fetus size.
• Estrogen and progesterone are
major hormones during pregnancy.