•During Pregnancy hormones play a
significant role in triggering changes
in Mother and fetus.
~ Maintain the lining of the Uterus and
~ Prepare Mammary glands for
~ Increase flexibility of pubic
~ Affects mother’s metabolic rate and
Enhance fetal growth.
~ Determine timing of birth.
5. Hormonal regulation of Pregnancy
• During the first week after
fertilization, the ovarian corpus
luteum continues to secrete
hormones that are essential to
maintain the normal female
• After blastocyst embeds in the
endometrium it secretes
Human Chorionic Gonadotropin
6. *HCG prevents the ovarian corpus
luteum from degenerating so that
it can continue to secrete estrogen
and progesterone which act to
maintain the nourishing secretions
of the endometrial lining.
*Because of maintainance of level
of progesterone and estrogen,
menstruation does not occur.
*HCG is detectable in a woman’s
blood and urine about 8 days after
7. Hormonal regulation of Pregnancy,
• During first few months of
pregnancy, estrogen and
progesterone are secreted
primarily by the corpus luteum.
• These hormones act to maintain
nutritional support for embryo and
• HCG production increases, peaking
at 8 weeks.
• HCG triggers the corpus luteum to
produce ever increasing levels of
estrogen and progesterone.
8. By 9th week , the placenta is
the primary source of
estrogen and progesterone.
• After 4th month, levels of
HCG decrease significantly
and stay at a low level.
• Following the 4th month,
rising levels of placental
estrogen and progesterone
are sufficient to maintain
9. Hormonal regulation of
• The placenta is the
primary source of
• These hormones include;
- Human Chorionic
- Corticotropin – releasing
10. • Estrogen increase uterine blood
flow , maintaining the
endometrium during Pregnanc.
• High levels of estrogen and
progesterone inhibit the synthesis
• Progesterone inhibits contraction
of uterus to prevent premature
• Relaxin inhibits contraction of
uterus, also increases flexibility of
pubic symphysis to aid in birth
11. Human Chorionic
• hCS enhances maternal breast
growth by increasing protein
• hCS helps prepare Mammary
glands for Lactation.
* hCS increases maternal fatty
acid use for ATP production
leaving more glucose available
12. Corticotropin Releasing Hormone.
CRH stimulates the fetal
anterior pituitary glands to
ACTH stimulates fetal
cortisol , which triggers
fetal Lung maturation and
13. CRH Level increases greatly
towards the end of
Pregnancy , and stimulates
fetus and placenta to
produce more and more
Increased level of
estrogen act as timer for
birth and preparation for
It is concluded that the whole
process of pregnancy occurs under
the influence of hormone.
Hormonal regulation play an
important role in all these processes.
Imbalance of any one hormone out
of these hormones, can affect all
Hormones are regulated by Pituitary
gland of hypothalamus.