Download Endocrine Changes in Pregnancy

12-Mar-17
PLACENTA – Endocrine Functions
Dr. Waqas Hameed
• During pregnancy a woman’s body
undergoes a variety of changes to prepare
for the growth, nourishment, and birth of a
child.
• Health of developing fetus - closely tied to
that of the mother
PREGNANCY
contd.
• Pregnancy changes a woman’s normal
hormone patterns
• One of the first signs of pregnancy is a
MISSED MENSTRUAL PERIOD
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Maternal needs:
Safe environment for the fetus
Adequate nutrition for the fetus
Maternal changes:
↑ in maternal hormones
Production of new hormones for maternalfetal-placental unit
Adequate environment for growth &
Polypeptide hormones
development of fetus
Steroid hormones
Disposal of fetal waste products
Placenta – an endocrine organ
Human Chorionic Gonadotrophin
Estrogens
Progesterone
Human Chorionic Somatomammotropin
↑ in production of specific binding proteins
by the liver
Human Chorionic Gonadotropin
( hCG )
• From syncitial trophoblast cells
• Measured in blood after 8 – 9 days of ovulation /
fertilization ( shortly after implantation of
blastocyst)
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• Detectable in urine
• Basis of pregnancy test
• Morning Sickness
hCG
hCG
contd.
contd.
hCG
hCG
contd.
Prevents INVOLUTION of Corpus Luteum
Causes Corpus Luteum to increase
secretion of estrogen & progesterone
Effect of hCG on Fetal Testis
contd.
Regulates development of fetal testes
Stimulates Interstitial cells
Results in increased testosterone
secretion
Causes fetus to grow male sex organs
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ESTROGEN
From Syncitial Trophoblast cells
Towards end of pregnancy – Estrogen levels
are 30 times the normal levels
Estrogen
FUNCTIONS
contd.
PROGESTERONE
Enlargement of mother’s uterus
Enlargement of mother’s breast & growth
EARLY PREGNANCY
- from Corpus Luteum
of breast ductal structure
Enlargement of mother’s female external
genitalia
Relaxes the pelvic ligaments
LATER ON
- tremendous quantities from palcenta
- upto 10 fold increase
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Functions of Progesterone
Functions of Progesterone
Development of Decidual cells in uterine
contd.
Helps estrogen to prepare mother’s breast
endometrium – nutririon of early embryo
↓’s uterine contractions – prevents
for lactation
spontaneous abortion
Inhibits prostaglandin formation
↑’s secretion of Fallopian tubes & Uterus
Inhibits T-lymphocyte cell mediated
– to provide nutritive matter for Morula
rejection (prevents placental rejection)
& Blastocyst
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Human Chorionic Somatomammotropin
From 5th week of pregnancy
Secretion directly proportional to weight of
placenta
Chemically similar to Growth Hormone
Weak actions similar to Growth Hormone
Human Chorionic Somatomammotropin
contd.
Major effect on maternal glucose
- providing adequate nutrition for fetus:
Maternal Pituitary Changes
Enlarges 2-3 fold and increases in vascularity
Hyperplasia of lactotropes
Stimulates insulin release
Increase in prolactin secretion – increased
Stimulates lipolysis & free fatty acid
production and release
estrogens stimulate prolactin release, but inhibit
may lead to development of maternal insulin
resistance – thought to be responsible for
gestational diabetes
lactation until after birth
LH, FSH, & GH levels are low
ACTH appears normal
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Maternal Thyroid Changes
Maternal Adrenal Changes
Enlarges in 1st trimester
↑ Cortisol
Total T4 & T3 increases significantly
↑ in binding globulins
Increase in thyroxine-binding globulin (TBG)
↑ in production of free cortisol
due to estrogens
No signs of hypercortisolism
Free T4 and Free T3 do not change
Diurnal rhythm doesn’t change
T4 and T3 do not cross the placenta
Maternal Calcium Changes
RELAXIN
The mother must provide enough calcium for fetal
bone formation
• Ovary – Corpus Luteum
Increased intake of calcium
• Placental tissue
Increased PTH levels
Increased 1,25(OH)2D
– maternal kidney responsible for production
– placenta also produces & has specific receptors
for 1,25(OH)2D
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Maternal Body Response
• Uterus
– ↑ 50 gm to 1100 gm
• Weight Gain
– Average – 24 pounds
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•
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Fetus – 7 pounds
Uterus – 2 pounds
Breasts – 2 pounds
Blood & ECF – 2 pounds
Fat accumulation – 2 pounds
Metabolism in Pregnancy
• BMR – 15%↑ later half of pregnancy
Nutrition
IRON
• Fetus requires 375 mg iron
• Mother needs 600 mg iron
• Vitamins
• Upto 75 pounds ↑ possible !!!
Blood Volume
Respiration
• At term – 30% above normal
• 20% more oxygen requirement
• ↑ minute ventilation by 50%
• Progesterone - ↑ sensitivity of resp. centre
Urinary System
• Reabsobrptive capacity for sodium, chloride &
water - ↑ by 50%
• GFR - ↑ by 50%
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PREECLAMPSIA & ECLAMPSIA
• 5% women - ↑ blood pressure
• Protein leakage in urine
• Excess salt & water retention
• Weight gain
• Edema
ECLAMPSIA
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•
•
•
•
•
Extreme degree of Preeclampsia
Vascular Spasm
Seizures
Coma
Death
Termination of pregnancy – Cesarean section
• Hypertension
• Insufficient bld supply to placenta
Exercise
Jazak Allah
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