3. Hormones Human chorionic gonadotrophic
(β-HCG)
• Secreted from trophoblast of the developing embryo
• Maintains corpus luteum until placenta takes over
• Prevent menstruation and cause the endometrium to continue to grow and
store large amounts of nutrients
• Used in tests to confirm pregnancy
5. Hormones Estrogen
• Produced in corpus luteum
• Produced by placenta after 12 weeks
• Responsible for
1. Enlargement of the mother’s uterus
2. Enlargement of the mother’s breasts and breast ductal structure
3. Enlargement of the mother’s female external genitalia
4. Relax the pelvic ligaments of the mother
6. Hormones Progesterone
• Produced in corpus luteum and then the placenta
• Responsible for:
1. Provide nutrition to embryo by developing decidual cells
2. Inhibits uterine contractions until uterus is prepared for labour
3. Helps estrogen prepare the mother’s breasts for lactation
• Relaxes smooth muscle
• Colon activity reduced, nausea, constipation
• Diastolic pressure reduced
• Venous dilatation raises temperature
7. Hormones Human Chorionic
Somatomammotropin
• Also named as human placental lactogen
• Alters maternal metabolism
• Decreased insulin sensitivity and decreased utilization of glucose in the
mother Diverts glucose to fetus
• Mobilises free fatty acids from maternal stores
11. Weight Gain
• There is an increase weight of approximately
12.5 Kg at term
• The main increase occurs in the 2nd half of the
pregnancy 0.5 Kg/week
• Causes:
• growth of the conceptus
• enlargement of the maternal organs
• maternal storage of fat
• increase in maternal blood and interstitial
fluid
12. Changes in maternal circulatory system
• To meet increased metabolic demand.
• Increased blood volume / RBC mass
• Decreased Hct and viscosity
• Increased cardiac output
13. Effect on maternal respiration
• Because of increase metabolic rate 20% increases in oxygen demand
• Minute ventilation increases high Progesterone increase respiratory
center sensitivity to CO2
• Respiratory rate also increases due to abdominal pressure over diaphragm
14. Amniotic Fluid & Its Formation
• Amniotic fluid fluid inside uterus in
which fetus floats
• 500ml to 1lit
• Large portion derived from renal
excretion by fetus