1. Physiological Changes in the Pregnancy
Dr. Alia Kareem

2. Outlines of the lecture
Physiological changes in :
Blood
CVS
Respiratory system
Renal system
Endocrine
Metabolism
Skin
Reproductive organs

3. ↙ ↘ Aims Physiological changes in the pregnancy are aimed to
To maximize nutrition and oxygen to developing fetus
Help maternal system adjust to the extra stress

4. Physiological changes of the blood

5. Increase to max 40% above non pregnant level
Blood volume
Increase to max 40% above non pregnant level ↙ ↘
↑Erythrocytes mass
↑↑Plasma volume

6. The mechanisms responsible for fluid reatenasion& changes in plasma volume are unclear

7. Factors contributing to fluid retention •Sodium retention
Factors contributing to fluid retention •Sodium retention. • Resetting of osmostat. • ↓ Thirst threshold. • ↓ Plasma oncotic pressure.

8. ↓ ↓ ↓ ↑ Stoke volume ↑ Renal blood flow ↑Placental blood flow
Consequence of blood volume expanding ↓ ↓
↑↑Plasma volume>↑Erythrocyte volume
(Heamodilution)
↑ Stoke volume
↑ Renal blood flow
↑Placental blood flow ↓
↓Heamoglobuline
↓heamatocrite
↓ RBC count
↓ Albumine concntration

9. Blood cells ↓RBC count ↑WBC
Platelets count unchanged , reactivity increase, their survival is reduced in pregnancy.

10. ↓ ↓ ↓ Blood heamostasis ↓ thrombotic antithrombotic fibrinolytic
antifibrinolytic ↓ ↓ ↓ ↓
1-Plasminogen levels are increased during pregnancy
2- plasma D-dimer concentration increases progressively
-α2-antiplasmin decreased
-plsminogen activator inhibitor increased
All clotting factors
increased
-Antithrombin III levels remain unchanged
- protein S activity decreases
- activated protein C resistance increase.

11. heamatinics Iron requirement during pregnancy is increased
pregnancy without iron supplementation leads to depletion of iron stores.
plasma folate concentration decreased due to increase renal clearance of folat
red cell folate concentrations do not decrease

12. Cardiovascular system

13. functional changes
• ↑ Heart rate (10–20 per cent). • ↑ Stroke volume (10 per cent). • ↑ Cardiac output (30–50 per cent). • ↓ Peripheral resistance (35 per cent) • ↓ Mean arterial pressure (10 per cent). • ↓ Pulse pressure.

14. Ausculatory changes
1-The first heart sound is loud and sometimes split
2- a third heart sound is audible in 84 per cent of pregnant women by 20 weeks gestation.
3- An ejection systolic murmur can be heard in 96 per cent of apparently normal pregnant women.
4-diastolic murmur occurs transiently in only 20 percent of pregnant women
5- 10 per cent develop continuous murmurs due to increased mammary blood flow.

15. Anatomical changes
the heart is displaced to the left and upward and rotated somewhat on its long axis du to progressive elevation of diaphragm ,as result:
the apex is moved somewhat laterally from its usual position
causing a larger cardiac silhouette on chest radiograph .
Normal pregnancy induces slight left-axis deviation

16. Respiratory system

17. Anatomical changes
2- the diaphragm is elevated 4 cm by the enlarging uterus.
3-the lower ribcage circumference expands by 5 cm.
4- increasing the ribcage subcostal angle.

18. Functional changes Ventilation ↑ Minute ventilation. ↑ Tidal volume.
↓ERV
↓RV
↓FRC
FEV1&PEV (unchang)

19. Blood gas and acid–base changes
↓ ↓
↓ ↓ ↓
hyperventilation
↑↑Carbonic anhydrase
↓↓CO2+H2O↔H2CO3↔HCO3 + H
renal excretion
2,3-DPG
hyperventilation ↓ ←
right shift of oxyheamoglobulin dissociation curve
↑ po2

20. Blood gas and acid–base changes
• ↓ pCO2(30-50)%. • ↑ pO2. • pH alters little. • ↑ Bicarbonate excretion. • ↑ Oxygen availability to tissues and placenta.

21. Renal system

22. Anatomical changes ↑ Kidney size (1 cm).
• Dilatation of renal pelvis and ureters.
IVP of normal 35 weeks pregnancy

23. Functional changes • ↑Renal Blood flow (60–75 per cent).
• ↑ Glomerular filtration (50 per cent).
• ↑ Clearance of most substances.
• ↓ Plasma creatinine, urea and urate.
• Glycosuria is normal

24. Gastrointestinal system

25. oral Pregnancy gingivitis
Decrease in the PH& increase in protein conc. of saliva.

26. Gut Reduction of lower esophageal sphincter tone .
Increasing gastric acidity
-Delayed gastric emptying
-Prolonged gastrointestinal transit time may lead to constipation

27. LIVER
-Physical findings such as telangiectasia and palmar erythema appear in up to 60 per cent of normal pregnancies
-hepatic protein production increased
- an increase in serum alkaline phosphatase secondary to fetal and placental production is observed in pregnancy.
-s. alanine transaminase &s.aspartate transaminase shown to be lower during pregnancy,
-LDH unchanged
-the increased production and plasma levels of fibrinogen and the clotting factors VII, VIII,X and XII.
- plasma cholesterol levels rise by around 50 per cent in the third trimester and triglycerides may rise to two or three times normal levels.

28. Endocrine system

29. Pituitary gland Pitutery hypertrophy
Increase prolactine (15 folds higher than non pregnant)
Suppression of gonadotrophines

30. thyroid gland Increase in the production of thyroid binding globulin.
Increase in the total thyroid hormones.
There is a fall in TSH and arise in the fT4 in the 1st trimester.
it is followed by a fall in fT4 with advanced gestations.
Relative deficiency in the iodide.

31. ↓ ↓ ↓ Adrenal gland ↓ ↓ Increase the level of ACTH&CRH
Glucocorticoides
minrelocorticoides ↓ ↓ ↓
-↑ total cortisol
-↑Free cortisol
-Loss of diurnal variation of cortisol
Placental production of ATH&CRH
1- 10 fold increase in aldosterone & deoxycocorticosterone ↓ ↓
- Increase placental production
- Increase activiy of renin &angiotonsine
- Production of placental ACTH
-↑CBG

32. ↓ ↓ ↓ Placental hormones -GnRH ↓ -HPL steroids ostriol progesterone
Pregnancy specific
hypothalmas
pituitary
steroids ↓ ↓ ↓ ↓
-HGH
-ACTH
-PRolactin
ostriol
progesterone
-HCG
-HPL
-CRH
-GnRH

33. Human chrionic gonadotropin(HCG)
Is produced by trophoblast cells.
The B-subunit is pregnancy specific and used as a sensitive pregnancy test
maintaining the function of the corpus luteum
circulating hCG values reach peak by 10 weeks & fall off after 12 weeks

34. changes in metabolism

35. ↙ ↘ Energy requirments Pregnancy is hypermetabolic state
Additional total energy requirement is about 300 kcal/day
BMR increased by (10-20)%

36. Weight gain during pregnancy
Is consist of :
1- products of conceptions
2- increase of various maternal tissue
3- increase maternal fat stores

37. Birth weight of infant is modified by pre-pregnancy BMI
Ranges of weight gain recommended during pregnancy for women with :
Low BMI (< 20) is 12.5 kg -18 kg
Normal BMI is 11.5 – 16kg

38. Carbohydrate metabolism
In the first half of pregnancy:
1- fasting plasma glucose concentrations are reduced
2- little change in insulin levels.

39. * In the 2nd half of pregnancy: 1- an increase in glucose values
2- significant increases in plasma insulin concentrations
This suggests relative insuline resistance caused by diabetogenic hormones of pregnancy

40. Fatty metabolism
After 8th week pregnancy, there is increase in circulating concentrations of:
triacylglycerols,
fatty acids,
cholesterol
phospholipids all

41. In early pregnancy:
oestrogen, progesterone and insulin promote the accumulation of maternal fat stores in early pregnancy and inhibit lipolysis.
In late pregnancy: fat mobilization is enhanced to allow pregnant women:
- to use stored lipid for energy needs
- Minimize protein catabolism
- preserving glucose and amino acids for the fetus.

42. Calcium metabolism total plasma calcium concentrations is decrease
There is little change in the circulating concentration of unbound calcium
The fetal demand for calcium is about6.5 mmol per day
There are three methods of maternal adaptation to provide calcium in favour of developing fetus:
1- increasing gut absorption
2- mobilizing skeletal calcium reserves
3-`restricting renal losses.

43. Skin changes • Hyperpigmentation. • Striae gravidarum. • Hirsuitism.
• ↑ Sebaceous gland activity

44. Stria gravidarum
Linea nigra

45. Thank you