1. Maternal Physiological Changes during Pregnancy, Labor and Puerperium
ASSOCIATE PROFESSOR
IOLANDA BLIDARU
MD, PhD

2. Pregnancy is a period of adaptation for :
The needs of the fetus
Meeting the stress of pregnancy and labour

3. THE GENITAL CHANGES

4. (A) The whole uterus

5. 1 - Size
increase from 7.5 x 5 x 2.5 cm in nonpregnant states to 36 x 25 x 20 cm at term i.e. the volume increase 1000 time

7. increases from 50 gm in nonpregnant state to 1000 gm at term
2 - Weight
increases from 50 gm in nonpregnant state to 1000 gm at term

8. 3 - Shape
pyriform in the nonpregnant state , becomes globular at 8th week, then ovoid by 16th week till term .

9. 4 - Position
with ascent from the pelvis , the uterus usually undergoes rotation with tilting to the right (dextrorotation) due to the presence of the rectosegmoid colon on the left side.

10. 5 - Consistency : 2 - Presence of amniotic fluid
becomes progressively softer due to :
1 - Increased vascularity
2 - Presence of amniotic fluid

11. 6 - Contractility
from the first trimester onwards , the uterus undergoes irregular painless contractions (Braxton Hicks contractions) . They may cause some discomfort late in pregnancy and may account for false labour pain .

12. 4 ml in non-pregnant state to
7- Capacity
increases from
4 ml in non-pregnant state to
ml at term

13. (B) Myometrial changes

14. 1 - Hypertrophy (estrogen effect) + hyperplasia (progesterone effect) 2 - the fetus exerts a direct stretch

15. 2 - Formation of the lower uterine segment (L.U.S.) from the isthmus

16. Formation of lower uterine segment
After 12 weeks, the isthmus (0.5cm) starts to expand gradually to form the lower uterine segment which measures cm in length at term

17. Upper Uterine Segment Peritoneum: Firmly-attached
Myometrium: 3 layers; outer longitudinal, middle oblique (interlacing network) and inner circular.
The middle layer forms 8-shaped fibers around the blood vessels to control postpartum hemorrhage

18. Upper Uterine Segment Decidua: Well-developed
Membranes: Firmly-attached
Activity: Active, contracts, retracts and becomes thicker during labour.

19. Lower Uterine Segment
Peritoneum: Loosely-attached
Myometrium : 2 layers; outer longitudinal and inner circular.

20. Lower Uterine Segment Decidua: Poorly-developed
Membranes: Loosely- attached.
Activity: Passive, dilates, stretches and becomes thinner during labour

21. The junction between the upper uterine segment (U. U. S
The junction between the upper uterine segment (U.U.S.) which is thick and the lower uterine segment which is thin is called the physiologic contraction ring at the level of the symphysis pubis (not seen or felt)

22. (C) Uterine blood vessels

23. Uterine and vaginal blood supply

24. is doubled and its blood flow increases 5 times
1 - Uterine artery lumen:
is doubled and its blood flow increases 5 times
2 - Myometrial and decidual arteries (spiral arteries) undergo fibrinoid degeneration due to 2 waves of trophoblastic migration , so they become dilated to be the uteroplacental arteries

25. Trophoblast invasion

26. Uterine blood flow increases progressively and reaches about 500 ml / minute at term

27. (D) Changes in the cervix :
1 - It becomes hypertrophied , soft and bluish in colour due to oedema and increased vascularity.

28. 2 - Soon after conception, a thick cervical secretion obstructs the cervical canal forming a mucous plug .
3 - The endocervical epithelium proliferates and / or everts forming cervical ectopy (previously called erosion) (sometimes).

29. Cervical eversion (colposcopy)

30. 4 - There are 3 principal structural components of the cervix: smooth muscle (only 10%), collagen and connective tissue or extracellular matrix (ground substance).

31. 5 -The cervical ripening process - changes in collagen (breakdown and rearrangement of the fibers), connective tissue and its ground substance (alterations of the various glycosaminoglycans).
6 - In the ripening of uterine cervix there are involved: PG E2 and PG F2 alpha, E, P and relaxin.

32. (E) Changes in fallopian tubes and round & broad ligaments :
Inactive , elongated , marked increase in vascularity
There may be broad ligament varicose veins

33. (F) Changes in the vagina :
The vagina becomes soft , warm , moist with increased secretion and violet in colour (Chadwick's sign) due to increased vascularity

34. (G) Changes in the vulva :
It becomes soft, violet in colour
Oedema and varicosities may develop

35. (H) Changes in the ovaries
1 - Both ovaries are enlarged due to increased vascularity and oedema particularly the ovary which contains the corpus luteum .

36. (H) Changes in the ovaries
2 - Corpus luteum continues to grow till weeks, then it stops growing.
It becomes inactive and starts degeneration at 12 weeks (degeneration is completed after labour)

37. Corpus luteum secretes
1.estrogen 2.progesterone
3.relaxin
hormones

38. (H) Changes in the ovaries
3 - Ovulation ceases during pregnancy due to pituitary inhibition by the high levels of oestrogen and progesterone

39. Relaxin is a protein hormone.
Its complete role in pregnancy is debated.
It may induce softness and effacement of the cervix.

40. II - Haematological Changes

41. (A) Blood volume
The total blood volume increases steadily from early pregnancy to reach a maximum of % above the non-pregnant level at 32 week .

42. After delivery, it decreases rapidly by 600-800ml.
Plasma volume :
Increases from 2600 ml by ± 45 % (1200 in the 1st pregnancy) and 1500 ml in subsequent pregnancies
After delivery, it decreases rapidly by ml.

43. The increase is steady till full term.
Red blood cell mass :
Increases from 1400 ml (nonpregnant) by 30 % (± 450 ml) due to increased production resulting from erythropoietin action
The increase is steady till full term.

44. The increase in plasma volume is more than the increase in red blood cell mass (Hb mass) resulting in haemodilution
(physiologic anemia)

45. However, the minimal Hb. accepted is
10-11 gm%

46. Changes in the blood volume

47. Values of increased blood volume
1 - Meets increased demands for uterus, baby .... etc.
2 - Protects against supine hypotension syndrome.
3 - Protects against fluid loss at delivery.

48. Increased blood volume more than the increase in red cell mass, leads to decreased blood viscosity which leads to a decrease in peripheral resistance

49. (B) Blood indices

50. 1 - Decreased Hb % and RBCs % :
Erythrocytes decrease from 4.5 million / mm3 to 3.7 million / mm3 (due to the relative increase in plasma volume more than red cell mass).

51. Hb concentrations falls
from 14 g / dl To
12 g / dl.

52. (Erythrocyte Sedimentation Rate )
2 - Reticulocytes : mild 
3 - E.S.R : from 12 to 50 mm / hour
(Erythrocyte Sedimentation Rate )
4 – Fibrinogen:  from mg / dl to mg / dl.

53. All these changes are reversed after labour with  RBCs production (not  destruction) & the excess Fe is stored .

54. 5 - White blood cells:
(from / mm3 to / mm3 during pregnancy and up to / mm3 during labour.
6 -  PNL & its enzymes.
(Polymorphonuclear Neutrophilic Leukocyte)
7 - Lymphocytes: no change.

55. 9 -Total plasma proteins: slightly 
8 - Platelets: 
9 -Total plasma proteins: slightly 
(mainly  albumin) resulting in  osmotic pressure.
10 - Increased plasma lipids

56. (C) Coagulation system

57. Platelets , unchanged adhesivity.
Fibrinogen doubled to 600 mg %
Factor VIII tripled .
Factor VII & factor X doubled
Factor XI & factor XIII slight 
Fibrinolytic activity .

58. Therefore pregnancy is a hypercoagulative state.
After delivery, fibrinogen and plasminogen decrease and the fibrinolytic activity in the plasma increases.

59. Ill - Cardiovascular system changes

60. (A) Changes in the heart

61. Position:
As the diaphragm is elevated progressively during pregnancy the apex is displaced upwards and to the left so that it lies in the 4th intercostal space outside the midclavicular line.

62. Pulse rate : The resting pulse rate increases by 8 beats / min.
at 8 weeks and 16 beats / min. at full term.
- Some episodes of ectopic beats

63. Heart sounds
The first heart sound become louder before midpregnancy and splitting of this sound may occur due to earlier closer of the mitral than the tricuspid valve
The intensity of the second heart sound may increase.

64. Heart sounds
The third sound becomes louder before mid-pregnancy and persists as such till one week post partum.
The fourth sound may be detectable by phonocardiography.

65. Murmurs Systolic functional murmurs
develop in most of women, usually early systolic, but mid systolic murmurs may occur and heard over the left sternal edge,
they are thought to be due to functional tricuspid regurgitation

66. ECG CHANGES
The main features of ECG may be attributed to the changes in the position of the heart.
The axis undergoes left shift by °.
The QRS complexes become of low voltage, and T wave becomes flattened.

67. (B) Haemodynamic changes

68. 1 - Cardiac output (C.O.P.)

69. Cardiac output = stroke volume x heart rate
increases mainly by increased stroke volume rather than increased heart rate reaching a maximum of 40% above the non-pregnant level at 20 weeks to be maintained till term.
Cardiac output = stroke volume x heart rate

70. Cardiac output Distribution : 400 ml to the uterus,
300 ml to the kidneys,
300 ml to skin,
300 ml to gastrointestinal tract, breast & heart

71. During labour: Roles: Distributes extra 02
Cardiac output increases more particularly during the second stage due to pain , uterine contractions, and expulsive efforts pushing the blood into the general circulation

72. Postpartum :
the increased CARDIAC OUTPUT is maintained for up to 4 days and then declines rapidly

73. 2 - Arterial blood pressure

74. Although CARDIAC OUTPUT increase, yet Arterial Blood Pressure is decreased in midtrimester to increase again in 3rd trimester

75. 1- Decreased Peripheral resistance :
This is due to:
1- Decreased Peripheral resistance :
(mainly affect diastolic B.P.) due to : vasodilatation + increased metabolism + arterio-venous shunt at the level of placenta .

76. 2.- Supine hypotensive syndrome:
may develop in late pregnancy while lying supine  compression on the Inferior Vena Cava by the large pregnant uterus  decreased venous return  decreased Cardiac Output and low B.P. to the extent that fainting may occur.
Treatment: lateral recumbent position

77. Vena Cava Syndrome

78. 3. - Decreased sensitivity of blood vessels to angiotensin II which is vasoconstrictor

79. The posture of the pregnant woman affects arterial blood pressure.
Typically, it is highest when she is sitting, lowest when lying in the lateral recumbent position and intermediate when supine.

80. Peripheral Vasodilatation

81. Peripheral Vasodilatation
Regional blood flows
- the utero-placental flow,
- the renal blood flow,
- the skin, particularly in the hands and feet + mammary gland

82. Peripheral Vasodilatation
 Renal blood flow → glomerular filtration increase favoring the oxygen supply and the amplification of some active processes.
The increase of glomerular filtration contributes to the explanation of glycosuria, aminoaciduria and to the increase of water-soluble vitamin excretion.

83. Peripheral Vasodilatation
blood flow to the skin, particularly in the hands and feet generally giving the pregnant women a feeling of warmth

84. Peripheral Vasodilatation
Increases the congestion of nasal mucosa leading to a common complaint of nasal obstruction and bleeding (epistaxis).

85. 3 - Venous pressure

86. Increased venous pressure in the lower limbs due to:
1. Back pressure from the compressed Inferior Vena Cava by the pregnant uterus .
2.Mechanical pressure of the uterus on pelvic veins .
3.Increased venous return from internal iliac veins → increased pressure in external iliac veins .

87. Increased venous pressure in the lower limbs
Predisposes to:
Oedema,
varicose veins
and piles

88. Oedema and varicose veins in the lower limbs & vulva are due to
1. -  Venous pressure.
2. - Relaxation of the smooth muscles in the wall of the veins by progesterone
3. -  Osmotic pressure in blood.
4. -  Capillary permeability (due to progesterone and aldosterone).
5. -  Interstitial pressure (Na retention).

89. IV - Respiratory system

90. The enlarged uterus displaces the diaphragm up to 4 cm .
(A) Anatomically:
The enlarged uterus displaces the diaphragm up to 4 cm .

91. This results in :
1. The diaphragmatic mobility is reduced and respiration becomes mainly thoracic.
2. Widen the subcostal angle and increases the transverse diameter of the chest.

92. Respiratory functions
The respiratory rate
does not increase during pregnancy from its normal rate of / minute.

93. occurs due to the effect of excess progesterone
Overbreathing
(deep respiration)
occurs due to the effect of excess progesterone

94. (the need to breath becomes a conscious one)
Shortness of breath
(the need to breath becomes a conscious one)
and dyspnea are common complaints of the pregnant women which may be due to unfamiliarity with low C02 tension in the alveolar capillaries .

95. The vital capacity 1.The inspiratory capacity
(Tidal volume + inspiratory volume)
is decreased in late pregnancy

96. 2.The expiratory reserve volume
(maximum amount of air which can be expired after normal expiration) is reduced
3.The residual volume
is reduced .

97. The reduction in: is not significant. 1.The inspiratory capacity
2.The expiratory reserve volume
3.The residual volume
is not significant.

98. 4.The tidal volume :
(amount of gas inspired or expired in each respiration) rises through­out pregnancy by about 40 % .

99. Hyperventilation is due to increased tidal volume not respiratory rate
►a respiratory alkalosis takes place

100. V - Urinary system

101. (A) Kidney and kidney function tests
Renal blood flow and glomerular filtration rate increases by 50 %.
This leads to increased excretion

102. Blood Tests:
There is  serum creatinine (due to  creatinine cleareance)
 serum uric acid.
3.  blood urea.
4.  kidney excretion of glucose is due to  filtration load and  renal threshold leading to renal glucosuria.

103. Therefore , in interpretating the results of kidney function test you should take into consideration that
the lowest normal values in non-pregnant state = the highest normal values in pregnancy

104. Dilatation of the ureters and renal pelvis due to:
(B) Ureters
Dilatation of the ureters and renal pelvis due to:
1.Relaxation of the ureters by the effect of progesterone.
2. Pressure against the pelvic brim by the uterus particularly on the right side due to dextroposed uterus and dilatation of the right ovarian vessels

105. (C) Bladder and urethra
Frequency of micturition
in early pregnancy due to:
- Pressure on the bladder by the enlarged uterus.
- Congestion of the bladder muscosa.

106. VI - Gastrointestinal tract & liver

107. 1 - Gingivitis :
There is increased vascularity and tendency for bleeding as well as hypertrophy of the interdental papillae

108. Treated by dental hygiene and cryosurgery for severe cases.
The gums may become hyperemic and soft and may bleed when mildly traumatized, as with a tooth brush.
Epulis of pregnancy
may develop.
Treated by dental hygiene and cryosurgery for severe cases.

109. 2 - Ptyalism:
It is excessive salivation which is more common in association with oral sepsis .
It is due to failure to swallow saliva and not due to increase in amount.
Smoking is stopped and anticholinergic drugs may help.

110. Nausea (morning sickness)
3 - Nausea and vomiting
Nausea (morning sickness)
and vomiting
(emesis gravidarum)
occur in early months

111. 4 - Appetite changes (longing or craving)

112. The pregnant woman dislikes some foods and odours while desires others
Reduced sensitivity of the taste buds during pregnancy creates the desire for markedly sweet, sour, or salt foods .

113. (pica)
Deviation may be so extreme to the extent of eating blackboard chalk, coal or mud

114. 5 - Indigestion and flatulence

115. This is probably due to :
1. - Decreased gastric acidity caused by regurgitation of alkaline secretion from the intestine to the stomach .
2. - Decreased gastric motility (progesterone effect).

116. Due to reflux of acidic gastric contents to the oesophagus
6 - Pyrosis (Heart burn)
Due to reflux of acidic gastric contents to the oesophagus

117. The treatment includes :
(a) small frequent meals to prevent overdistension of the stomach. The evening meal should be taken at least 3 hours before going to bed.

118. (b) avoid fatty foods, chocolate, and smoking, as these relax the lower esophageal sphincter.
(c) the bed should be raised at the head (15-20 cm), and an extra pillow is used.

119. (d) Antacid Preparations containing aluminium hydroxide are favoured.

120. 7 - Constipation
Due to:
1. - Reduced motility of large intestine (progesterone effect).
2. - Increased water reabsorption from large intestine (aldosterone effect).

121. 7 - Constipation
3. - Pressure on the pelvic colon by the pregnant uterus.
4. - Sedentary life during pregnancy .

122. (a) evacuation of the bowel at the same time each day (bowel training)
It is treated by
(a) evacuation of the bowel at the same time each day (bowel training)

123. (b) diet rich in fiber in the form of vegetables, fruits, and bran
(c) milk and avoid dehydration by increasing fluid intake.

124. (d) minimize coffee and tea as they are diuretics and cause dehydration.
(e) increase physical activity and avoid sedentary life.

125. (f) a mild laxative may be needed.
Liquid paraffin is better avoided as it prevents absorption of fat soluble vitamins.

126. In some women iron supplementation may be the cause

127. 8 - Gall stones
More tendency to stone formation due to atony and delayed emptying of the gall bladder

128. 9 - Haemorroids

129. due to :
1. - Mechanical pressure on the pelvic veins.
2. - Laxity of the walls of the veins by progesterone
3. - Constipation.

130. 10 - Appendix
Is displaced upwards and laterally (pain and tenderness due to appendicitis is higher than in nonpregnant state)

131. Appendix

132. Liver 2. - Increased heat labile serum alkaline phosphatase .
1. - Decreased albumin and increased globulin resulting in decreased A/G ratio
2. - Increased heat labile serum alkaline phosphatase .

133. The functional disorders are minimal.
Therefore both A/G ratio and heat labile alkaline phosphatase are not reliable as liver function tests during pregnancy
The functional disorders are minimal.

134. VII - Metabolic changes

135. The average weight gain in pregnancy is
(A) Weight gain
The average weight gain in pregnancy is kg

136. The increase occurs mainly in the second and third trimester at a rate of 350 - 400 gm/ week

137. Out of the 11 kg weight gain
6 kg is composed of maternal tissues (breasts, fat, blood and uterine tissues), and
5 kg of fetal tissue, placenta and amniotic fluid

138. Maternal Tissues Increases during weeks of Pregnancy
King JC. Am J Clin Nutr 71 (5(S));2000.

139. Products of Conception Increases during weeks of Pregnancy
King JC. Am J Clin Nutr 71 (5(S));2000.

140. Out of the 11 kg weight gain:
7 kg are water,
3 kg fat and
1 kg protein

141. There is tendency to water retention secondary to sodium retention
)B) Water metabolism
There is tendency to water retention secondary to sodium retention

142. (C) Protein metabolism
There is tendency for nitrogen retention
(+ nitrogen balance) for fetal and maternal tissue formation

143. (D) Carbohydrate metabolism
Pregnancy is potentially diabetogenic
- Alimentary glucosuria may occur in early pregnancy.
- Renal glucosuria may occur in the middle of pregnancy.

144. (E) Fat metabolism
There is increase of plasma lipids with tendency to acidosis (Human Placental Lactogen action)

145. (F) Mineral metabolism
There is increased demand for iron, calcium, phosphate and magnesium

146. IX - Endocrine system

147. 1 - Anterior pituitary

148. 1. - Increase in size more than increase in vascularity
This renders anterior pituitary liable for ischaemia.

149. 3. The ACTH and MSH secretion increases.
2. - Prolactin level increases up to 150 ng /ml at term to ensure lactation.
3. The ACTH and MSH secretion increases.

150. Does not hypertrophy, but increase its oxytocin release near term.
2 - Posterior pituitary
Does not hypertrophy, but increase its oxytocin release near term.
OXT is synthesized in the hypothalamus (supraoptic and paraventricular nuclei).

151. There is diffuse slight enlargement of the gland
3 - Thyroid gland
There is diffuse slight enlargement of the gland

152. Gland activity is  as evidenced by normal free T4 (although total T4 ) due to  thyroid binding globulin (TBG) ,
Basal Metabolism Rate (20 %),  total T3, protein bound iodine and TSH

153. Hypertrophy due to increased demand for Calcium
4 - Parathyroid gland
Hypertrophy due to increased demand for Calcium

154. 5 - Suprarenal gland
Hypertrophy particularly the cortex resulting in increased glucocorticoids (cortisone) and increased mineralocorticoids (aldosterone)

155. 5 - Suprarenal gland
Under the influence of estrogens, transcortin (cortisol-binding globulin) levels rise and, together with cortisol, produce a slight hypercorticism.
As early as 15 weeks of normal pregnancy, the maternal adrenal secretes considerably increased amounts of aldosterone.

156. increased mainly due to HPL (anti - insulin hormone)

157. 7 -Ovaries corpus luteum of pregnancy
functions till 8-12 wks. when its function is taken by the placenta

158. Due to melanocyte stimulating hormone
4 - Pigmentation
Due to melanocyte stimulating hormone

159. In the face = chloasma gravidarum = mask of pregnancy
a butterfly pigmentation on the cheeks and nose.
It usually disappears few months after labour.

160. Linea nigra

161. Linea Nigra= pigmentation in midline below the umbilicus
In abdomen:
Linea Nigra= pigmentation in midline below the umbilicus

162. pigmentation in the lower abdomen ,
Stria gravidarum
pigmentation in the lower abdomen ,
flanks , inner thighs , buttocks & breast and increase as pregnancy advances

164. It starts bluish (stria rubra) , then becomes pale to become white (stria albicans) after delivery , which persists (primigravida has stria rubra only, while multigravida has both S.R and S.A)

165. It is due mainly not to mechanical stretching but to increased glucocorticoids which results in rupture of the elastic fibres in the dermis and exposure of the vascular subcutaneous tissues

166. increase in sweat and sebaceous glands activity
5 - Secretions
increase in sweat and sebaceous glands activity

167. (B) Breast signs

168. Breast changes

169. 1. – Early pregnancy :
increased size & vascularity (dilated veins), mastodynia may be present which ranges from tingling to frank pain due to hormonal responses of the mammary ducts and alveolar system

170. enlarged sebaceous glands
2. – end of I trim. :
increased pigmentation of the nipple & areola and prominence of Montgomery tubercles - nonpigmented nodules around the primary areola ( )
enlarged sebaceous glands

171. 3. - Midpregnancy:
secretion of colostrum (thick yellowish fluid) which can be expressed from the nipple

172. 4. - Midpregnancy:
a pigmented area appears around the primary areola called the secondary areola

173. XII. Neurologic System

174. 1. Headache
It is relatively common, and attributed to intracranial vasodilatation caused by oestrogen and progesterone

175. 2. Fainting
It results from lowering of blood pressure due to vasodilatation which occur in pregnancy

176. 3. Insomnia
During pregnancy some women are sleepy and depressed, others may be irritable and suffer insomnia

177. LEUCORRHEA
The normal vaginal discharge increases during pregnancy because of excess oestrogen and may form a complaint

178. However, a pathological discharge, e. g
However, a pathological discharge, e.g., monilial infections which is common in pregnancy must be excluded.