everything about pregnancy

1. Physiology of
Pregnancy
Santosh mohle
BNYS
SVYASA
Sep 18, 2012 1

2. Sep 18, 2012 2

3. INTRODUCTION
Pregnancy
The course that the embryo and the fetus
grow in the maternal body
Stages of pregnancy
1.Early pregnancy: ≤12 weeks
2.Mid pregnancy: ≥13 weeks,≤27 weeks
3.Late pregnancy:≥28 weeks
4.Term pregnancy:≥37 weeks,<42 weeks
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4. Normal pregnancy average duration is
counting from first day of last menstrual
period is about 280 days and 10 lunar
months or 40 weeks
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5. Formation of Embryo
A. Fertilization
Fusion of male & female gamates to form
a zygote
1. Place: oviduct (ampulla)
2. Process
capacitation → acrosome reaction→
penetrate the zona pellucida→
second meiosis →zygote
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6. Fertilization
Fertilization in the
ampulle of the FT.
Prostaglandins
• Oxytocin
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7. Contd…
B. Implantation
1)Disappear of zona pellucida
2)Formation of syncytiotrophoblast
3)Synchronized development of
blastocyst and endometrium
4)Adequate progesterone
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8. Contd…
Process
1) morula (day 3) → enter uterine
cavity (day 4) → early
blastocyst→ late blastocyst
(day 6-7) → implantation
2) location→ adherence→
penetration
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9. Fertilization
Implantation 5-7
days after
fertilization
• Proteolytic enzymes
of the trophoblast
cells
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10. Development of embryo and fetus
Definition
1.embryo: ≤ 8 weeks
2.Fetus: ≥ 9 weeks, human shape
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11. Development of embryo and fetus
Physiology of fetus
A.Circulation
1)fetus ←→placenta←→ mater
2)1 umbilical vein (full of oxygen),
2 umbilical artery (lack of oxygen)
3)Mixed blood (vein and artery)
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12. Development of embryo and fetus
B. Hematology
1) Erythropoiesis
From yolk sac: 3 weeks
From liver: 10 weeks
From bone marrow and spleen:
term (90%)
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13. Development of embryo and fetus
2) Fetal hemoglobin
Fetal hemoglobin: early pregnancy
Adult hemoglobin: 32nd week
Term: fetal type Hb 25%
3) White cells
Leukocytes: 8 week
Lymphocytes (antibody production): 12
week, thymus and spleen
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14. Development of embryo and fetus
C. Gastrointestinal tract
1) drink amniotic fluid: 4th month
2) no proteolytic activity
3) enzymatic deficiencies in liver:
bilirubin is not easy to be clear.
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15. Development of embryo and fetus
D. Kidney
Its function begins at 11-14th week
E. Endocrinology
1) Fetal thyroid: the first endocrine
gland (6th week), synthesize
thyroxine at 12th week
2) Fetal adrenal cortex: widen (20th
week), a fetal zone. synthesize
steroid hormones ( liver placenta
mater)
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16. Placenta development
Early nutrition of the embryo
10th week
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17. Placenta - oxygen transport
• Similarities betwen placenta
and lungs
• Oxygen transport - simple
difusion
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18. Placenta
• Structure
1. Primary villus
syncytiotrophoblast
cytotrophoblast
1. Secondary villus
2. third class vilus
fetal capillary enter the stroma
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20. Placenta
Function
1.metabolism
1)Exchange of O2 and CO2
2)Exchange of nutritive factors and
waste
1.Defensive
Limited. IgG, virus, drug
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21. Placenta
Endocrine
1)Human chorionic gonadotrophic
2)Human placental lactogen
1)Oxytocinase
2)Cytokines and Growth Factors
1.Immunity tolerance
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22. Fetal membranes
Structure
chorion and amnion
Amnion
A double-layered translucent
membrane
Become distended with fluid
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23. Umbilical Cord
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24. Amniotic fluid
Source
1.exudation of fetal membranes
(early pregnancy)
2.Fetal urine
3.Fetal lung
4.Exudation of amnion and fetal
skin
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25. Cont
• Absord
1. Fetal membrane
2. Umbilical cord
3. Fetal skin
4. Fetal drinking
• Feature
1000-1500ml at 36th-38th week
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26. cont
Function
1.Protect fetal
move freely, warm
1.Protect mater
prevent infection
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27. Fetal physiology -
circulation
Fetal heart rate (FHR) – beating at 5 weeks –
100 beats/min
8 weeks – 160 beats/min
15 weeks – 150 beats/min
Birth – 130 beats/min
Bradycardia – slow pulse rate – very
dangerous to fetus
Blood flow – 40% to head/upperbody
30% to placenta
30% to lower body
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28. Fetal circulation
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29. Fetal Physiology - Respiration
Gross breathing movements at 11 weeks Rapid
and irregular – associated with REM
(rapid eye movements)
Isolated slow movements – gasps
Function of fetal breathing:
Stimulates growth of the lungs
Conditioning of muscles
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30. The First Trimester
Lasts from conception to the twelfth week of pregnancy
3periods during the first trimester:
– The Germinal Period
• Fertilized egg travels and implants in wall of uterus
• Implantation occurs 10-14 days after conception
– The Period of the Embryo
• Lasts from third through 8th week of pregnancy
• Major organs and anatomical structures begin to form
– The Period of the Fetus
• Lasts from ninth week of pregnancy until birth
• All major organs continu
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31. The Second Trimester
week 13-29
Fetus assumes distinct human appearance
• The nails harden and skin thickens, as well
as the eye lashes, eye brows, and scalp hair
appear during fifth and sixth months
• Fetus’s visual and auditory senses are
functional
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32. The Third Trimester
week 29to 40
All organ systems mature rapidly
• Fetus prepares for birth
• Fetus reaches ‘age of viability’, the point at which the
fetus can survive outside of the uterus
• Fetus shows better-organized gross motor activity, and
sleepiness/ waking activity
• Towards end of ninth month, fetus is positioned head-
down with limbs curled up in ‘fetal position’
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33. Physiologic changes in pregnant woman
• Genital organs
1. Uterus
1) capacity: 5ml-5000ml.weight: 50g-
1000g
2) Hypertrophy of muscle cells
3) Endometrium→ decidua: basal
decidua, capsular decidua, true
decidua
4) Contraction: Braxton Hicks
5) Isthmus uteri: 1cm→ 7-10cm
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34. Physiologic changes in pregnant woman
1) Cervix: colored
2) Ovary: placenta replaces ovary (10th
week)
3) Vagina: dilated and soft, pH↓ (anti-
bacteri bacteria)
4) Ligaments: relaxed
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35. Changes in the shape of the
uterus
• Isthmus elongates during the 1st
10 weeks like a stalk
• From 7mm to 2.5cms at 10 weeks
• Later becomes the lower
segment with the globular uterus
sitting on top
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36. Sep 18, 2012 36

37. BLOOD SUPPLY TO UTERUS
• Blood supply pre pregnancy =
10mls/min
• At 40weeks 800 – 900mls/min
• 20% of cardiac output goes to
uterus
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38. 8th week
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39. 12th week
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40. 16th week
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41. 20th week
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42. 24th week
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43. 30th week
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44. 36th week
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45. Sep 18, 2012 45

46. Physiologic changes in pregnant woman
The urinary system
1.Kidney
1)Renal plasma flow (RPF):↑ 35%
2)Glomerular filtration rate (GFR):↑ 50%
1.Ureter
Dilated (↑ )
1.Bladder
Frequent micturation
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47. Physiologic changes in pregnant woman
Cardiovascular system
1.Heart:
move upward, hypertrophy of
cardiac muscle
1.Cardiac Output
increase by 30%, reach to peak at
32nd –34th week
1.Blood pressure
early or mid pregnancy Bp↓. late
pregnancy Bp↑ .Supine hypotensive
syndrome
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48. Physiologic changes in pregnant woman
Hematology
1. Blood volume
1) Increase by 30%-45% at 32nd –34th
(peak)
2) Relatively diluted
1. Composition
1) Red cells
Hb:130→ 110g/L, HCT:38%→ 31%.
1) White cells: slightly increase
2) Coagulating power of blood: ↑
Sep 18, 2012 3) Albumin: ↓, 35 g/L 48

49. Hematologic changes
•plasma volume increases (50%)
•erythropoesis (RBC) increases (25%)
• decreased Hb, hematocrite
• Iron requirements increases significantly
• Iron suplements needed
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50. Physiologic changes in pregnant woman
The Respiratory system
1. R rate: slightly ↑
2. vital capacity: no change
3. Tidal volume: ↑ 40%
4. Functional residual capacity:↓
5. O2 consumption: ↑ 20%
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51. Physiologic changes in pregnant woman
• Gastrointestinal system
1) Gastric emptying time is
prolonged→ nausea.
2) The motility of large bowel is
diminished → constipation
3) Liver function: unchanged
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52. Increases in body weight
The average weight gained by the body
during pregnancy in about 12 kg the
approximate weight of various structures
which adds to the weigth gain
fetus : 3.5kg
Amniotic fluid : 2.0 kg
Placenta : 1.5 kg
Increases in matt. 5.0 kg
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53. Hormonal changes
Placenta mother aldosterone hypertension
CRH ACTH cortisol edema
insulin resistance
HCG hyperthyroidism
HC thyrotropin
gestational
diabetes
↑Calcium Hyperparathyroidism
demands
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54. CHANGES ARE DUE TO
• ALTERATIONS IN
• HORMONAL PRODUCTION
• CIRCULATION
• METABOLISM
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55. HORMONES
OESTROGEN
• Produced in corpus luteum
• Produced by placenta after 12 weeks
• Responsible for growth particularly of
uterus and breasts
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56. progesterone
• Produced in corpus luteum and then the
placenta
• Relaxes smooth muscle
• Inhibits uterine contractions until uterus is
prepared for labour
• Regulates storage of body fat
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57. Human chorionic gonadotrophic
• Secreted from trophoblast of the
developing embryo
• Maintains corpus luteum until
placenta takes over
• Used in tests to confirm pregnancy
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58. Human placental lactogen
• Alters maternal metabolism
• Diverts glucose to fetus
• Mobilises free fatty acids from
maternal stores
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59. RELAXIN
• Released by corpus luteum then
the Placenta
• Softens pelvic ligaments
• Reduces myometrial tone
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60. Changes in the reproductive system:
Uterus
• endometrium ………….decidua
• becomes more vascular and thicker due to
oestrogen and progesterone
• decidua provides glycogen rich enviroment
to nourish fetus until trophoblastic cells
develop into placenta
• decidual cells produce prolactin and relaxin
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61. MYOMETRIUM
• Smooth muscle fibres embedded
in a matrix of connective tissue
• Grow 15 – 20 times normal size
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62. PERIMETRIUM
• Stretches with uterus upwards and
outwards
• Can cause discomfort
• Spasm of broad ligament specially on
right side due to right uterine obliquity
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63. changes in size
uterus grows to 30x23x20 at term
weight increases to 900gms
hypertrophy.. Oestrogen causes cells
to increase until 20 weeks gestation
Hyperplasia:- number of cells increase
under the influence of oestrogen
.
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64. After 20 weeks gestation
• Uterine muscle tissue stretches
to allow fetus to grow
• Progesterone relaxes the smooth
muscles enabling it to stretch
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65. Changes in the cervix
• Length remains the same
• Increase in width
• Softening after third month due to
oestrogen
• Increased vascularity
• Increased cervical mucosa
• Increased glandular function
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66. BY 12 WEEKS
• Uterus is upright and leans
slightly to the right
• No longer a pelvic organ
• Uterus may be palpable above
the pubic bone
• Fetus now occupies most of the
uterine cavity
• Placenta now developed
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67. BLOOD CHANGES
• Increase in oestrogen:
new blood vessels formed
growth of existing ones
• Therefore an increase in blood
volume.
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68. • Blood volume: from 5 litres to 7.5
total volume up by 40-50%
• Red cell mass: rises constantly
throughout pregnancy Up by 20% by end
of pregnancy
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69. PLASMA VOLUME
Increases from 10th week of pregnancy
variable related to parity, fetal weight
and number
Reaches maximum level approx 50%
above non-pregnant levels at 32-34
weeks then maintained
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70. Month nine
• Lightening – Fetus descends to pelvic cavity
• Cervix – Dilation, Effacement (softening,
• thinning)
• False Labor – Contractions initiate then
• diminish
• Labor:
• Cervical effacement – dilation to 10 cm
• Bloody Show – mucus plug of the cervix – blood-colored
• Breaking Water Bag – rupturing of the amnion
• Contractions – shorter intervals, longer, stronger
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71. Uterine Contraction
• Uterine musculature becomes progressively more excitable
• Estrogen/progesterone ratio changes increases excitability
• Progesterone inhibits contraction
• Estrogen increases gap junctional communication between
• smooth muscle cells  increases contractility
• Oxytocin (maternal posterior pituitary gland) increases
excitability
• Mechanically stretching uterine smooth muscle increases
• contractility
• Cervical stretching elicits uterine contractions
• Fetal effects –glucocorticoids  placenta inhibits
progesterone
• Fetal oxytocin is also produced
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72. Labor and Parturition
Parturition: Process by which the
•baby is born
•Labor: Strong uterine contractions,
•Cervix stretching, Forcing the
•fetus through the birth canal
•Rhythmic strong uterine contractions expel the fetus
•Positive-Feedback regulation of labor
•Contractions push baby  stretch cervix
•Stretched cervix Stronger uterine contraction
•Cycles until parturition is complete
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73. contd
• Contractions: 30 minutes  1-3 minutes
• Contractions strongest at top of uterus – forcing baby
• toward cervix (25 lbs/contraction)
• Continuous contractions (tetanus) can stop blood flow and
• lead to death of the baby
• First stage of labor: cervical dilation (8-24 hours)
• Second stage of labor: passage through birth canal
(few minutes to half hour)
• Third stage of labor: expulsion of the placenta
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74. After Birth
• 10-45 minutes after parturition the placenta is
• Delivered
Separation and Expulsion
Separation - Uterine cavity reduces in size 
• shearing the placenta from the uterine wall
Limited bleeding – controlled by local production
• of vasoconstrictors (prostaglandins)
• Expulsion is by uterine contraction
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75. Conditions During
Pregnancy
• Constipation
– Affects half of pregnant women
– Causes:
• increase in progesterone
• the colon absorbing more water
• worse in first 13-14 weeks
– Treatment:
• Drink plenty of fluids
• Eat high fiber foods
• Take fiber supplements – psylium husks,
Metamucil, Ex-Lax
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76. Cardiovascular change
• Displaced to left and upward
• Apex is move laterally
• Apparent cardiomegarty on chest x- ray
• Increase of left ventricular end diastolic
dimension
• increase of left ventricular wall mass c/w
mild hypertrophy increase in preload
increase
capacitance of the systemic pulmonary
vascular resistance pregnant rise to cvp
or wedge pressure
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77. Nausea and Vomiting during
Pregnancy (NVP)
(Morning Sickness)
• Peaks during the first Trimester
• Positive correlation with birth weight
• Negative correlation with spontaneous
abortions
• Nausea – 50-70% of pregnant women
• Vomiting – 40-50% of pregnant women
• Less than 2% is solely in the morning
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78. Breast
Development
Pregnancy
Hormone-Dependent Growth
Estrogen
Growth Hormone
Prolactin
Adrenal glucocorticoid
Insulin
• Growth and branching of the ductal system
Fat Deposition
• Progesterone: Final stages – synergistic with other
hormones – growthof lobules, budding of alveoli,
secretory characteristics, but not secretion
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79. Lactation
Prolactin:
Promotes milk secretion Anterior
pituitary
Hypothalamus (inhibition)Steady rise
week 5 – birth stimulates
colostrum – low volume, no fat
birth – sudden drop in Estrogen and
Progesterone1-7 days prolactin
induces high milk production
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80. Cont
Other hormones are required:
growth hormone, cortisol, parathyroid
hormone
Prolactin production is
stimulated by signals from the nipple to
hypothalamus(repression of prolactin-
inhibiting hormone)  Anterior Pituitary
 10-20x surge of prolactin
Nursing can continue for years
Once nursing stops - milk production
declines within a week
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81. Milk Letdow
Milk secreted into the alveoli of the breast, but
must be ejected to the ductal system.
Oxytocin (posterior pituitary) stimulates this reflex
Oxytocin production controlled by hypothalamus
(direct innervation of the posterior pituitary
gland)
Oxytocin induces contraction of myoepithelial cells
around the alveoli
Oxytocin induced by suckling and also crying
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82. BREAST FEEDING FEEDBACK
LOOP
– suckling of baby stimulates nerves in the
areola of breast
– this stimulates the pituitary to release
prolactin and oxytocin
– the prolactin initiates milk production and
moves milk into ducts
– oxytocin causes weak contractions in the
breast to move the milk
– oxytocin also causes weak contractions in
the uterus to return the uterus to its normal
size and shape, thus breast-feeding mothers
regain uterine muscle control quicker
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83. • Hear baby cry  release oxytocin  start to
move milk "milk let down“
• Stress à lowers milk release  lots of milk 
no release  increased pressure pain (thus
it is important to be relaxed and in a quiet area
to feed)
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84. SFCC: Figure 14.14
84
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85. During Lactation Don’t:
• Don’t drink alcohol
• Don’t take medications unless OK by
Medical Provider
• Don’t take illegal drugs
• Don’t smoke
• Don’t get into environmental
contaminants
• Don’t have caffeine
85
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86. Yoga for pregnancy
• Help with breathing and relaxation
• Promote feelings of well-being
• Energizing
• Stress relief
• Improve posture
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87. Yoga for pregnancy
• Control of excess weight gain
• Appearance Improved sleep
• Decreased back pain
• Decreased water retention
• decrease in complications during
labour
• Shortened labour
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88. Swimming
• Uses large muscle groups of the
legs and arms
• No strain on ligaments
• Feeling of weightlessness
• Improved circulation
• Water Temp 18-25 °C
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89. Disadvantages of Not Yoga
practice
• Studies have shown that women
who yoga practice do not
experience an increase in:
– Premature Rupture of Membranes
(PROM)
• When the membranes that hold the
amniotic fluid break too early.
– Congenital Abnormalities
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90. Exercises to Avoid During
Pregnancy
• Ball sports
• Contact sports: ultimate fighting, wrestling, football
• Sports that involve bouncing, leaping, a sudden
change of direction (increased joint laxity from
hormones make joints susceptible to sprains)
• Exercises that put you at risk for falls: rollerblading,
horseback ridding, skiing
• After 1st trimester avoid exercise in the supine
position
• Lying in the prone position
• Lifting heavy free weights
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91. Contraindications to Exercise
• Premature rupture of membranes
• Preterm labor during the prior or current pregnancy
• Persistent 2nd or 3rd trimester bleeding
• conditions such as:
– Cardiac disease, constrictive lung disease
– Chronic hypertension
– Severe anemia
– Chronic bronchitis
– Extreme obesity
– Extreme underweight
– History of an extremely sedentary lifestyle
– Orthopedic limitations
– Heavy smoker
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92. And Finally…
THANK YOU
Sep 18, 2012 92