CVS , RS, Hem, Skin obstetrics and gynecology rotation

1. PHYSIOLOGICAL CHANGES
DURING PREGNANCY..
- Cardiovascular System (CVS)
- Respiratory System (RS)
- Hematological and Immune System
- Skin Changes
BALQEES MAJALI

2. CARDIOVASCULAR
SYSTEM

3. CVS
• Increase in level of oestradiol and prostaglandins (PGI2)
• Peripheral vasodilatation
• 25–30% fall in systemic vascular resistance
• Increase in cardiac output by around 40%
• This is achieved predominantly via an increase in stroke volume,
but also to a lesser extent, an increase in heart rate

4.  An increase in stroke volume is possible due to the
early increase in ventricular wall muscle mass and
end-diastolic volume (but not end-diastolic pressure)
seen in pregnancy.
 The heart is physiologically dilated and myocardial
contractility is increased. Although stroke volume
declines towards term, the increase in maternal heart
rate (10–20 bpm) is maintained, thus preserving the
increased cardiac output.
 Blood pressure decreases in the first and second
trimesters but increases to non-pregnant levels in the
third trimester

5. Supine Hypotensive Syndrome
By 20 weeks of gestation, the gravid uterus begins to cause mechanical
compression of inferior vena cava (IVC) and descending aorta in supine position
This leads to a decrease in venous return and CO resulting in maternal hypotension
and foetal compromise (acidaemia)
It is characterised by pallor, transient tachycardia followed by bradycardia,
sweating, nausea, hypotension and dizziness in supine position which get relieved
by turning lateral. In its severe form, it can lead to unconsciousness or sudden
maternal death.

6. * Pulmonary vascular resistance (PVR), like systemic
vascular resistance (SVR), decreases significantly in normal
pregnancy
• Although there is no increase in pulmonary capillary
wedge pressure (PCWP), serum colloid osmotic pressure
is reduced by 10–15%
• The colloid osmotic pressure/pulmonary capillary wedge
pressure gradient is reduced by about 30%, making
pregnant women particularly susceptible to pulmonary
oedema
• Pulmonary oedema will be precipitated if there is either
an increase in cardiac pre-load (such as infusion of fluids)
or increased pulmonary capillary permeability (such as in
pre-eclampsia) or both.

7. • further increases in cardiac output (15% in the
first stage and 50% in the second stage) Uterine
contractions lead to an auto-transfusion of 300–
500 ml of blood back into the circulation and the
sympathetic response to pain and anxiety further
elevate the heart rate and blood pressure. Cardiac
output is increased between contractions but
more so during contractions
During
Labor
• there is an immediate rise in cardiac output due to
relief of the inferior vena cava obstruction and
contraction of the uterus, which empties blood into
the systemic circulation. Cardiac output increases
by 60–80%, followed by a rapid decline to pre-labor
values within about one hour of delivery.Transfer of
fluid from the extravascular space increases venous
return and stroke volume further
Following
Delivery

8. Physical Examination

9. RESPIRATORY
SYSTEM

10. RS
There is a significant increase in oxygen demand
during normal pregnancy.This is due to a 15%
increase in the metabolic rate and a 20% increased
consumption of oxygen.
There is a 40–50% increase in minute ventilation,
mostly due to an increase in tidal volume, rather than
in the respiratory rate.This maternal hyperventilation
causes arterial pO2 to increase and arterial pCO2 to
fall, with a compensatory fall in serum bicarbonate to
18–22 mmol/l .
A mild fully compensated respiratory alkalosis is
therefore normal in pregnancy (arterial pH 7.44).

11. Reference ranges for respiratory function in pregnancy
Normal values
Investigations pregnant Non pregnant
pH 7.40–7.47 7.35–7.45
pCO2, mmHg (kPa) ≤ 30 (3.6–4.3) 35–40 (4.7–6.0)
pO2, mmHg (kPa) 100–104 (12.6–14.0) 90–100 (10.6–14.0)
Base excess No change +2 to –2
Bicarbonate (mmol/l) 18-22 20-28

12. Diaphragmatic elevation in late pregnancy results in
decreased functional residual capacity but diaphragmatic
excursion and therefore vital capacity remain unaltered.
Inspiratory reserve volume is reduced early in pregnancy,
as a result of increased tidal volume, but increases in the
third trimester, as a result of reduced functional residual
capacity.
Peak expiratory flow rate (PEFR) and forced expiratory
volume in one second (FEV1) are unaffected by
pregnancy.
Pregnancy may also be accompanied by a subjective
feeling of breathlessness without hypoxia.This is
physiological and is most common in the third trimester
but may start at any time during gestation. Classically, the
breathlessness is present at rest or while talking and may
paradoxically improve during mild activity.

15. HEMATOLOGICAL and
IMMUNE SYSTEM

16. Discrepancy in increase in plasma volume
(40–50%) and red cell mass (20%) results in
physiological anemia of pregnancy.
A lower haematocrit decreases the blood
viscosity and lowers the resistance to blood
flow in utero placental circulation
The leukocyte count gradually increases to
around 15,000/mm. Major contribution in
this increase is by polymorphonuclear cells,
which have impaired function.This explains
the increased severity of infections but this
apparently impaired immunity does not
make parturient prone to infections.
There is an increased production of platelets
but due to enhanced destruction and
haemodilution, rise in count does not occur.
In a minority, platelet count decreases
(90,000–100,000) which is physiological
(gestational thrombocytopaenia) and
resolves in the postpartum period

17. Hypercoagulability
The coagulation and fibrinolytic pathways are altered with an
increased risk of thromboembolism during pregnancy (10 times)
and postpartum (25 times)
• The concentration of all clotting factors increases except factor
II,V, XI and XIII.
• There is a reduction in prothrombin time and activated partial
thromboplastin time by 20%
• Elevated levels of fibrin degradation products and plasminogen
The hypercoagulable state is maintained up to 5–7 days postpartum
with increased risk of thrombotic complications and reverts to
baseline by 2 weeks postpartum.

18. SKIN CHANGES

19. Physiological changes
• Pigmentary changes
• Hair and nail changes
• Connective tissue changes
• Vascular changes
• Glandular changes
Specific dermatoses of pregnancy
- Linear IgM disease of pregnancy
- Papular dermatitis of pregnancy
- Pustular psoriasis of pregnancy
- Autoimmune progesterone dermatitis of pregnancy
Dermatological conditions modified by pregnancy
- Allergic contact dermatitis
- Psoriasis (2/3 improves)
- Systemic sclerosis
- Systemic lupus erythematosus
- Atopic dermatitis
- Acrodermatitis enteropathica

20. Pigmentation
It has now been proved that estrogen increased
the output of melanin by the melanocytes and
also that the effect of estrogen is augmented by
progesterone
The placenta is rich in bioactive sphingolipids,
which induce melanogenesis by upregulating
various melanogenic enzymes—tyrosinase and
tyrosinase-related proteins 1 and 2.

21. There is usually a mild generalized pigmentation, most
marked in areas that have already slightly darker than
the surrounding skin like the nipples, areola,
periumbilical skin, neck, upper back, and midline of the
abdomen
Darkening of the skin adjoining the areola produces
secondary areola, linea alba turns dark to become linea
nigra especially in dark-complexioned individuals
Melasma or chloasma gravidarum occurs in about 45–75
% of pregnant women.

22. Management of the pigmentary disorders
during pregnancy involves mainly reassurance
and asking the patient to avoid sun exposure, as
the hormonal cause of the pigmentation
persists throughout the pregnancy and the
mainstay therapy of the hyperpigmentation is
contraindicated during pregnancy.

23. Hair
 Hirsutism and accompanying acne can be found in
many pregnant women especially toward the term.
 Scalp hair becomes fuller during pregnancy which is
due to increase in the mean diameter of the scalp hair.
 After the delivery : hair fall starting from 70 to 80 days
postpartum. Although complete hair regrowth usually
occurs, the hair may not be as abundant as it was
before. Rarely a male-pattern baldness and
hypotrichosis are seen especially in women with a
tendency toward androgenetic alopecia.

25. Physiological Connective Tissue Changes
During Pregnancy
striae
• Striae distensae appear in 90 % of pregnant women from the sixth to
seventh month as purple streaks
• It occurs as a result of combination of distension and genetic and
adrenocortical activities, which leads to intradermal tears of collagen
• Preventive measures by different topical therapies are controversial .
Optional postpartum treatments include tretinoin, excimer laser, and
surgical excision.
• Molluscum fibrosum gravidarum and Acrochordons are identical to
skin tags.They occur from the fourth to sixth month of pregnancy and
usually disappear after parturition

26. Physiologic Vascular Changes During Pregnancy
Vascular spiders or spider nevi are seen mostly in areas of
skin drained by the superior vena cava, the neck, throat,
face (particularly around the eyes), upper chest, arms, and
hands.They appear as small, flat, or slightly raised lesions
with a central, faintly pulsating, red punctum associated
with small, radiating, telangiectatic vessels, and
surrounding erythema.
.
Palmar erythema, hemangiomas, cutis marmorata,
purpura, petechia, edema, carpal tunnel syndrome,
varicosities, hemorrhoids, pregnancy gingivitis, and
granuloma gravidarum or pregnancy epulis are the other
vascular changes seen in pregnancy

27.  PhysiologicGlandular Changes During Pregnancy:
Eccrine gland activity generally increases during
pregnancy, often leading to hyperhidrosis, miliaria, and
dyshidrotic eczema.Apocrine gland activity usually
decreases during pregnancy. Sebaceous gland function
increases
• Key Points:
- Reassurance and counseling of the patient needs to be
done.
- Patient cautioned against using any over-the-counter
medications for pigmentation and other changes.
- No need for any invasive investigations or procedures
at this stage.

28. THANK YOU