Maternal Biological Adaptation to Pregnancy - Maymon

Question 1

What are physical changes in the uterus during pregnancy?

To the vagina?

Answer 1

Growth from 40-70g to 1200g
Hypertrophy (cells themselves grow in size) and hyperplasia
Perfusion up to 500-700cc/min

Increased Vascularity
Bluish purple color (mucosa)- Shadwick’s sign
Thickening of Mucosa
Hypertrophy of Smooth muscle

Increased vaginal secretion
pH 3.8-4.0
Preterm labor: increased pH

Question 2

What are cardiovascular, respiratory, hemodynamic and hematological changes in pregnancy?

Answer 2

Rises progressively (40% - 50%)
6-8 weeks 32 weeks
Correlated with fetal size and increased in multiple pregnancies

20% - 30% (decreased Hct)
Back to normal 3 weeks postpartum

Myocardial hypertrophy
Increased muscle mass ventricular wall
Myocardial contractility
Decreased Vascular resistance

30-50% (12-32 weeks) Increase in cardiac output
Stroke volume increases
Aortocaval Compression by uterus causing cardiac output decrease when supine

Blood pressure Decrease (depend on maternal position)
Increases towards 40 weeks
If > 90 systolic then consider hypertension!

Increased hepatic production of fibrinogen
Increased fibrin (placental deposition)
Depression in fibrinolysis
Hypercoagulable state
Decrease plasma fibrinolytic activity
Placental production of fibrinolytic inhibitors
Successful coagulation at delivery

Diaphragm up 4 cm
Transverse thoracal diameter increases by 2 cm
Thoracic circumference increases by 6 cm
Physiological respiratory alkylosis

Question 3

What are physical changes of the internal organs (bladder, kidneys, pancreas)?

Answer 3

Increase renal size 1.5 cm
Increase in vascular volume
Dilatation of renal pelvis
Ureters displaced laterally by the uterus
Hydroureter, hydronephrosis
Progesterone reduces peristalsis of the ureters
UTIs (asymptomatic bactiuria) can cause premature delivery without pain
Increase in plasma flow by 50%
Increase in GFR
Creatinine clearance 120-160 ml/min
Plasma urea, uric acid and creatinine decreases (if an increase, even within normal values, need to examine)
Sodium reabsorption increases
Plasma osmolarity decreases (more volume)

Glucosuria, increased albumin excretion (decreased concentration in the blood)

Hyperplasia of Beta Cells
Increase Insulin Secretion
Increase sensitivity to lower dose of glucose
Exaggerated plasma insulin response to given oral glucose load
Fasting glucose decreases 20%
Fasting hypoglycemia(increased insulin and glucose usage)- mother should eat every few hours
If mother is hypoglycemic can increase fetal disposition to diabetes and heart disease later in life
Glucose storage mobilization/Hepatic glycogenolysis
Increase insulin resistance: (Human Placental Lactogen, Prolactin-100x higher, Cortisol)
Post prandial glucose are elevated

Question 4

What are changes in skin and the musculoskeletal system during pregnancy?

Answer 4

Increased pigmentation (90% of women)
Melansma gravidarum (mask of pregnancy)
Areola of breast darkens
linea alba becomes linea negra
axilla darkens
genital skin darkens
MSH (melanocyte stimulating hormone)
Vascular dilatation
Angioma (spider angiomata)- reversible
Redness of palms and palmar erythema
Striae gravidarum(estrogen, not reversible): linear (not longitudinal like in Cushings) tears in dermal skin of Abdomen, Thighs and Buttocks)
Decrease in body hair growth

Sacroiliac joint ligaments and pubic symphysis are softened
Separation of joints
Widening of symphysis pubis 3-4 mm (can make it difficult to walk)
Progressive lordosis of spine (for volume of uterus)
Carpal tunnel syndrome (edema in third trimester, can cause fingers to be stiff, reversible- with HTN can be preeclampsia)