Physiological changes during pregnancy

Question 1

What are the skin changes that occur during pregnancy?

Answer 1

1- cholasma or melasma (on face)
2- hyperpigmentation or areola & genital skin
3- linea alba to nigra
4- stria gravidarum after half of pregnancy
5- palmar erythema (due to increased estrogen)
6- vascular spiders

Question 2

What are the cardiovascular changes that occur in pregnancy?

Answer 2

1- increased cardiac output (50%) & heartbeat (10 - 15 beats) & plasma volume (50%)
2- left axis deviation -> due to displacement of heart upward & to the left
3- worsening of pre-existing or masked heart disease
4- systemic & pulmonary vascular resistance decreases
5- loud third heart sound
6- ejection systolic murmur (increased flow through aortic valve)
7- supine hypotension

Question 3

What is the cause of supine hypotension & how is it relieved?

Answer 3

the gravid uterus blocks the inferior vena cava -> reduces venonus return -> hypotension

• relieve by tilting patient to the left side

Question 4

What are the changes that will occur in the respiratory system?

Answer 4

1- decreased functional residual capacity 20-30%
2- respiratory alkalosis due to hyperventilation
3- decrease in bicarb as compensation
4- increased tidal volume & minute ventilation 40%
5- oxygen consumption increased by 20%
6- dyspnea -> due to increased tidal volume

Question 5

What are the GI changes that occur?

Answer 5

1- reduced LES tone -> heartburn
2- hemorrhoids -> secondary to constipation
3- increase in gallbladder volume due to stasis -> may lead to gallstones
4- ALP doubles
5- ALT GGT decreases

Question 6

What are the causes of increased blood volume by 40-45%?

Answer 6

• meet the needs of the enlarged uterus
• deliver nutrients rapidly to placenta & fetus
• protect the mother from effects of parturition blood loss

Question 7

What are the hematological changes that occur?

Answer 7

1- dilutional anemia -> increase in plasma volume is more than erythrocyte mass
2- leucocytes increase up to 15 000 by term
3- increased concentration of all coagulation factors except XI & XIII
4- platelet count declines during pregnancy but return to normal 4-12 weeks postpartum

Question 8

What are the renal changes that occur?

Answer 8

1- increased GFR by 25% & renal plasma flow by 80% -> frequency & nocturia
2- glycosuria
3- ureteral dilation, hydroureter & hydronephrosis
4- decreased blood urea nitrogen & creatinine
5- proteinuria (abnormal >300mg/day)

Question 9

What are the reproductive system changes?

Answer 9

1- uterine size increases from 70 to 1100 gm
2- hypertrophy of muscle
3- size increases by content of conception by week 12
4- blood flow increases to uterus by 500-750ml by 36 weeks

Question 10

What is the average weight gain for a pregnant lady?

Answer 10

12.5 kg or 27.5 pounds

Question 11

What changes will occur in the endocrine system?

Answer 11

1- thyromegaly
2- increased iodine requirement
3- Thyroid binding globulin increases -> increased total T4 & T3 but free are unchanged
4- increased ACTH & free cortisol