Maternal Physiology in Pregnancy

Question 1

Explain the maternal physiological adaptations to pregnancy

Answer 1

CVS = increased plasma vol, CO, SV, HR. Increase in clotting factors, compression of IVC

Kidneys = increase renal blood flow/GFR

Liver = changes in CYP450

Lungs = increase tidal volume and minute ventilation, elevated diaphragm

Stomach/intestines = nausea/vomiting, delayed gastric emptying, prolonged SI transit time, GI reflux

Endocrine = hPL (makes female more insulin resistant), increased thyroid activity

Uterus = size increase

Vagina = hyperplasia of lining, more secretions

Breasts = increased size, thin watery secretions

Question 2

Explain the aetiology of the major complications of pregnancy

Answer 2

Obstetric cholestasis = intense itching, raises LFT and bile salts. Associated with still birth = increased bile salts crosses placenta, effects foetal heart = arrhythmias

Pre-eclampsia = trophoblast doesn’t invade endometrium correctly, toxins released into maternal circulation, vasoconstriction (raised BP), leaky capillaries (proteinuria in kidneys), vessel damage (low platelets, DIC)

Gestational DM = hPL causes insulin resistance

Question 3

Describe the hallmark clinical features of pre-eclampsia

Answer 3

New onset raised BP

New onset raised proteinuria

<20 weeks = as placenta is still developing

Seizures

Question 4

Outline gestational diabetes

Answer 4

hPL = insulin resistance

More common in asians

Associated with family history of DM

More common in women with poly-cystic ovarian syndrome

= foetal macrosomia, stillbirth, neonatal hypoglycaemia

Question 5

Outline anaemia in pregnancy

Answer 5

plasma volume increases, RBC mass stays the same = dilutes RBCs

Question 6

Outline thrombosis in pregnancy

Answer 6

Increased risk due to a rise in clotting factors

Give thromboprophylaxis during pregnancy and postnatal (higher dose for higher weight)