Physiological Changes in Pregnancy

Question 1

Anterior pituitary produces more? (3)

Answer 1

ACTH
Prolactin
Melanocyte stimulating hormone

Question 2

High ACTH results in?

Answer 2

Rise in corticosteroid hormones such as cortisol and aldosterone

Question 3

What conditions tend to get better during pregnancy due to increased ACTH levels?

Answer 3

Autoimmune conditions

Question 4

What conditions tend to get worse during pregnancy due to increased ACTH levels?

Answer 4

Diabetes

Question 5

What do the high levels of prolactin do?

Answer 5

Suppress FSH and LH

Question 6

Increased melanocyte stimulating hormone results in?

Answer 6

Increased pigmentation during pregnancy (e.g. linea nigra, melasma)

Question 7

What happens to thyroid hormones?

Answer 7

TSH stays normal

but T3 and T4 levels rise

Question 8

bHCG levels?

Answer 8

Rise, roughly double every 48 hours until week 8-12 then fall gradually

Question 9

Progesterone levels?

Answer 9

Rise throughout pregnancy, prevent contractions and supress mothers reaction to foetal antigens

Question 10

Oestrogen levels?

Answer 10

Rise throughout pregnancy

Question 11

Changes in uterus?

Answer 11

Increases in size

Hypertrophy of myometrium and blood vessels

Question 12

Changes in cervix?

Answer 12

Cervical ectropion and increased cervical discharge may occur due to increased oestrogen

Question 13

Changes in vagina?

Answer 13

Hypertrophy of vagina muscles

Increased discharge preparing vagina for delivery but also increases chance of infection

Question 14

Prior to delivery, what breaks down collagen in the cervix to soften it?

Answer 14

Prostaglandins

Question 15

Cardiovascular changes?

Answer 15

Increased blood volume
Increased plasma volume
Increased cardiac output

Decreased peripheral vascular resistance
Decreased blood pressure in early and middle term
Varicose veins can occur
Peripheral vasodilation can cause flushing and hot sweats

Question 16

Respiratory changes?

Answer 16

In later pregnancy:
Tidal volume increases
Respiratory rate increases

Question 17

Renal changes?

Answer 17

Increased:

• blood flow to kidneys
• GFR (about 50%)
• aldosterone leads to increased salt and water reabsorption
• protein excretion

Uterus and collecting system dilate leading to a physiological hydronephrosis

Question 18

Haematological and Biochemical changes?

Answer 18

Increased:

• red cell production
• White cell and platelet count
• Clotting factors
• ESR and D-dimer
• ALP levels up to 4x due to placental secretion

Decreased:

• concentration of red cells in increased plasma levels
• albumin

Calcium levels stay the same

Question 19

Skin changes?

Answer 19

Increased pigmentation
Striae gravidarum
Pruritus (could indicate obstetric cholestasis)
Spider naevi
Palmar erythema
Hair loss postpartum is normal, usually improves within 6 months