Obstetrics - Physiology of Pregnancy Flashcards
Weight gain during pregnancy
- Causes
- Normal parameters
Carbohydrate and lipid metabolism changes
- Cause
- Changes from normal
- Course
Physical changes of respiratory apparatus during pregnancy
- List changes
- Causes
Changes in ventilatory parameters and blood gas parameters during pregnancy
- List changes
- Causes
Changes in tissue oxygenation during pregnancy
- List changes
- Causes
Cardiovascular changes during pregnancy
Common CVS exam findings
Pregnancy changes mimics S/S of heart failure
- SOB - elevation of diaphragm, adjustments in lung volumes and RR
- Edema - ↑ total body Na and water, venous compression by gravid uterus
- Lightheadedness, syncope - ↓ venous return due to compression
- Palpitations - ↑CO in pregnancy
CVS findings:
- Sinus tachycardia
- JVP - height remains unchanged
- Peripheral pulses - ↑volume
- Atrial and ventricular ectopic beats
- Loud ± split S1, S3, ejection systolic murmur (flow murmur, from 2T onwards and disappears upon delivery)
Changes in cardiac and vascular parameters during pregnancy
- List changes
- Causes
Haematological changes during pregnancy
- Blood cell, clotting changes
- Plasma changes
Renal changes during pregnancy
- Anatomical changes
- Functional changes
Renal changes during pregnancy
- Electrolyte and glucose balance
Gastrointestinal changes during pregnancy
- Oral
- Gastric
- Bowel
- Liver
Reproductive organ changes during pregnancy
- Breast
- Uterus
Reproductive organ changes during pregnancy
- Cervix
- Vagina
Outline list of homrones produced by fetal-placenta unit
Pregnant uterus produces a wide variety of hormones!
○ Pregnancy-specific: hCG, human placental lactogen (hPL)
○ Hypothalamus: GnRH, CRH, TRH
○ Pituitary: prolactin, GH, ACTH
○ Sex hormones: estrogen, progesterone
○ Kidney: renin, angiotensin II
○ Liver: insulin-like growth factor I/II, 1,25-dihydroxycholecalciferol
○ Parathyroid: parathyroid hormone related peptide
○ Stomach: gastrin
hCG
- Source and course
- Changes during pregnancy
- Function
- Clinical use
Estrogen and progesterone
- Source and course
- Functions
CRH and ACTH
- Source and course
- Function
Pituitary hormones
- Changes during pregnancy
- Functions
↑prolactin - up to 15× normal, from anterior pituitary gland
- Stimulated - estrogen, suckling and sleep
- Inhibited - human placental lactogen (hPL) and dopamine
- Function - acts to ↑lactation (see above), relieve stress and regulate insulin secretion in post-natal period
↑oxytocin from posterior pituitary gland during labor and after delivery
- Action - myoepithelial contractions, relieve stress
Thyroid hormones
- Changes during pregnancy
Thyroid
- hCG mimics TSH action
○ hCG highest in 1st trimester → TSH level is suppressed with ↑fT4 and ↓response to TRH
○ Returns normal after that
- ↑ thyroxine-binding globulin* - therefore total T3/T4 never useful in pregnancy
○ Course - occurs from 2 week and plateau by 20 weeks
○ Consequence - leads to ↑T3 + T4 production
- ↑ iodine uptake in thyroid - due to ↑iodine loss secondary to ↑GFR
Skin changes during pregnancy
Hyperpigmentation (tend to regress after delivery) - usually at
- Pre-existing skin lesion, eg. moles, freckles and scars → may ↑ in size and numbers
- Normal pigmented skin areas, eg. areolae, nipples, axillae and periumbilical skin
- Along linea alba, i.e. linea nigra
- On the face, i.e. melasma
Striae gravidarum +/- pruritus of abdomen
↑Sebaceous gland activity
- Acne
- Montgomery tubercles
Hirsutism - therefore a larger proportion of hair enter telogen phase ~1-4mo after delivery
- present as massive hair shedding
