Physiological Changes in Pregnancy Flashcards
Which hormones does the anterior pituitary increase during pregnancy
ACTH, prolactin and melanocyte stimulating hormone
What is the effect of increased levels of ACTH in pregnancy
Causes a rise in steroid hormones such as cortisol and aldosterone
What is the effect of increased levels of prolactin in pregnancy
It suppresses LH and FSH
What are the effects of increased levels of melanocyte stimulating hormone in pregnancy
Increased pigmentation in skin leading to linea nigra and melasma
What happens to thyroid hormones during pregnancy
TSH remains normal
T3 and T4 rise
What happens to hCG levels during pregnancy
Roughly double every 48 hours until 8-12 weeks, then plateau, and then gradually start to fall
Why do levels of progestone rise throughout pregnancy
Acts to maintain pregnancy, prevent contractions and suppress mothers immune reaction to fetal antigens.
What causes the levels of oestrogen to rise during pregnancy
Placenta
What causes the levels of progesterone to rise during pregnancy
Corpus luteum and then the placenta
What changes occur to the uterus, cervix and vagina during pregnancy
Hypertrophy of myometrium and blood vessels, hypertrophy of vaginal muscles and increased vaginal discharge
Cardiovascular changes in pregnancy
Increased blood volume, plasma volume, cardiac output.
Decreased peripheral resistance and blood pressure.
Varicose veins due to vasodilation and obstruction of IVC by uterus, which also causes flushing and hot sweats
Respiratory changes in pregnancy
Tidal volume and respiratory rate increase in later pregnancy to meet increased oxygen demands
Renal changes in pregnancy
Increased blood flow to kidney, GFR, aldosterone (salt and water retention), protein excretion.
Dilatation of ureters and collecting system leading to physiological hydronephrosis
Haematological changes in pregnancy
Anaemia
Hyper-coagulable state
Increased and decreased molecules on blood results.
Which haematological agents increase during pregnancy
WBCs, RBCs, plasma volume, clotting factors, ESR, D-dimer, ALP
Which haematological agents decrease during pregnancy
Platelet count, albumin (loss of protein in kidneys)
Why do calcium levels remain stable in pregnancy
Calcium requirements increase but so does the gut absorption
Why do calcium levels remain stable in pregnancy
Calcium requirements increase but so does the gut absorption
Why does anaemia occur in pregnancy
There is an increase in RBC production but also plasma more so, which reduces the concentration. Requirement of more iron, folate and B12 from increased RBC production.
Why do mothers enter a hypercoagulable state in pregnancy
Fibrinogen, factor VII, VIII and X increase during pregnancy -> increased risk of VTE
Skin and hair changes which occur in pregnancy
Increased skin pigmentation, striae gravidarum, pruritis, spider naevi, palmar erythema, hair loss post partum
GI changes in pregnancy
Early pregnancy vomiting mediated by hCG. Increased gastric emptying and gastro-oesophageal sphincter tone leading to acid reflux. Decreased colonic motility (constipation). Biliary stasis due to progesterone. Haemorrhoids
Metabolic changes in pregnancy
Increased protein metabolism and deposition so increase in weight. Increased carbohydrate metabolism and insulin resistance.
MSK changes in pregnancy
Relaxation of sacroiliac joints and symphysis pubis, facilitating vaginal delivery but may lead to discomfort. Soft tissue remodelling and joint changes. MSK pain. Lordosis.
