Cardiovascular

• SV up 30%, HR up 15% & cardiac output up 40%

Blood pressure

• Increase in CO and plasma volume
• Decrease in MAP - At around the middle of pregnancy (Due to the placenta causing an overall reduction in the systemic vascular resistance)
• Decrease in BP (more so Diastolic due to reduced SVR) - reduced SVR is due to development of new vascular beds and vasodilation

Heart

• Increased blood flow - Can cause a (normal) end diastolic flow murmur
• IF the patient has a pre-existing valvular disease they may not be able to increase CO, may lead to heart failure
• enlarged uterus may interfere with venous return which can lead to ankle oedema, supine hypotension and varicose veins

Vascular

• Progesterone results in decreased peripheral vascular resistance which leads to venous pooling of blood therefore increasing hydrostatic pressure above oncotic and as a result peripheral oedema occurs.

Blood

• ⬆️ Blood volume by 30% - Helps fill expanded vascular spaces and maintain BP (at birth mother has extra 1-2L blood)
• ⬆️ Plasma volume - RAAS activity
• Haemodilution
• Most common cause of anaemia in pregnancy - Iron deficiency anaemia
• ESR and WCC rise