Physiology of pregnancy Flashcards

Question

BP = CO x TPR the cardiac output increased 40-50% in pregnancy due to ++SV (CO=SV xHR). therefore, What happens to BP in pregnancy?

Answer 1

TRICK! BP decreases in pregnancy... it normalises towards the end of pregnancy because BP = CO x TPR and TPR DECREASES =\> progesterone is a smooth muscle relaxant --\> vasodilation increased flow to uterus, placenta, muscle, kidney, skin (neoangiogenisis) check BP at booking 12wks & always BP and urine dip a pregnant woman!

Answer 2

* pregnancy induced hypertension if \>20wks * Pre-eclampsia (PET) if HTN and proteinuria \>2O wks * =\> tend to have blunted drop in BP to start with then a rapid increase in BP as PET develops. * Commonly PET arises right at end of pregnancy e.g. 39 wks

Answer 3

HTN & renal disease if \<20wks if \>20wks then its pregnancy induced hypertension and PET NB: *BP decreases and then normalises towards the end of the pregnancy*

Answer 4

* if \>20wks then its pregnancy induced hypertension and PET * NB: BP decreases and then normalises towards the end of the pregnancy * high BP and proteinuria = HTN & renal disease if \<20wks

Answer 5

* HTN/renal disease/PIH * Primiparity (1st pregnancy) * Previous PET (especially early onset or severe) * Obesity * Multiple pregnancies * Afro-Caribbean women

Answer 6

FBC, U&E, renal, LFT, clotting (reflects end-organs affected) protein:creatinine (PCR if raised = significant ,in terms of being nephrotic range proteinuria)

Answer 7

ECG changes due to expanding uterus

Answer 8

1. Lay down stores (anterior abdominal wall, which is used later in pregnancy & in puerperium) 2. make transfer across placenta as efficient as it can be (e.g. increasing gradient)

Answer 9

False. Do not need to eat for 2. Basal metabolic rate rises 350kcal/day in mid gestation e.g. \>20wks, -\> only need the equivalent of an extra mars bar a day 250kcal/day in late gestation --\> 75% to foetus & uterus, 25% to respiration

Answer 10

Weight gain of approximately 10-14kg * Only weigh people at **booking (12wks**) now * Total 10-14kg = * 5kg (***foetus & placenta***) * + 4.5kg (***fat & protein - anterior abdo wall, liver, muscle***) * + 1.5kg (***body water***) + * 1kg (***breasts***) * + 0.5kg (***uterus***)

Answer 11

These rise and cause progressive insulin resistance across pregnancy. BUT the basal insulin level rises in response to keep sugars **normal** (hyperinsulinaemia) -- ***if their pancreas is good enough to keep up*** * the insulin resistance helps to lay down fat stores *(water, foetus and placenta, fat on: liver, abdo wall and muscle & breasts and uterus)* and create glucose concentration across the placenta * - babys sugars mirror their mums - babys dont need to make insulin

Answer 12

The 2nd trimester of pregnancy for foetal reserves (\>13wks)

Answer 13

these are building the maternal reserves and this happens in the first trimester of pregnancy \<12wks

Answer 14

* pregnant women breathe more **_DEEPLY_** - their minute volume increases 40% (e.g. increased gas exhaled/inhaled from persons lung in one minute) * ***increased resp centre sensitivity to CO2*** * increased displacement of ribcage upwards * (breathing deeper \> not noticeably more frequently) * **increased PO2 and decreased PCO2 facilitates placental gas transfer** *

Answer 15

in pregnancy there is increased appetitie and thirst there is **decreased gut motility** =\> progesterone relaxes SMC! (*along with mineralocorticoid effect and CVS changes & breast development)* * **--\> constipation,** * **--\> LOS relaxation and acid reflux (also from up-pressure from uterus)** *(oestrogen develops breast and cvs changes too but also uterine hypertrophy and metabolic changes e.g. insuling resistance)*

Answer 16

SMC relaxation of urinary tract * progesterone relaxes SMC

Answer 17

* ↑urination (& clearance of creatinine, urea, ureic acid) due to * **↑blood flow** (vasodilation) to **kidney** & **filtration** * **↑fluid in body** *(foetus, placenta, amniotic fluid, plasma volume, mammary glands, uterine muscle, oedema)* * Expanding **uterus presses on bladder**

Answer 18

1. fundus - * uppermost thicker muscle --\> push out 2. corpus - * lined by decudia, vascular --\> survival of baby + helps push out 3. Isthmus (lower segment) - * full formed at 36 wks, circular and longitudinal smooth muscles. * Muscle tone & sotened pelvic floor muscles allows presenting part to move to lower segment @36weeks --\> path out uterus 4. Cervix = effaced and dilated during labout, mucous plugs stops ascending infection (+acidity of vagina)

Answer 19

1. ↑muscle mass & blood flow (oestrogen effect) – top e.g. as fundus needs to push out 2. Thin funnel & passage out for foetus – lower uterine segment (cut here in caesarean sections!) * *muscle tone & softened pelvic floor muscles allows presenting part to move to lower segment at 36weeks --\> path out uterus*

Answer 20

function of cervix is to retain pregnancy * **↑vascularity** * Prepares for **expansion:** * **tissue softens,** * CT breakdown * **Proliferation of glands & mucus: anti-infective** (stops ascending infection; along with acidity of vagina)

Answer 21

_rapid fall in steroids on delivery_ (e.g. as progesterone, oest and oestrdiol etc become placental from 9w onwards) * --\> Endocrine-driven changes return to normal rapidly * Uterine muscle rapidly loses **oedema but never returns to pre-pregnancy size** * **Prolactin action on breast INCREASES!**