Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Obs & Gynae > Physiology of pregnancy > Flashcards

Physiology of pregnancy Flashcards

1
Q

When can bhCG be detected on urine dip to dx pregnancy?

A

2-3wks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How many weeks does it take to be able to identify intrauterine gestational sac on TVUS?

A

~5weeks

@5.5 weeks in TVUS you can see the yolk sac within & embryonic foetus identified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When can you detect foetal heartbeat on TVUS?

A

~ 6 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Pregnancy causes major changes in every bodily system although it is a normal physiological event & everything usually returns to normal after delivery

BUT pregnancy can exacerbate pre-existing conditions & uncover “hidden” or mild conditions such as..?

A
  • hypertension,
  • diabetes (prediabetes → gestational diabetes)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where are the initial pregnancy steroids from?

A

the maternal ovarian (CL) steroids: initial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

From week 7 there are placental peptides. What are these?

A

hCG (like LH)

hPL (like GH)

GH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the placental and foetal steroids?

A

progesterone

oestradiol

oestriol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the maternal and foetal pituitary hormones?

A

GH,

T3,

prolactin (prepare breasts)

Corticotrophin releasing factor (CRF)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What date is term for a baby?

A

37 weeks (although you expect ~40)

e.g. preterm is BEFORE 37 wks!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When does progesterone stop being produced by the corpus luteum?

A

becomes placental from 6-9wks onwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does progesterone do in pregnancy?

A
  • causes SMC relaxation “uterine quiescence”
  • mineralocorticoid (Na resorption and K and H exretion) effect and CVS changes
  • breast development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does oestrogen in pregnancy cause?

A
  • Feto-placental unit
    • [e.g. foetus contributes precursors to some hormones and the placenta finished the hormone development]
  • Development of uterine hypertrophy
  • Metabolic changes (insulin resistance)
    • [for structural and metabolic requirements of foetus and removal of waste productions]
  • CVS changes (fluid gain)
    • [?for provision of amniotic fluid]
  • Breast development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What hormone causes this change in pregnancy?

  • increases from T2 e.g. 13-28 wks
  • insulin resistance
  • & foetal lung maturity
A

cortisol!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What hormone causes these changes in pregnancy?

  • increased from T2 e.g. 13-28 weeks
  • possibly involved in initiation of labour
A

CRH

Corticotrophin releasing hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What hormone causes the following changes in pregnancy?

  • metabolic changes & insulin resistance,
  • some role in lactation
A

HPL - Human placental lactogen

= similar to GH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Where does prolactin come from in pregnancy?

A
  • Predominantly maternal anterior pituitary
    • (anterior pituitary = FLAT PeG)
  • increases throughout pregnancy
  • breast development of lactation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the changes happening with T3/T4/ TSH/TBG in pregnancy and why?

A
  • increase in total T3&4,
  • but same free T3/4
  • most bound due to raised TBG
  • –> thyroxine needed for foetus’s neural development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What rough order do the different hormonesa come into effect to affect pregnancy

  • Oestrogen
  • Progesterone
  • HCG
  • Human Placental Lactogen (like growth hormone)
A
  • HCG peak till 13 weeks e.g. 1st trimester
  • –> PLACENTAL HORMONES:
  • progesterone & oestrogen constantly rising thoughout pregnancy but starts off low
  • HPL (like GH) starts from ~10wks onwards
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Circulating volume during pregnancy increases 40-50% by the end of T1.

How and why?

A

E2 & P act on RAAS for

Na+ & water retention, increased BV from ~5L -> 8.5!

retained water includes: foetus, placenta, amniotic fluid, plasma volume, mammary glands, uterine muscle (less rigid), & oedema –> lungs, CT, ligaments, ankles

20
Q

The normal Haematocrit in non-pregnancy is 130 while in pregnancy it drops to 110-115. What process in pregnancy does this refer to and when should this be tested for?

A
  • the Red cell volume increased during pregnancy but not nearly as much as volume increase (inc. 40-50%) = relative physiological dilution (reference rage TF changes)
  • Dont worry in pregnancy if>100.
  • Check red cell volume at booking e.g. 12 wks - Hb & electrophoresis, 28wks - when dilution is maximal & 36 weeks
  • we check because there is a risk of bleeding during labour & if this is on background of anaemia, problems rise quicker.. we want to optimise health before even if this means transfusing
21
Q

Why do we not worry about the relative physiological dilution of red cell volume in pregnancy?

it normamlly is ~130 and we dont worry about it unless its <100…

A

fHb has a higher affinity for O2, so receives it from maternal Hb

HOWEVER: smoking & carbon monoxide –> foetal hypoxia

22
Q

What are the causes of anaemia in pregnancy e.g. <100? (well 110-115 is normal)–> @ MCV

A
  • Low MCV (TAILS) - <80
    • Iron deficiency (taking iron gives constipation, unpleasant GI SE’s –> if really cannot tolerate oral, give IV),
    • Thalassaemia/sickle cell (find out at booking - inheritance issue if partner also has)
  • High MCV - >100
    • B12/folate
  • Normal MCV - 80-100
    • Chronic disease
    • Marrow issue?
    • Mixed iron/B12/folate deficiency
23
Q

besides relative phsyiological dilution of red cell volume due to fluid increasing/retaining water > inc. red cell volume

What other blood changes occur in pregnancy?

A
  • ↑WBCs,
  • ↑clotting factors making blood hypercoagulable
24
Q

Why are heart problems (among other pre-existing/hidden/mild conditions) exacerbated in pregnancy?

A
  • Cardiac output increases 40-50% in pregnancy…
  • The CO = SV x HR
  • in preg SV increases a lot
    • may get slight LVH to a degree on ECG
  • and HR a bit (only ~9bpm+)
      • overt tachycardia in pregnancy is NOT normal
  • Some peoples hearts dont cope with the increase in CO…
    • those with underlying heart conditions are at risk
    • can uncover or exacerbate a pre-existing problem
25
Q

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?

A

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!

26
Q

why must you always BP and urine dip a pregnant woman?

A
  • 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
27
Q
A
28
Q

A patient is 18 weeks pregnanct and has high BP and protein uria. What does this mean?

A

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

29
Q

A patient is 22 wks pregnant with high BP and proteinuria, what is the cause?

A
  • 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
30
Q

What are the risk factors for PET?

Prevalence of PET is 2-4%;

10% have some hypertensive problem.

A
  • HTN/renal disease/PIH
  • Primiparity (1st pregnancy)
  • Previous PET (especially early onset or severe)
  • Obesity
  • Multiple pregnancies
  • Afro-Caribbean women
31
Q

What blood tests should be done for PET?

A

FBC, U&E, renal, LFT, clotting (reflects end-organs affected)

protein:creatinine (PCR if raised = significant ,in terms of being nephrotic range proteinuria)

32
Q

What test can expanding uterus change?

A

ECG changes due to expanding uterus

33
Q

Metabolic changes occur in pregnancy. What are these?

A
  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)
34
Q

Metabolic changes occur in pregnancy.

Pregnant women should eat for two. True or False?

A

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

35
Q

Metabolic changes occur in pregnancy.

When should pregnant women be weighed and what is the weight change expects?

A

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)
36
Q

What does the progressive rise in cortisol, HPL and E2 across pregnancy do for metabolism?

A

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
37
Q

Which trimester of pregnancy does this change occur in?

  • hPL causes insulin resistance (not “diabetes”, but pre-diabetics experience gestational diabetes)
  • ↑serum glucose, more crosses placenta
A

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

38
Q

What trimester do these changes occur in?

  • ↑insulin from pancreatic β cells
  • Anabolism & glucose into tissue stores
  • ↓serum glucose
A

these are building the maternal reserves and this happens in the first trimester of pregnancy

<12wks

39
Q

Increased oxygen consumption is needed in pregnancy. How is this achieved?

A
  • 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
    *
40
Q

What happens to a pregnant womans appetite/thirst and gut motility?

A

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)

41
Q

Why are pregnant women more prone to increased UTIs?

A

SMC relaxation of urinary tract

  • progesterone relaxes SMC
42
Q

Why do pregnant women pee more?

A
  • ↑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
43
Q

What are the different parts of the uterus?

A
  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)
44
Q

What are the uterine changes?

A
  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
45
Q

What is the function of the cervix?

How do changes help this?

A

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)
46
Q

How does the body start to return to normal after pregnancy?

A

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!

Obs & Gynae (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions