Pregnancy Flashcards
describe the terminology of a fertilised egg from day 1 to 6
zygote early cleavage (4 cell stage) morula (3-4 days) blastocyst (4-5) implantation
what are the 5 steps of early implantation
shedding of the ZP pre-contract blastocyst orientation apposition cellular contracts adhesion penetration of endometrium
what is medawar
fetal allograft survival
the foetus has protection against the body immune reposes such as placental protection
antigenic immaturity
altered host immunity
describe the response between trophoblasts and the decidua in terms of immunity
you have villous trophoblasts which are inert and do nothing
extravillous and invasive which contain only class 1 human leucocyte antigens
less attractive to cytotoxic T cells
enables binding to NK cells
what is the type of NK cell present in the decidua
CD56 bright
what produces hCG (glycoprotein)
trophoblast cells
what is the role of hCG
luteotrophic - continues to stimulate the corpus luteum for foetal survival
its production is independant of the hypothalamus and pituitary
what is thought to be the cause of morning sickness
production of hCG
what can hCG be used for
pregnancy test - immunoassay detects beta subunit of hCG
what can you see about the foetal development in weeks 5-8 in terms of imaging
5 wks: gestation sac
6 wks: fetal pole, yolk sac
7 wks: fetal heart activity
8 wks: fetal limbs, movements
what percentage of fertile women have at leats one miscarriage
25%
what happens to the likelihood of a miscarriage as you get older
increases
what is the management of miscarriage
progesterone receptor antagonist (mifepristone) with a prostaglandin analogue (misoprostol)
even after 3 miscarriages what is the chance of having a baby
70%
what is an ectopic pregnancy and how common are they
implantation outside of the uterine cavity
1% of all pregnancies
what are possible reasons for rising likelihood of ectopic pregnancy
assisted conception
pelvic inflammatory disease - maybe due to chlamydia
sterillisation reversal
in the management of ectopic pregnancy what is the medical and surgical terminology
medical - methotrexate
surgical salpingectomy
what happens to hCG, oestrogen’s and progesterone during pregnancy up until giving birth (parturition)
hCG increases around 2 months then falls to constant low levels until birth
estrogens increase at a higher rate than progesterone
all three fat to zero at brith
what are the two types of estrogens during pregnancy
estradiol (E2) produced by the corpus luteum and placenta
estriol (E3) produced by foetus and placenta - feta placental unit
what the difference between E3 and E2
estriol has three OH molecules
what are the functions of oestrogen’s
growth/strengthen the myometrium
increase contractile proteins to accommodate growing foetus
increase blood flow through placenta for exchange of waste and nutrients
negative feedback of FSH and LH
stimulation of CBG SHBG and TBG to act as reservoir (hormone binding proteins)
prepare breast for lactation
increase sensitivity of uterus to smooth muscle urotonics such as oxytocin and PGFa oxytocin
what is the function of progesterone
reduces uterine smooth muscle contractility to keep uterus quiescent during pregnancy
inhibits production of PGF2a and oxytocin
blocks T lymphocyte cell mediated responses and cellular immune response
what is human placental lactogen
polypeptide hormone
secreted in increasing concentrations during pregnancy as the placenta grows
what is the function of human placental lactogen
lactogenic and GH like actions
stimulates lipolysis in the mother, increases free fatty acids as energy substrate
inhibits glucose uptake in the mother and favours glucose and protein transport to the foetus
promotes the growth and differential of the breast in preparation for lactation
describe the cascade of reactions that occur due to actions of the placenta
check photos
describe the cardiovascular changes that occur during pregnancy
blood volume 40% increase - including water content and plasma volume
increase in EPO and RBC mass increases
sodium and water retention
mechanism - oestrogen stimulation of RAAS
CO increases by 30-50% (SV 30%) HR (10%)
initial drop in BP then slow increase during the process - drop 0 - 20 weeks then increase back to normal at 40 weeks
what can indicate pre-eclampsia
> 150/90 mmHg persistantly high BP
what are common clinical consequences of pregnancy in association with cardiovascular issue
syncope
haemorrhoids
varicose veins
how is coagulation affected during pregnancy
increased clot formation with decreased clot lysis clotting factors (I, V, VII, VIII, IX, X, XII)
there is increased plasminogen activator inhibitors (less breakdown)
activated protein C resistance
reduced protein S levels
what is the risk of increased coagualation risk in pregnancy
thromboembolism
what are the respiratory changes during pregnancy
increase in O2 consumption
increase in TV, alveolar ventilation, vital capacity unchanged
altered chemoreceptor PsCO2 sensitivity - triggers increase in respiration
what is the clinical consequence of increase in respiratory demand during pregnancy
disproportionate sense of dyspnoea on exertion
what are the changes in renal blood flow during pregnancy
rise in plasma volume and CO
fall in renal vascular resiatnce and increase in renal vasodilatory prostaglandins (PGI2, PGE2)
what is the effect of increased GFR during pregnancy
urea and creatinine fall as no change in production
renal threshold to glucose is diminished
RAAS increased in 1st trimester
what are the clinical consequences of renal changes during pregnancy
deceased bladder capacity - micturition
tendency to UTI’s
what GIT changes are there during pregnancy
cravings
lower oesophageal pressure and incompetence of cardia
decrease in motility - increase in water reabsorption
prolongation of gastric emptying - constipation
what are the clinical consequences of changes to GIT in pregnancy
nausea, vomiting
heartburn
constipation
