Reproductive 3 Flashcards
What GI physiological changes occur in pregnancy? 4
1) Altered apetite = cravings
2) Decreased oesphageal cravings and incompetent cardia = heartburn
3) Deceased motility = reduced water reabsoprtion and constipation
4) Nausea and vomiting
What is hyperemesis gravidarum?
Excessive nausea and vomiting during pregnancy
What renal physiological changes happen during pregnancy? 5
1) Increased renal blood flow
2) Increased renal vasodilatory prostaglandins (so decreased renal vascular resistance)
3) Increased GFR
4) Ureteric dilation
5) Decreased bladder capacity - increased frequency micturition and a tendency to UTIs
What physiological changes happen to the respiratory system during pregnancy? 4
1) Increased O2 consumption (fetal demands)
2) Increased respiratory compensation (increased tidal volume and alveolar ventilation but no change to vital capacity)
3) Change in control of respiration (altered chemoreceptor and PaCO2 sensitivity) - increased triggers lead to increased respiration
4) Disproportionate dyspnoea on exertion
What physiological changes happen to the coagulation system during pregnancy? 2
1) Increased clotting as increased synthesis of clotting factors
2) Decreased clot lysis - increased plasminogen activator inhibitors from placenta, activated protein C resistance, decreased protein S levels
Why does physiological anaemia occur during pregnancy?
Oestrogen stimulates RAAS and have increased salt and water retention, increasing blood volume by 40%
This is not matched by an increase in Epo of 20%
What happens to BP initially in pregnancy and why and what are the consequences of this?
Get an initial fall in BP, then it rises back up to normal levels
Cardiac output increases by 30-50% (30% increase in stoke volume and 10% increase in heart rate)
But you have a greater fall in total peripheral resistance
So you get an initial drop in BP
The possible consequences of this include:
-Fainting
-Haemorrhoids (venous dilatation)
-Varicose veins
What are 3 signs of pre eclampsia in a pregnant woman?
High BP
Proteinuria
Peripheral Oedema
What is eumenorrhoea?
Normal menstrual cycle
What is oligomenorrhoea?
Disrupted or irregular menstrual cycle
What is anovulation?
Cycle but no ovulation
What is dysmenorrhoea?
Painful menses
What is menorrhagia?
> 80ml blood loss
What is premenstrual syndrome?
Pain and moodiness in pre menses
What is luteal phase depression and what does it normally precede?
Shortened luteal phase with little change in cycle length
It usually pre exists amenorrhoea
What are the hormones involved in the release of progesterone and oestrogen?
Hypothalamus releases GnRH
Anterior pituitary releases the gonadotrophic hormones FSH and LH
Ovaries release the ovarian hormones oestrogen and progesterone
What is secondary amenorrhoea?
No menstruation for >6months
How can low circulating levels of oestrogen lead to bone problems?
Oestrogen is important for bone turnover and formation of bone
Why can athletic hypothalamic secondary amenorrhea occur?
Negative energy balance of >33% alters GnRH pulsatile secretion
Low leptin, Low T3, low neurotransmitters, stress hormones and endorphins all affect GnRH secretion
What changes occur to the blood vessels in the zona functionalis to allow menstrual phase to take place?
Arterial vasoconstriction and hematoma formation causes fissures in the functionalis layer and necrotic outer segments detach
What hormonal change allows the menstrual phase of the endometrial cycle to occur?
With a lack of fertilisation the corpus luteum has no stimulation so degenerates and stops secreting progesterone and oestrogen
The fall in these hormones (particularly progesterone) causes menstrual phase
What happens during the proliferation phase of the endometrial cycle, what days does it run from and to and what hormone is it stimulated by?
Days 3-11
Initiated by oestrogen
Proliferation of stroma and epithelial cells and angiogenesis
Tissue growth of functionalis from 0.5-5mm
What happens during the secretory phase of the endometrial cycle, which hormone is it stimulated by and what days does it run from?
14-28 days
Progesterone maintains wall
Stromal oedema and increased glycogen deposits and lipid deposits
Toward the end of the secretory phase the gradual fall in ovarian hormones causes epithelial cells to release IL 8 and MCP1 which leads to endometrial shrinking
What effect does progesterone have on temperature?
Has a thermogenic effect, increases temperature
Which hormone stimulates follicle growth from day 1 until ovulation?
FSH
On which day does ovulation occurs, stimulated by what hormone and by what mechanism?
Day 14
Stimulated by LH
LH causes follicular hyperaemia - increased pressure and rupture of follicle releasing oocyte
Why do oestrogen levels increase gradually over the within the first half of the menstrual cycle and how does this affect the levels of gonadotrophic hormones?
Oestrogen is produced by granulosa cells of the developing follicle
This causes -ve feedback on LH and FSH production
Until the oestrogen levels reach such a level that is suddenly flips and leads to positive feedback and you get a surge in LH around day 14 causing ovulation (also get a small peak in FSH production)
After the follicle reaches what diameter are LH receptors located on the follicle?
LH receptors located on the cell after >10mm diameter
Why are FSH and LH levels low after ovulation?
Granulosa cells of the follicle become lutein cells in the corpus luteum after ovulation and secrete progesterone and oestrogen which has -ve feedback on the gonadotrophic hormones FSH and LH
Why does the corpus luteum degenerate towards the end of the cycle?
Needs fertilisation of an egg to survive
What 5 things in terms of the immune system are important to fetal survival?
1) Ag immaturity
2) Placental protection
3) Blocking fetal Ab
4) Immune privilege
5) Altered host immunity
How many days post fertilisation is the blastocyst ready to implant and how does it do so?
5-7 days post fertilisation
Trophoblas uses integrins and cell adhesion molecules to allow the blastocyst to implant
What hormone is produced by the trophoectoderm which enables the corpus luteum to survive?
hCG
Why is hCG not so important after the 1st trimester?
The levels of oestrogen and progesterone produced by the placenta rise and therefore hCG not needed to stimulate the survival of the corpus luteum
What sub unit is shared by FSH, LH, hCG and is detected in pregnancy tests?
Beta subunit
After implantation of the blastocyst how many days does it take to signal back to the mother/corpus luteum?
2-3 days
What local signalling happens after implantation of blastocyst and determines its survival?
Villous trophoblast is inert
Extravillous trophoblast is invasive and produces Class 1 human leucocyte Ag
This is less attractive to cytotoxic T cells but enables binding to NK cells
These natural killer cells are unique to the luteal/secretory phase
They have the capacity to ompede or facilitate implantation
They are the source of decidual cytokines so determine maternal response to pregnancy - they are key to successful implantation
Which cell of the immune system is involved in the local signalling of a blastocyst immediately after implantation?
NK cell
Which type of oestrogen in the most important post menopause?
E1, oestrone
Which oestrogen is the main type involved in the menstrual cycle and what is it produced by?
E2, oestradiol, produced by the corpus luteum and the placenta
Which type of oestrogen in the most important in pregnancy and what is it produced by?
E3, oestriol, produced by fetus and placenta
What hormones does oestrogen cause the release of in pregnancy for what function?
Causes anterior pituitary to secrete prolactin for growth and development of breast tissue
What is the function of the oestrogen produced in pregnancy? 7
1) Increased growth of myometrium
2) Increase in contractile proteins
3) Increased blood flow through the placenta
4) -ve feedback for FSH and LH
5) Stimulation of binding proteins that act as a reservoir - CBG, SHBG, TBG
6) Preparation of breasts for lactation
7) Increased sensitivity of uterus to smooth muscle uterotonics towards term (PGF2a, oxytocin)
What is the best way to think of the function of oestrogen during pregnancy?
To get the mother/uterus ready for birth
What is the function of progesterone during pregnancy? 3
1) Reduce smooth muscle contraction - accomodation of foetus
2) Inhibit production of smooth muscle uterotonics (PGF2a and oxytocin)
3) Blocks T-lymphocyte immune response
What is the best way to think of the function of progesterone during pregnancy?
Think of it as keeping the foetus where it is and putting off birth until ready
What is the function of HPL (human placental lactogen) produced during pregnancy? 4
1) Lactogenic and GH like actions
2) Stimulates mother lipolysis (energy source)
3) Inhibits mothers glucose uptake (give glucose and protein to foetus)
4) Promotes growth and differentiation of the breasts in preparation for lactation
What is the best way to think of the function of human placental lactogen during pregnancy?
Involved in post-labour life readiness
What percentage of women have atleast 1 miscarriage?
25%
After 3 miscarriages what is your chance of a successful pregnancy?
70%
How is a miscarriage managed? 3
1) Progesterone receptor antagonist (mifepristone)
2) Prostaglandin analogue (misoprostol)
3) Surgical intervention
These all promote the birth of the deceased foetus
What are the 3 risk factors for ectopic pregnancy?
1) Assisted conception
2) Pelvic inflammatory disease (chlamydia)
3) Sterilisation reversal
Would implantation in a fallopian tube be considered an ectopic pregnancy?
Yes
How is an ectopic pregnancy managed and why? 2
Longer the pregnancy = greater the risk of internal bleeding
1) Methotrexate is specific for mitotic trophoblast
2) Surgery = salpingectomy
Why does blood volume increase by 40% in pregnancy?
Oestrogen stimulates the RAAS and you get salt and water retention
