L13: Endocrinology Of Pregnancy And Parturition Flashcards
What are the 2 types of hormones
Lipid base
Protein
Which hormones are lipid base
Oestrogen
Progesterone
Cortisol
Androgen
Which hormones are protein
Gonadotrophic- LH, FSH, HCG
Somatomammotrohpic- prolactin, GH
GNRH, Oxytocin
What are the important hormones in the menstrual cycle
Oestrogen
Progesterone
What hormones are the oestrogen and progesterone under the influence of
LH
FSH
What causes ovulation to occur
LH surge
What structure is left behind in the ovaries when an oocyte ovulates
Corpus luteum
What hormones does the corpus luteum produce
Oestrogen
Progesterone
Which hormones causes the corpus luteum to produce oestrogen and progesterone
LH
What happens to the levels of the oestrogen and progesterone as corpus luteum degrades into the corpus Albicans due to no fertilisation
Progesterone and oestrogen decrease
What does the decrease in oestrogen and progesterone cause
Menstruation
If fertilisation/pregnancy has occurred what hormone is produced by the placenta
Hcg
What other hormones does HCG have a similarity with
LH
Which subunit of HCG and LH are similiar
Alpha subunit
When there is hcg what receptor does it bind to
LHCGR on the corpus luteum
If the hcg binds to the corpus luteum LHCGR what does the corpus luteum do
Secrete progesterone and oestrogen to maintain pregnancy
Which layer of the embryo secretes HCG
Syncitiotrophoblast
What are the 3 functions of HCG
Maintain the corpus leteum
Stimulate DHEA production in the fetal adrenal
If males is stimulates testosterone production
Apart from pregnancy what can high levels of HCG indicate
Molar pregnancy
What is a molar pregnancy
Not a real pregnancy, it is a rapidly growing embryonic cell type that can become cancerous tumour
What happens to the HCG levels every 2 days
Doubles
How can we test for pregnancy
By doing a hcg test and looking if it doubles after 2 days
Which cells secrete progesterone
Granulosa lutein cells
Theca lutein cells
In the corpus lutein
What is the function of the progesterone
Maintain the decidua
Relaxes myometrium
If progesterone causes the relaxation of the myometrium what happen when the progesterone levels fall in labour
Myometrium contract
How does progesterone relax the myometrium
Progesterone down regulates the synthesis of contractile associated proteins e.g GAP junctions, oxytocin receptors
What is the main derivative of steroids
Cholesterol
In the placenta what enzyme does it lack that cannot convert progesterone to DHEA
17 alpha hydroxylase
In the fetus what enzyme does it lack that cannot covert pregnelone to progesterone
3 beta hydroxy steroid dehydrogenase
What does these modification in the placenta and fetus result in
Different pathway for oestrogen synthesis
What are the 3 types of oestrogen
E1
E2
E3
What are the types of oestrogen for
E1: after menapause
E2: regulates menstruation
E3: during pregnancy
When implantation occurs what is the main souse of oestrogen
Placenta
Fetal liver
What is the role of oestrogen
- vasodilation
- Increase in prothrombotic mechanism (we don’t give oestrogens contraception to people with blood clots)
- breast development
- increase in contractile associated proteins
What is the most potent oestrogen
E2
Which hormone is produced in the fetus for growth
Placental growth hormone
How does placental growth hormones work
- By modifying receptors that transport glucose from maternal to fetus
- stimulate gluconeogenesis
Which hormone produced in the fetus regulates insulin sensitivity
Human placental lactogen (HPL)
Where is the HPL secreted from
Syncitiotrophoblast
If HPL can drive insulin sensitivity what can it cause
Gestational diabetes
How does the HPL cause insulin sensitivity
By increasing IGF1 in the maternal liver
What other effects does HPL have
Lobuloalveolar development and maturation of the maternal breast
Overall then what is the role of human placental lactogen and placental growth hormone
Increase glucose for fetus
Which addition hormone apart from oestrogen and progesterone does the corpus luteum produce
Relaxin
When does the levels of relaxin increase
In parturition
What is the role of relaxin
Increase cardiac output
Increase renal blood flow
Relax pelvic ligament
During pregnancy which 2 hormones should have a balance
Progesterone
Oestrogen
Why does oestrogen and progesterone have to be balanced in pregnancy
Progesterone is a myometrium relaxor
Oestrogen is a pro-contractile
What occurs in labour to the levels of progesterone
Decrease
In clinical practice what can we give to induce labour
Progesterone antagonist
What are the 2 phases of labour
1) latent phase
2) active phase
What is the latent phase
Cervix is changing by softening, thinning and relaxin is acting on the pubic symphysis
What is the active phase
Strong rhythmic contractions of the uterus to pass baby out
Which phase induces the cervical dilation
Active phase
What produced prolactin
The anterior pituitary gland
When does prolactin increase
During pregnancy
What is the role of prolactin
- prepare breast for lactation
- lung maturation for baby
- milk biosynthesis within the alveolar cells
What after pregnancy i.e the delivery of the baby, what stimulates the prolactin secretion from the anterior pituitary gland
Baby suckling at the nipple
What produced oxytocin
Posterior pituitary gland
What is the level of oxytocin during pregnancy
Low
When does oxytocin levels increase
In labour
What is the role of oxytocin
- myometrium contractions
- maintain uterine contraction after birth to help uterus shrink back
- ejects milk out
Which pro contractile prostaglandin is produced during brith
PGF2 alpha
Does the fetus itself contribute to labour
Yes
Describe how the fetus contributes to labour
1) placental cortical releasing hormone increases
2) DHEA production increases in the fetal adrenal gland
3) DHEA converts into oestrogen in the placenta
4) oestrogen is pro-contractile and initiates contraction of the myometrium
What are the 2 hormones involved in lactation
Prolactin : Produces milk
Oxytocin : milk Out
Which hormone induces the prolactin production in the anterior pituitary gland
Oestrogen
What are the 2 ways oestrogen causes prolactin
- Directly
Or - suppressing dopamine
What happens to the levels of dopamine when the baby suckles on the nipple
Decreases
What are the advantages of breastfeeding
- protects against infection
What are the advantages of breastfeeding to the mother
Contraception i.e lactational ammenorhhea
Reduces cancer risk
Emotional health
Weight loss muscle
