Learning Objectives (Non-Clic) Flashcards
Name the two primitive duct systems that males and females have in early embryo.
- Wolffian
- Mullerian
Which primitive duct system develops, and which degenerates in males?
- Develops into reproductive tract = Wolffian
- Degenerates = Mullerian
(Opposite in females)
Describe the development of male reproductive system in terms of hormones.
- Testosterone (stimulated by human chorionic gonadotropin from placenta) released from foetal testes
+
Mullerian inhibiting factor (induces regression of mullerian ducts)
Define estimated date of delivery.
40 weeks from the first day of the LMP
Reality gestational age is 14 days less as ovulation is at day 14 of cycle
Define the following times of delivery:
a) At term
b) Pre-term
c) Post-term
a) 37-42 weeks
b) before 37 weeks
c) after 42 weeks
Describe the role of prostaglandins in parturition.
- synthesised within the human fetal membranes (the amnion and the chorion)
- kept within the membranes
- During pregnancy membranes are intact and prostaglandins are not released
- in labour, the membranes not intact, prostaglandins released, ripen the cervix
- also used for induction of labour (PGI2)
Describe the role of relaxin in parturition.
- Causes relaxation of the ligaments in the pelvis (relaxation of the pelvic floor)
- Softens and widens the cervix
- Produced by the ovaries and placenta
Describe the role of oxytocin in parturition.
- Produced by the hypothalamus
- Secreted by the posterior pituitary
- Causes contraction of the uterus (increases production of the prostaglandins)
What are the two things that are required for successful labor?
- Dilation of the cervical
- Contractions of the uterine myometrium
State the 3 stages of labour.
1- Onset of regular contractions to fully dilated cervix - Cervical dilation
2- Delivery of baby - Fully dilated cervix to birth (around 1 hour)
3- Expulsion of the placenta and the membranes (Up to one hour)
Describe the two phases of the first stage of labour.
Stage = Onset of regular contractions to a fully dilated cervix
Phase 1 = Latent Phase
- Regular contractions
- Cervical effacement and dilation to 3-4cm
Phase 2 = Active Phase
- Increase in the frequency of contractions
- Cervical dilation to 10cm
Describe the second stage of labour.
Stage = full cervical dilation to birth
- increase in frequency of contractions
- the presenting part descends
- Baby moves from cervix into vagina
- Stretch receptors in the vagina cause abdominal wall contractions which augment the uterine contractions
- Ferguson Reflex takes place = when the pelvic floor stretches increases release of oxytocin which increases uterine contractions which in turn causes more pelvic floor stretching and more oxytocin
Describe the third stage of labour.
Stage = Expulsion of the placenta and membranes
- Contraction of the myometrium afterwards prevents haemorrhage by constricting blood vessels at site of placenta attachment
What is the name of the shrinkage of the uterus to pre-pregnancy size?
Post-partum involution (takes 4-6 weeks, fall in oestrogen and progesterone levels)
What is meant by full dilation?
Dilation to 10cm
What is a key trigger of labour?
- Estrogne synthesis form placenta –> increase in estrogen receptors in myometrium
- Oestrogen -> Increase in gap junctions (coordinated contraction of cervix) and increase in oxytocin receptors (increased sensitivity)
- Oestrogen -> increase in PG’s -> increase oxytocin receptors and softens cervix
What are the stages of breast physiological development?
- Birth - lactiferous ducts without alveoli
- Puberty - lactiferous ducts + alveoli (alveoli is a lobule which is made out of milk producing glands)
- During pregnancy - estrogen, progesterone, prolactin leads to glandular tissue replacing adipose tissue
- From week 16 - fully developed but in quiescent awaiting activation
Which hormone stimulates duct development during pregnancy?
Oestrogen
Which hormone stimulates Lobule development during pregnancy?
Progesterone
Which hormones stimulates the production/synthesis of milk?
Prolactin
a) Name the two cells which are involved in lactation and secretion of milk.
b) state the hormones that stimulate these cells respectively.
1- Secretory alveoli/acini cells - produce milk stimulated by prolactin
2- Contractile myo-epithelial cells surround each alveolus stimulated by oxytocin
Why does prolactin have no effect on lactation before parturition?
Oestrogen and progesterone levels are high prior to parturition
These hormones inhibit the effects of prolactin
Explain the neurohormonal reflexes that control milk production during lactation.
Suckling -> Mechanoreceptors in nipple stimulates -> hypothalamus stimulated -> decrease in prolactin-inhibiting hormone and increase in prolactin-releasing hormone -> stimulates the anterior pituitary -> increase in prolactin -> stimulates milk secretion
Suckling -> Mechanoreceptors -> hypothalamus -> nervous pathway stimulates the posterior pituitary -> Increase in Oxytocin -> contraction of myoepithelial cells around alveoli -> milk ejection
What happens to milk production after weaning?
No suckling -> no oxytocin -> no milk ejection -> build up of milk -> pressure build up acts directly on epithelial cells -> no milk
No suckling -> no prolactin -> no milk
What is the recommendation period for exclusive breast feeding?
6 months
What is colostrum milk?
the first milk that is secreted by the mammary lobule/glands after birth
Rich in antibodies
Which antibodies are found in Colostrum?
IgG
IgA
A) When does colostrum change into mature milk?
B) Describe Colostrum in comparison to mature milk.
a) after 21 days
b)
Colostrum
- Lower Calories 58 vs 70
- Lower carbs (5.3 vs 7.4g) and fats (2.9g vs 4.2g)
- Higher protein (3.7 vs 1.3g)
- More zinc and sodium
- More fat-soluble vitamins
- Greater amounts of immunoglobulins (IgG and IgA) and a number of growth factors - conferring passive immunity
Which pulmonary cells produce surfactant?
- Type II Pulmonary Cells
Reduces surface tension of the alveoli so lungs do not collapse
How does a baby begin to breath?
- Within 1 minute
- They are in asphyxiated state then there is a stimulus from the suddenly cooled skin
Usually a baby begins to breath in the first minute, however if this does not happen, why may they start breathing in the following minute if there are no other problems?
No breathing in the first minute –> baby hypoxic + hypercapnic –> stimulus enough to begin breathing in the following minute
List causes of delayed breathing of the baby after birth.
These lead to the depression of the respiratory centre
1- Anaesthesia in the mother crossing over to the baby’s system
2- Trauma during delivery (prolonged hypoxia)
3- Prolonged delivery (prolonged hypoxia)
4- Hypoxia during delivery (compression of umbillical cord, premature separation of placenta, excessive contractions of the uterus)
After how long would brain lesions and permanent brain damage develops while a baby is hypoxic?
- 8-10 minutes
Describe respiratory distress syndrome.
- Most common in premature babies
- due to inadequate quantities of surfactant
- Many premature babies cannot produce sufactant
List risk factors for New-born respiratory distress syndrome.
- Diabetic mother
- low weight baby
- premature baby with immature lung development
After oxygenated blood is transferred through the umbilical vein, which organ does it bypass through the ductus venosus?
Liver
Explain why an infant loses weight during the first few days of life.
▪ Fetus feeds on mothers glucose
▪ When that is gone, infant uses stored protein and fat as energy source until milk is avaliable
▪ Takes few days for mother’s milk to develop
▪ Fluid turn over of a baby is 7 times that of an adult
Infants weight decreases 5 to 10% and sometimes as much as 20% within first 2-3 days of life due to loss of fluids
What is the normal neonate Respiratory Rate?
40bpm
Give details of how new-born blood volume changes in the first few minutes and hours after birth.
Blood volume = 300ml at birth –> stripping of umbilical cord means more blood into neonate –> 375ml –> in next few hours fluids enters tissue –> increase in hematocrit but decrease in volume to 300ml again
Explain how plasma bilirubin concentration changes over the first few days after birth.
▪ Rise from 1mg to an average of 5 mg/dl in the first 3 days : physiological hyperbilirubinemia –> mild jaundice
This is because the liver is not developed enough to conjugate a lot of bilirubin
What is Erythroblastosis Fetalis?
Hemolytic anemia in the fetus (or neonate, as erythroblastosis neonatorum) caused by transplacental transmission of maternal antibodies to fetal red blood cells. The disorder usually results from incompatibility between maternal and fetal blood groups, often Rho(D) antigens.
- Jaundice, reduced muscle tone, and hepatic encephalitis, and potentially learning disabilities maybe caused
Give brief details about how immature kidneys can lead to fluid and/or acid/base disturbances in the neonate.
- Metabolic rate twice as high
- Twice as much acid formed
- immature kidneys can only concentrate urine 1.5 time blood plasma unlike adults where it is 3-4 times
- There is marked fluid turnover
- Tendency towards acidosis, dehydration, and rarely over hydration
List four effects of deficient liver function in the neonate.
- Poor conjugation of bilirubin –> small amount of bilirubin is excreted
- Low blood plasma protein concentration due to poor plasma protein formation (can lead to hypoproteinemic edema)
- Deficient gluconeogenesis –> drop in blood glucose levels –> depend on stored fats for energy until proper feeding commences
- Deficient blood factor formation for coagulation
How does digestion and absorption and metabolism differs in neonates compared with older children?
- Deficiency in secretion of pancreatic amylase
- Reduced fat absorption from GI tract (so if you feed cow milk it might be poorly absorbed)
Briefly, explain the body temperature changes in the first approx. 12 hours after birth.
▪ Body surface area is large in relation to body mass, heat is readily lost from the body
▪ This occurs in the first few hours
▪ Returns to normal in 7-10 hours
Premature babies lose heat even faster.
Briefly describe key nutritional needs of the neonate in the early weeks of life.
- Need calcium for rapid bone ossification and vitamin D required for the absorption of the calcium
- Need iron in their diet (usually store it from mother for 4-6 months but incase she is deficient) to make RBC
- Need vitamin C - required for formation of cartilage and intracellular structure (prescribe orange juice if deficient)
Explain how the new-born’s immunological state changes over the first few months of life.
▪ By the end of the first month, there is decrease in gamma goblins (which contain antibodies) up to half - and as such decrease in the immunity of the neonate
▪ Concentration of gamma immunoglobulins returns to normal by the age of 12-20 months.
▪ Mothers immunoglobulins protect the baby from major infections (diphtheria, measles and polio) up till 6 months of age
Describe physiological haematological changes during pregnancy.
- Hb declines (110 -> 105 -> 100g/l) increase in RBC but bigger increase in plasma
- Rise in white blood cells (neutrophils)
- Fall in platelets (gestational thrombocytopenia) - due to increase in plasma not pathological
- Rise in fibrinogen and factors VIII, IX, X - hypercoagulable state
What is the normal platelet count?
150-450 x10 to the 9 /L
Where is thrombopoietin produced?
Liver
Under what platelet level does a person start bleeding easily, and having nose bleeds etc…?
under 50x10 to the 9
Which of the following conditions is life-threatening:
Immune Thrombocytopenic Purpura
or
Thrombotic thrombocytopenic purpura.
TTP
Describe the pathophysiology of Immune/Idiopathic/Autoimmue thrombocytopenic purpura.
- Autoimmune condition
- Antibodies are produced which destroy platelets leading to a low platelet count
- Presents with bruising/rash but also risks bleeding and haemorrhages if platelet count gets low enough
Who does immune thrombocytopenic purpura affect?
Children and adults
Some risk of neonatal thrombocytopenia due to IgG antibodies crossing placenta
Describe the management of immune/idiopathic thrombocytopenic purpura.
- Watch and wait as it is usually self-limiting (treatment is needed if the mother is lower than 50 on platelet count as that is required for labour)
- Steroids (Predinsolone)
- IV immunoglobulins (these IG’s bind to the immune cells that would usually attack the platelets to stop them from doing so)
- Splenectomy
Describe the pathophysiology of Thrombotic Thrombocytopenic Purpura.
- Syndrome characterised by microangiopathic haemolytic anaemia and thrombocytopenic purpura
- This is because very small vessels form clots from platelets
- This is due to deficiency in ADAMTS13 enzyme which usually inactivates/cleaves Von Willebrand factor/polymers that allow platelet aggregation (without the enzyme there is abnormally large VW factors)
- This leads to clots forming in small vessels as they adhere to the vessel wall
- Leads to low platelet count else where
A) What are the symptoms of TTP?
B) Describe management.
A) Pentad of: Fever, renal failure, haemolytic anaemia, neurological abnormalities, and thrombocytopenia - coagulation screen usually normal (and a rash) (So you need to check haemoglobin and platelet count plus clinical features, not all patients have the whole pentad)
B) Treated with plasma-exchange therapy (to replace the enzyme) and corticosteroids
A) What period in and around pregnancy is classified as high risk/hypercoagulable state?
B) Name additional risks.
C) What condition can occur as a result of this state?
A) Through out pregnancy and 6-weeks post-partum
B) smoking, age, previous clot, obesity, twins
C) thromboembolic disease like PE, DVT
During late pregnancy it is normal to have leg swelling as the pelvic veins are compressed by the uterus. How do you differentiate normal leg swelling from a DVT?
If the swelling is:
- Unilateral
- Tenderness
- Progressive pain
What do you do if you suspect a DVT in a pregnancy woman?
1- Doppler exam of leg
2- Chest X-ray
3- if X-ray abnormal then CT pulmonary Angiogram (CTPA) higher radiation dose but more reliable than V/Q scan
(Note- D-Dimer unhelpful as it is raised in pregnancy)
Which anticoagulation medication do you use for Thromboembolic disease?
Low Molecular Weight Heparin (monitor anti Xa levels 3-4 hours after dose to show effective dosing)
- No Warfarin as it is contraindicated
- No DOAC’s as it is not licensed
List symptoms of Pre-eclampsia.
- Hypertension
- Proteinuria
- Fluid Retention (oedema)
- Epigastric pain due to liver swelling
- Headache
- Visual Disturbances
- Urate high
What is the greatest risk factor for HELLP syndrome?
Pre-eclampsia
What is HELLP Syndrome?
- Haemolysis
- Elevated liver enzymes
- Low platelets
(Management = delivery)
A) What is Disseminated intravascular coagulation?
B) What are the risk factors for this condition during pregnancy?
C) Describe the treatment of this condition.
A) Systemic activation of the coagulation cascade which results in the deposition of the fibrin and platelets plugs within the vessels
B) (this is generally set off by infection, injury or illness, burns etc..) Placental abruption, Amniotic fluid embolism (amniotic fluid gets into circulation and get into lungs and cause problems and can set off coagulation cascade), dead foetus
C) Treat the cause, use coagulation factors and platelets
In terms of blood groups, what does someone with blood group O have on their blood red blood cells?
- H Substance only
Which antibody/immunoglobulin is usualyl present against the A or B antigens found on red blood cells with those blood groups?
IgM (Does not cross the placenta)
E.g. someone with group A blood, they have A antigens on their cells and have Anti-B antibodies present in their blood
If someone is Rhesus Negative, which antigen do they lack?
- Antigen D
some people will have naturally occurring antibodies but can develop in response to pregnancy
What is haemolytic Disease of the Newborn?
Mother produces IgG antibodies as some of the child’s blood crosses over to hers which stimulate this, the antibodies then cross to the foetus and cause anaemia, jaundice, brain damage, foetal death
What test looks for fetal cells in maternal circualtion?
Kleihauer test
How do you manage haemolytic disease of the new born in neonates?
- Clinical assessments
- Blood count and reticulocytes/group/red cells/antibodies/billrubin etc…
- Allow antibodies to decline
- Phototherapy to increase bilirubin conjugation
Describe haemoglobin structure/
- 4 folded chains
- 2 alpha (chromosome 16)
- 2 beta chains (chromosome 11)
- each chain has one haem molecules with iron in the middle of it
- the central iron atom is what the oxygen attaches to.
State the globin chains in the following haemoglobin:
1) Hb A (adults)
2) Hb A2
3) Hb F (Foetal)
1) 2 Alpha, 2 Beta
2) 2 Alpha, 2 Delta
3) 2 alpha, 2 gamma
1) What is meant by haemoglobinopathies
2) give examples of haemglobinopathies
1) An issue with the haemoglobin
2) Sickle cell, thalassaemia (this is any globin chain imbalance)
List haemoglobinopathy conditions that cause significant disease / are transfusion dependent .
1- Sickle cell homozygous (in this condition they produce Haemoglobin S which causes RBC to be sickle shaped - chronic anaemia - typically in african caribbean and occasional cases in middle east - sickle cell crisis causes small vessels in bones first to be blocked and pain all over) - management by managing symptoms and pain from sickle cell crisis and transfusion
2- Sickle Cell with Hb C/D/E/Beta thalassaemia (sickle cell with co-inherited condition - same severity)
3- Beta thal homozygous (tansfusion dependent condition not from birth as they have alpha chain and gamma chain but from birth they cant make beta chains for adult haemoglobin so they become considerably anaemicat few months of age)
4- Alpha thal 3 gene deletion (Hb H) (transfusion dependent state - deletion of two genes will be not a problem as the person is barely anaemic but three you require transfusions at set intervals in time)
How do you detect haemogloinopathy/thalassaemia carriers during pregnancy?
1- Screen for ethnic origin (mediterranean, asian, african)
2- Most will be microcytic e.g. mean cell volume <80 and mean cell Hb (MCH) <27
3- Cellulose acetate Hb electrophoresis (not used much now - but Hb electrophoresis is to identify types of Hb in blood)
4- High performance Liquid Chromatography (HPLC) - to separate a mixture of compounds in analytical chemistry and biochemistry so as to identify, quantify or purify the individual components of the mixture.- Gene copy number
6- Gene sequences
Using HPLC, how would the following haemoglobinopathies show:
1) Beta Thalassaemia heterozygous.
2) Alpha thalassaemia with one gene deletion
3) Alpha thalassaemia with two deletions
1) Low MCV and MCH and Hb A2 >3.5%
2) No change
3) low MCV
A) Describe Pre-natal screening in low prevalence areas for haemoglobinopathies.
B) what happens if the foetus is at risk of serious Hb disorder?
A)
1- FBC at booking to check if MCH is <27pg
2- fill in questionnaire on ethnic origin for both partners
3- if either is positive then HPLC is done to look for thal/haemoglobinopathy
B)
- 11-14 weeks chorionic villous sampling foetal DNA or 15 weeks+ amniocentesis
What is the differential diagnosis for a maculopapular rash during pregnancy? (Congenital and peri-natal infections)
- Rubella
- Measles
- Parvovirus
Name a cause of a vesicular rash during pregnancy.
Chicken pox