Reproductive 2 Flashcards
What could be wrong with the 3Ps to cause an abnormal labour?
Power - inadequate uterine contractions
Passenger - Size/Position/Distressed/Multiple
Passage - Pelvic dimensions
What are Neville-Barnes and Keillands forceps?
Traditional metal forceps
What are Ventouse forceps?
Sucker
What is a breech delivery?
Feet first or bum first
What are the 2 non pharmalogical analgesics for pregnancy?
TENS (electric current)
Water birth
What are the 2 first line drugs in early pregnancy?
1) Paracetemol
2) Weak opioids eg. Codeine
After first line drugs as pregnancy progresses what analgesic is offered and what are the side effects (3)?
Nitrous oxide
Side effects include, dizziness, nausea and amnesia
After nitrous oxide, in advancing labour what drug is offered and what are the possible side effects (4)?
Opioids - diamorphine
Side effects include sedation, nausea, vomiting, respiratory depression
In advanced labour what analgesics are offered?
Regional
1) Spinal
2) Epidural
3) Combined spinal and epidural
When would general anaesthetic be used in labour?
Emergency C section when mum/baby is in serious danger
What is significant about the a babies lungs straight after birth?
They are filled with fluid
What happens to the pulmonary vascular resistance and surface area for gas exchange with the first breath?
Vascular resistance decreases
Increase in surface area for gas exchange
The placental blood flow ceases within about 3 minutes, why?
Oxygenated blood is now reaching the left atrium and left ventricle and through the descending aorta reaches the umbilical arteries
Oxygenated blood stimulates the contraction of the umbilical arteries
Results in a reduction in placental blood flow which then ceases completely
Other than contraction of umbilical arteries what 2 other foetal adaptations cease to function?
Increase in pulmonary venous return closes the foramen ovale and the ductus arteriosus
How long does it take foetal haemaglobin to become adult haemaglobin?
weeks
In newborn resusscitation what are the stages?
1) Dry the baby and wrap in towel
2) Assess breathing and heart rate
3) Until the chest starts moving give 5 inflation breaths
4) Once chest starts moving, if heart rate is not detectable or slow start chest compressions, 3 compressions to each breath
What is the average length and thickness of the placenta?
22cm long
2-2.5 cm thick
How much approx does a placenta weigh?
500g
How long is the umbilical cord and what does it contain?
55-60cm long
Contains 2 umbilical arteries and one umbilical vein
What are the 5 broad functions of the placenta?
1) Nutrition
2) Excretion
3) Immunity
4) Endocrine
5) Defence
What is the endocrine role of the placenta? 4 hormones
Manufactures steroid hormones (oestrogen and progesterone)
Makes human placental lactogen (hPL)
Makes human chorionic gonadotrophin (hCG)
What is the role of the palcenta in defence?
Protects from the mothers immune system
What is the role of hCG in terms of the corpus luteum?
hCG ensures that the corpus luteum continues to secrete progesterone and estrogen until the placenta can produce sufficient amounts itself
What is the role of human placental lactogen?
Promotes mammary growth in perparation for lactation in the mother
Regulates maternal glucose, protein and fat levels so that this is always available to the fetus
What is the role of the oestrogen produced by the palcenta?
Causes breasts, uterus and external genitalia to enlarge in preparation for lactation and accomodation of the growing fetus
Causes relaxation of ligaments which will ease vaginal birth
What is the role of progesterone produced by the placenta?
Maintain endometrial lining of the fetus during pregnancy
Prevents pre term labour by reducing myometrial contractions
What is the shape of a term uterus compared to a none pregnant uterus?
Term uterus = Ovoid and erect
Non-pregnant = Flattened pear
How does a term uterus increase in size?
Hypertrophy of the myocytes
At how many weeks does the placenta take place?
6 weeks
How does a placenta form and how is a connection made between the circulation of the mother and the foetus?
Syncitiotrophoblast invade the endometrial wall
Projections of villi make contact with a spiral arteries of the mother and should make nice and smooth connections
What is placenta previa?
Placenta too close to or over the cervix
Need a clearance of 3 cm
What is pre eclampsia?
Get abnormal connections that aren’t smooth between other and foetal circulation
Get a systemic inflammatory response in the endothelium of mother’s entire circulation so get a high BP
From what week is foetal ling surfactant produced?
24
What is foetal lung surfactant made up of?
Phospholipids - PC and PG
Apoproteins - SP-A, B, C, D
Which hormones stimulate the production of fetal lung surfactant?
Fetal glucocorticoids Thyroid hormones (less so)
What are the 2 therapies for infant respiratory distress syndrome?
1) Antenatal steroids
2) Neonatal artificial surfactant
How is an electrical potential generated in the myometrium and how is it spread?
- Any cell can act as a pacemaker
- Depolarisation mediated by calcium ions
- intercellular gap junctions
- intracellular Ca2+ channels and Ca2+ stores
How does the propagation of electrical potential in the myometrium occur and what does this ensure?
Rapid action potential wave (global)
Slower intercellular calcium wave (slower)
enables coordinated and sustained contractions
What 2 things happen in terms of myometrial activity in preparation for partruition as pregnancy progresses?
Rise in resting membrane potential
Increased intercellular coupling (gap junctions eg. connexins)
What 3 things happen in terms of cervical ripening in preparation for partruition?
1) Reduction in collagen
2) Increase in water
3) Change in proteoglycan composition
Cervical ripening happens through the process of physiological inflammation, how is this mediated?
1) Neutrophils and macrophages in the cervical stroma
2) Leucocytes and other cell types within the cervix release pro inflammatory cytokines eg. IL-1B, IL-6 and IL-8
3) Prostaglandins - PGE2, PGI2, PGF2a
When does membrane rupture normally occur in the majority of women (90%)?
Membranes remain intact until the onset of labour
What is premature rupturing of the membranes (PROM/pre labour) and what is the risk when this happens?
Rupture of the membranes before the onset of labour
Risk of fetal and maternal infection
How is premature rupturing of the membranes controlled?
Managed conservatively
70% establish labour within 24 hours
90% establish labour spontaneously within 48 hours
What 3 things make up a diagnosis of being in labour?
1) Regular painful contractions
2) Progressive effacement and dilatation of the cervix
3) Descent of the presenting part
What is the signalling process which enables a mother to reach term?
Hormones (progesterone, oestrogen, DHEAS,CRH), cytokines and prostaglandins released
Leads to up regulation of oxytocin receptors
CRH is thought to have a role in triggering labour, where is it released from?
Fetal trigger for labour
Released from placental trophoblast into maternal circulation
Levels rise as approach deliver
In abnormal partruition including, preterm birth, placental abruption and failure to progress what is the main risk to the fetus?
Birth asphyxia -> Hypoxic brain injury -> cerebral palsy
What are the 4 consequences of birth asphyxia?
1) Lactic acidaemia
2) Tissue acidosis
3) Hypoxic - ischemic encephalopathy
4) Cerebral palsy
What 3 things increase the risk of birth asphyxia?
1) Low birth weight
2) Long labour
3) Placental function impaired
What problems with 1) Lung, 2) Gut, 3) Brain, 4) eye are associated with pre term birth and contribute to the morbidity associated with pre term births?
Lung - respiratory distress syndrome
Brain - intraventricular haemorrhage (cerebral palsy)
Gut - necrtising enterocolitis (malapsorption)
Eye - retinopathy (blindness)
What 3 treatments reduce the risk of serious consequences in a pre term birth?
1) Ventilation
2) Corticosteroids
3) Artificial surfactant
What are the 4 possible reasons for pre term birth and how do they signal pre term birth?
1) Uterine capacity inadequate
2) Cervical weakness
3) Placental abruption
4) Infection - local/systemic
Signal through the production of cytokines
What management occurs in labour of preterm births to reduce the risk of consequences? 5
1) Fetal heart rate monitoring
2) Fetal scalp pH
3) Monitor ST changes in fECG
4) Expedite delivery by cesarean section or instrumental delivery
5) Prognosis is good if the cord arterial pH is above 7 and BE better than -12 mmol/L
What does the combined pill contain and how does it act as a contraceptive?
Contains oestrogen and progesterone
Prevents ovulation as well as thickening cervical mucous and reducing endometrial receptivity
How does an evra contraceptive patch work?
Combined (progesterone and oestrogen)
Worn 3 out of 4 weeks
Prevents ovulation
How does the nuva combined ring contraception work?
Vaginal ring which is flexible and easily removed
Combined
Worn for 3 weeks then discarded and a new ring is inserted after a week
How does the progesterone only pill work as contraception and what are the 2 possible disadvantages?
Primarily thickens cervical mucous
Also reduces endometrial receptivity
and suppresses ovulation
Disadvantages = requires accurate pill taking and irregular bleeding
What do injectable contraceptives contain, how do they work and how often are the administered?
Progesterone
Primarily prevent ovulation (also thicken cervical mucous and reduce endometrial receptivity)
IM or SC every 8 or 12 weeks
What does the implanon contain, how does it act as a contraceptive and what is the 1 possible disadvantage?
Contains progesterone
Primarily prevents ovulation
also thickens cervical mucous and reduces endometrial receptivity
Possible disadvantage = irregular bleeding
What does the IUS contain, how does it act as a contraceptive and how long does it last?
Contains progesterone
Primarily thicken cervical mucous but also leads to endometrial thinning and suppresses ovulation
Lasts 5 years
What does an IUD contain, how does it act as a contraceptive, how long does it last and what is the possible disadvantage?
Contains copper
Prevents fertilisation by direct effect on sperm - foreign body and causes endometrial changes
Last 5-10 years
Can cause heavy periods
Which continent has the highest birth rate?
Sub saharan Africa
Which country had the highest rate of maternal mortality in 2013?
Sierra Leone
What is the leading cause of maternal death in sub saharan Africa?
Haemorrhage
What is the main intervention put in place to reduce maternal mortality?
Antenatal care
What is the 3 delays model of maternal mortality?
1) Delay in seeking care
2) Delay in reaching care
3) Delay in receiving care
What is one of the main risk factors for increase in maternal mortality in the western world?
Increasing maternal age
