Obs and Gynae Flashcards
Name 3 hormones that are important in pregnancy
- hCG
- Progestins
- Oestrogens
- hPL, Prolactin, Oxytocin also important
Where is hCG produced?
The trophoblast
Give 2 functions of hCG
- It signals the presence of the blastocyst
2. It prevents the corpus luteum from dying (luteal regression)
Where are progestins produced?
Initially from the corpus luteum and then from the placenta from week 7
Give 3 functions fo progestins
- Prepares the endometrium for implantation
- Promotes myometrial quiescence
- Increases maternal ventilation
How do progestins prepare the endometrium for implantation?
Stimulate the proliferation of cells, vascularisation and the differentiation of endometrial stroma
Where are oestrogen produced?
Initially in the ovary and then from a combination of fetal and maternal sources
Give 2 functions of oestrogens in pregnancy
- Promotes uterine blood flow, myocetrial growth and cervical softening
- Increases sensitivity and expression of myocetrial oxytocin receptors
- Increases water renovation and protein synthesis
- Increases breast and nipple growth
- Promotes a change in the cardiovascular system
What is the main oestrogen in pregnancy?
E3 = indicates fetal wellbeing
What is the role of E2 in pregnancy?
Responsible for proliferation of the endometrial epithelium and it also facilitates progesterone action
What is the role of human placental lactose (hPL)?
- Mobilises glucose from fat
- Acts as an insulin antagonist
- Converts mammary glands into milk secreting tissues
Where is prolactin produced?
Anterior pituitary gland
What is the role of prolactin?
Responsible for milk production
Where is oxytocin produced?
Posterior pituitary gland
What is the role of oxytocin?
Responsible for uterine contractions and milk secretion
Where are FSH and LH produced?
Anterior pituitary gland
What is the main basis of the HPG axis?
Hypothalamus releases GnRH that acts on the anterior pituitary gland
Anterior pituitary release FSH and LH that act on the ovaries
Ovaries produce oestrogens and androgens
What cells in the ovaries does FSH act on?
Granuloma cells –> oestrogen production
What cells in the ovaries does LH act on?
Theca cells –> androgen production
What hormone inhibits prolactin release?
Dopamine (released from hypothalamus to act on anterior pituitary)
Are the changes that occur during pregnancy pathological or physiological?
Physiological changes occur in pregnancy –> resetting of normal physiological values
Give 2 characteristics of maternal physiological changes
- Anticipatory –> precede fetal demands and growth
- In excess of fetal requirements
- Dynamic –> inter-trimester variation
- All enhance placental exchange of nutrients and waste
What happens to maternal renal function in pregnancy?
- Kidneys increase in size (20%)
- Increase in renal blood flow –> increase in GFR (–> decreased plasma urea and creatinine)
- Increased creatinine clearance, glycosuria, aminoaciduria
- Increased UTI risk (progesterone reduced smooth muscle tone –> urinary statis)
What happens to maternal cardiac output in pregnancy?
Cardiac output, HR and stroke volume increase by 30-50%
How does maternal BP change throughout pregnancy?
Biphasic changes
- 16-20 weeks = decrease in peripheral resistance –> decrease in systolic and diastolic pressure
- Late pregnancy = increase in BP
Why does dilution anaemia occur in pregnancy?
Increase in ECF volume causes dilution effects
There is an increase in RBC numbers but RBC concentration decreases per unit volume due to increased plasma volume level (by 50% by term)
Decreased haemoglobin and haematocrit levels
What happens to white blood cells during pregnancy?
Increase in white cells (polymorphonuclear leukocytes)
NO dilution effect seen
Why does thromboembolism risk increase during pregnancy?
Blood becomes hypercoagulable
- Increase in plasma fibrinogen
- Increase in clotting factors (VII, VIII, X)
- Increase in plasminogen activator inhibitor
How does maternal respiratory function change in pregnancy?
- Increase in maternal oxygen consumption (15-20%)
- Increase in tidal volume –> increases minute volume
- Decrease in total lung volume
Why does maternal PCO2 decrease in pregnancy?
Decreases from 4.7kPa to 4.0kPa
Creates much steeper gradient helping the fetal gas exchange
State of compensated respiratory alkalosis
Increase in maternal DPG –> promotes O2 release at low maternal Hb saturations seen in placenta
What GI and Liver changes occur in pregnancy?
- Delayed gastric emptying
- Cardiac sphincter relaxation –> heart burn
- Increased gut transit time
- Reduced CCK secretion
- Reduced gall bladder motility –> obstetric cholestasis and increased risk of gallstones
What is the principle fetal nutrient?
Glucose
Can the foetus produce any of its own glucose?
No, gluconeogenic enzymes are inactivated int he foetus and so all its glucose has to come from its mother
The foetus also has no mechanism to limit uptake of glucose so will always take up glucose even if excessive
In early pregnancy, is maternal plasma glucose high or low?
Plasma glucose is low as it is being stored (glycogen) and deposited (as fat)
In late pregnancy, is maternal plasma glucose high or low?
Plasma glucose is higher, due to maternal insulin resistance and glucose sparing for the foetus
What are the consequences of maternal insulin resistance?
Maternal insulin resistance –> gestational diabetes –> increased risk of macrosomia and shoulder dystocia
Why is the immune response suppressed in a pregnant last?
Prevention of foetal rejection
Give 4 ways in which foetal rejection is prevented in a pregnant lady?
- A TH2 bias is observed
- Syncytiotrophoblast has self:no-self markers so doesn’t stimulate an immune response
- Extra-villous trophoblast cells have modified markers
- Overall immune response is suppressed
Give 3 potential complications if there is not a TH2 bias in pregnancy
- Pre-eclampsia
- IUGR
- Miscarriage
How does the endometrium epithelium become adhesive to the blastocyst?
The blastocyst and endometrium communicate via the release of hormones –> ‘sticky endometrium’
When is a women’s cycle does the endometrium become ‘sticky’?
Between 20-24 days = window of implantation
What reaction occurs when a blastocyst implants into the endometrium?
Primary decidual reaction
What part of the blastocyst facilitates placental formation?
The cytotrophoblast
What does the cut-trophoblast go onto form?
Anchoring villi –> extra villous trophoblast
What can trigger differentiation fo anchoring villi into extra-villous trophoblast?
Hypoxia
What is the role of extra-villous trophoblast (EVT) cells?
EVT invade and remodel spiral arteries (become wide bore, low resistance)
Leads to more hypoxia so more EVT = positive feedback
Why do EVT cells invade and remodel spiral arteries?
To allow for optimum nutrient delivery and blood supply for the baby
Give 3 potential consequences of poor end-vascular remodelling
- Pre-eclampsia
- Preterm birth
- IUGR
Due to reduced acquisition of maternal blood supply for baby
What happens to the cervix during pregnancy?
Cervix increases in softness and vascularity with increase gestation Blue tinge (oestrogen mediated) = Chadwick's sign
Define Screening
Process of identifying apparently healthy individuals who may have an increased risk of developing a disease
What are the Wilson and Jugner screening criteria?
- The condition should be a serious health problem
- The natural history of the condition should be understood
- There should be a detectable early stage
- There should be a treatment available
- Facilities for diagnosis and treatment should be available
- There should be a suitable test
- The test should be acceptable to the population
- There should be an agreed policy on whom to treat
- The cost of testing should be balanced against the benefits
- Screening should be a continuous process not just a one off
When would a woman have her booking appointment and what is the purpose of it?
Before 12 weeks, often 10 weeks
- Obstetric history and examination
- BMI, BP, urine dip, Hb
- Check for HIV, Hep B, Syphilis, Rubella
- General healthy lifestyle advice
- Screen for complications
When should the dating US be done?
Preferably between 11 to 13+6 weeks
- Dates pregnancy, confirms viability, singleton/multiple and picks up any gross structural abnormalities
- Screening occurs –> Crown-rump length (CRL) and Nuchal Translucency (NT)
- Blood test –> including BhCG, PAPPA, infection, rhesus status
What diseases are screening for in the foetal anomaly screening test?
- Down’s (T21)
- Edward’s (T18) –> LBW, small head/mouth/jaw, low set ears, cleft palate, exomphalos
- Patau’s (T13) –> cleft lip/palate, microcephaly ,ear malformations, rocker-bottom feet
What fetal screening tests can be done?
- Combined Test = first trimester (11+2 to 14+1 weeks) –> maternal age, US CRL and NT, blood sample (PAPP-A and free beta hCG)
- Quadruple Test = second trimester (14+0 to 20+0 weeks) –> Blood test (AFP, total beta hCG, oestriol, inhibin A)
Why is the quadruple test sometimes done?
If combined screening is not possible –> if late booking or NT not obtained
ONLY A MARKER OF DOWNS
When is the anomaly US done?
18+0 to 20+6 weeks
Detects major structural abnormalities
What is the threshold for further testing following a fetal anomaly screening test?
If the risk is >1 in 150 then further testing will be done –> chorionic villous sample (CVS - at 10 weeks) or amniocentesis (at 15 weeks)
(NIPT available privately)
What diseases are being screened for in the antenatal infectious diseases screening test?
- HIV –> treat mum and reduce transmission to baby
- Hep B –> see if mum is infected
- Syphilis –> treat mum to prevent congenital syphillis or possible loss of baby
What is the inheritance pattern of sickle cell and thalassaemia?
Autosomal recessive
Name 3 neonatal screening programmes
- Newborn blood spot
- Hearing test
- Newborn and 6-8 weeks physical examination
What is the neonatal newborn blood spot screening test?
Screens for 9 conditions by a heel prick blood test at days 5-8
- Sickle cell disease (can also identify beta thalassaemia major and carriers of sickle cell)
- Cystic fibrosis
- Congenital hyperthyroidism
- Phenylketonuria
- Medium chain acyl-CoA dehydrogenase deficiency (MCADD)
- Maple syrup urine disease
- Isovaleric acidaemia
- Glutaric aciduria type 1
- Homocystinuria
When is the neonatal hearing test done?
Within 4 weeks
- Looking for a response in the cochlea
When are the newborn physical examinations done?
Within 72 hours of birth and repeated at 6-8 weeks by a GP
Give 4 things that a newborn physical examination is looking for
- Eye problems
- Heart defects
- Hip dysplasia
- Undescended testes
Name 3 risk factors that require serial scans from 28 weeks
- Previous SGA baby
- LGA baby
- Polyhydramnios/oligohydramnios
- Smokers
- BMI >35
Serial scans = US every 3 weeks
Name 3 disorders that are exacerbated by pregnancy
- HTN
- Renal disease
- Cardiac Disease (e.g. mitral stenosis)
- Endocrine disease
Name 3 disorders that are specific to pregnancy
- Gestational Diabetes
- Pre-eclampsia
- Obstetric cholestasis
- Acute fatty liver in pregnancy
How can pregnancy affect anaemia?
2 fold increase in iron requirements and 10 fold increase in folate requirements
IDA = ferrous sulphate
Folate deficiency = folic acid
Multivitamins can be taken –> contain iron and folate
Anaemia is associated with low birthweight and preterm delivery
How is asthma affected in pregnancy?
Affected by physiological changes
Main exacerbation risk in 3rd trimester
Most medications are safe in pregnancy –> SABA, ICS, LABA, theophylline, leukotriene antagonists
Make sure to avoid ibuprofen and BB in labour
If a mother has a cardiac condition when can the baby be screened?
20 week ECHO
What are low risk cardiac conditions in pregnancy?
Mitral incompetence Aortic incompetence ASD VSD PDA
What are high risk cardiac conditions in pregnancy?
Aortic stenosis Coarctations of aorta Prosthetic valves Pulmonary HTN Marfan's with aortic root dilation - Pregnancy often discouraged in these patients
What inheritance pattern is associated with obstetric cholestasis?
Autosomal dominant
What symptoms does obstetric cholestasis often present with?
Itching –> often hands and feet and at night
Can have anorexia, malaise, epigastric discomfort, steatorrhoea, dark urine
What might you see on the blood results of a patient with obstetric cholestasis?
Raised AST, ALT and bile acid
What does obstetric cholestasis increase in the risk of?
Premature and Still birth
How is obstetric cholestasis managed?
LFTs weekly
Ursodeoxycholic acid –> improves liver function and itching
Vitamin K
What risks are associated with hyperthyroidism in pregnancy?
Maternal risk = thyroid crisis with cardiac failure m
Fetal risk = thyrotoxicosis due to transfer of thyroid stimulating antibodies (usually resolves after 6 months)
What hyperthyroidism controlling drug is preferred in pregnancy?
Propylthiouracil (PTU) preferred over carbimazole as less teratogenic
What risks are associated with untreated hypothyroidism in pregnancy?
Early fetal loss and impaired neurodevelopment
Higher dose of thyroxine often needed during pregnancy, especially in first trimester (T4 needed for fetal brain development <12 weeks)
What diabetic medications can be used during pregnancy?
Insulin and metformin are safe
All other oral hypoglycaemics are contraindicated
ACEi and statins also contraindicated
Name 3 maternal complications due to diabetes
- DKA
- Pre-eclampsia
- Progression of retinopathy (screened twice at least throughout pregnancy)
- Hypoglycaemia
Name 3 possible fetal complications due to maternal diabetes
- Miscarriage
- Stillbirth
- Premature labour
- Macrosomia –> shoulder dystocia
- Neonatal hypoglycaemia, hypocalcaemia, polycythaemia
- Polyhydramnios
- Respiratory distress
- Fetal abnormalities
What happens in women with gestational diabetes when extra glucose crosses the placenta?
Insulin, GF and GH’s are produced –> foetal growth is stimulated and fat and glycogen are deposited
How is gestational diabetes diagnosed?
Oral Glucose Tolerance Test at 28 weeks 75mg glucose given - Fasting plasma glucose >5.6 OR - >7.8 after 2 hours
How is gestational diabetes managed?
Diet and exercise = first line
Metformin = 2nd line
Insulin = 3rd line
OGTT 6 weeks postpartum to ensure it has resolved after medications have been stopped following delivery
How can epilepsy in pregnancy be managed?
- Preconception counselling
- Manage triggers and control seizures
- Medications often teratogenic –> sodium valporate (swap to lamotrigine)
- Alpha fetoprotein, anomaly scan, fetal ECHO (22-24 weeks)
- High dose folic acid throughout (before conception if possible)
- Vitamin K from 36 weeks
Name 3 possible fetal complications due to being on sodium valproate during pregnancy
- Nueral tube defects
- ASD
- Cleft palate
- Hypospadias
- Learning difficulties and autism
Define Chronic HTN
HTN diagnosed before pregnancy or before the 20th week of gestation and nor resolved postpartum
Define Gestational HTN (Pregnancy Induced HTN)
New HTN after 20 weeks gestations which resolves after birth
NO proteinuria
>140/90
Define Pre-eclampsia
New HTN after 20 weeks with proteinuria (>0.3g protein/24hours)
What is eclampsia?
Preeclampsia (gestational HTN + proteinuria) and generalised tonic clonic seizures
Describe the pathophysiology behind pre-eclampsia
Spiral arteries do not remodel –> arteries are tight leading to increased resistance in the placenta –> placental ischaemia –> RAAS activated –> poor renal perfusion, HTN, proteinuria and oedema –> pre-eclampsia
Give 4 risk factors for developing preeclampsia
- Previous pre-eclampsia
- Age >40 or teenage
- Primipatiry
- Multiple pregnancy
- Long birth interval (>10 years)
- Existing medical conditions –> HTN, renal disease, Dm, antiphospholipid anitbodies
Give 3 signs of pre-eclampsia that are detected at the kidneys
- GFR and renal blood flow decrease
- Raised uric acid
- Proteinuria
Give 3 symptoms of pre-eclampsia
- Visual disturbances
- Headaches
- Epigastric pain
- Weight gain
- Vomiting
Give 3 signs of pre-eclampsia
- HTN
- Proteinuria
- Retinal Vasospasm
- RUQ tenderness
- Ankle clonus or brisk reflexes
- Oedema
How is preeclampsia classified?
Mild, moderate, severe - Severe = severe HTN (>160/110) and/or symptoms and/or biochemical and/or haematological impairment OR Early = <34 weeks Late = >34 weeks
Management of preeclampsia
- Restrict activity and regular BP, urine and biochemistry checks
- Labetalol (not in asthmatics) +/- nifedipine
- IV MGSO4 (neuroprotection) = reduces frequency of eclampsia
- DELIVERY = CURE
Give 3 indications for delivery in preeclampsia
- Gestational age >38 weeks
- Platelet count <100,000 cells/mm3
- Progressive deterioration in liver and renal function
- Suspected placental abruption
- Persistent severe headaches, visual changes, N+V, epigastric pain
- HELLP syndrome or eclampsia
- Severe fetal growth restriction
- Oligohydramnios
Give 3 possible maternal complications due to pre-eclampsia
- Eclampsia
- CVA
- HELLP (Haemolysis, elevated liver enzymes, low platelets)
- Liver failure
- Renal failure
- DIC
- Pulmonary oedema
Give 3 possible fetal complications due to pre-eclampsia
- IUGR
- Preterm brith
- Placental abruption
- Hypoxia
When and why is aspirin prescribed in pregnancy?
150mg from 12 weeks OD if 1 high risk factor or 2 moderate risk factors
Moderate Risk Factors
- 1st pregnancy
- > 40 y/o
- Pregnancy interval >10 years
- BMI >35 (at first visit)
- FHx of preeclampsia
- Multiple pregnancy
High Risk Factors
- Hypertensive disease in previous pregnancy
- CKD
- AI (like SLE or antiphospholipid syndrome)
- Type 1 or 2 diabetes
- Chronic HTN
Give 2 signs of polyhydraminos
- Increased abdominal size that is out of proportion for weight and gestation (increased SFH)
- AFI >20 on USS
- Maternal dyspnoea and faint foetal heart sounds
Give 3 causes of polyhydramnios
- Maternal diabetes
- Fetal abnormalities (duodenal atresia)
- Multiple pregnancy
Give 3 potential consequences of polyhydramnios
- Cord prolapse
- PPH
- Preterm labour
- IUGR
Describe the 3 stages of labour
Stage 1 = Cervical remodelling, dilation and uterine contractions
Stage 2 = Full dilation to delivery of foetus
Stage 3 = Placental delivery
Describe the 3 stages of labour
Stage 1 = Cervical remodelling, dilation and uterine contractions
Stage 2 = Full dilation to delivery of foetus
- can have a passive hour once fully dilated = contractions slow down
Stage 3 = Placental delivery
What are the 2 phases of Stage 1 labour?
Latent phase = irregular contractions that vary in length and strength, cervix begins to dilate and efface up to 4cm (hours)
Active phase = established labour, stronger and more regular contractions, cervix becomes fully effaced and dilates up to 10cm (primi woman = 0.5cm/hour)
What causes myometrial contractions?
Oxytocin release –> increased intracellular Ca2+ –> myometrial contractions
Name an oxytocin analogue that can induce labour
Syntocin
Name 2 drugs that can inhibit uterine contractions
- Nifedipine (CCB)
2. Atosiban (oxytocin antagonist)
Why can nifedipine inhibit uterine contractions?
It is a CCB so blocks rise of intracellular calcium –> inhibiting muscle contraction
Define Lie in terms of the foetus during pregnancy
Relationship between the longitudinal axis of the uterus and longitudinal axis of the foetus
Can be longitudinal, transverse or oblique lie
Define Presentation in terms of the foetus during pregnancy
Anatomical part of the foetus which presents itself first though the birth canal
Define Position in terms of the foetus during pregnancy
relationship between a defined area of the presenting part (the denominator) and the mothers pelvis
- Occiput = denominator in a fully flexed head
- Chin = denominator in fully extended head (face presentation)
- Brow = denominator in partially extended head (brow presentation)
- Sacrum = denominator in breech presentation
Define Attitude in terms of the foetus during pregnancy
Relationship of the fetal head and limbs to the fetal trunk –> flexed or extended
What are the 3 key participants in labour?
- Passage = maternal boney pelvis and soft tissues
- Passenger = fetus –> size, presentation, postion, anomalies
- Power = uterine contractions and maternal effort
What is cervical ripening?
Increased softening, distensibility, effacement and dilatation of the cervix and occur prior to the onset of labour and in the latent phase
Primiparous = process completed before first active stage of labour
Multiparous - can take place at the same time as dilation
Explain moulding
Overlapping of fetal skull bones during labour to help reduce the size of the head
Briefly describe the mechanism of labour
- Engagement and descent
- Flexion
- Internal rotation = fetal head turns 90 degrees
- Extension = head extends once occiput beneath suprapubic arch
- Restitution = align head with shoulders
- External/lateral rotation
- Delivery of body
Briefly describe the mechanism of labour
- Engagement and descent
- Flexion
- Internal rotation = fetal head turns 90 degrees
- Extension = head extends once occiput beneath suprapubic arch
- Restitution/external/lateral rotation = align head with shoulders
- Delivery of body
Why is there often delayed cord clamping?
Allows baby to transition
Increase in RBC, iron and stem cells
Reduces the need for inotropic support
What are the 2 membranes associated with the placenta?
- Amnion = bag around baby
- Chorion = membranes around the placenta
Need to examine placenta and membranes after to ensure they are intact –> left in can cause severe PPH
When is there shared antenatal care between the hospital and the community?
High risk women
- Underlying medical conditions –> HTN, DM, epilepsy, RA, asthma, ITP
- Complications in previous pregnancy –> Previous CS/preeclampsia/PPH/SGA/preterm/3rd/4th degree tear
- Complications in current pregnancy –> preeclampsia, breech, GDM, multiple, PP
- Issues with women herself –> high/low BMI, smoking, alcohol, drugs, old/young
How are babies monitored antenatally?
- USS
- Intermittent auscultation –> with handheld doppler or pinned stethoscope (listen to fetal heart)
- CTG
What fetal measurements are taken antenatally on US?
Growth/estimated fetal weight measurements
- Abdominal circumference
- Head circumference
- Femur length
Liquor volume (amniotic fluid index)
Umbilical artery dopplers (pulsatility index)
Give 2 methods used for monitoring the fetal heart rate
- Intermittent auscultation –> low risk
2. Continuous monitoring, cardiotocgraphy (CTG) –> high risk patients
During labour when should intermittent auscultations be performed?
Every 15 minutes in the 1st stage
Immediately after a contraction for at least 1 minute or every 5 minutes in 2nd stage
Give 2 disadvantages of intermittent auscultation
- Variability and decelerations can’t be detected
- Long term monitoring is not possible
- Quality of FHR can be affected by maternal HR and movement
Give 2 advantages of continuous monitoring of the FHR
- Gives lots of information –> variability, accelerations, decelerations
- Long term monitoring possible
- Monitors FHR and uterine contractions
CTG: what is a normal baseline HR?
110-160 bpm
CTG: what is a non-reassuring baseline HR?
100-109 bpm
CTG: what is an abnormal baseline HR?
<100bpm or >180 bpm
CTG: what is normal variability
5-25 bpm
CTG: what is non-reassuring variability?
<5 for 40-90 minutes
CTG: what is abnormal variability?
<5 for >90 minutes
CTG: what is an acceleration?
An increase in the baseline HR by 10-15 bpm
Presence of accelerations is reassuring
CTG: what is a deceleration?
A decrease in the baseline HR by 10-15bpm
Presence of decelerations are non-reassuring
CTG: What are early decelerations?
Decelerations seen just before a uterine contraction
They may be due to fetal head compression
CTG: What are late decelerations?
Decelerations seen just after uterine contraction
They may be due to placental insufficiency/hypoxia
They are more concerning than early decelerations
CTG: What are variable decelerations?
Mixture of early and late decelerations
Can often be cord compression
CTG: how would you determine if a CTG was overall normal, suspicious or abnormal?
- Normal = everything is normal and accelerations are present
- Suspicious = one non-reassuring feature
- Abnormal = >2 non-reassuring features and/or >1 abnormal feature
How do you define a normal CTG?
- Baseline HR = 110-160 bpm
- Variability >5
- Accelerations present
- No decelerations
What is the gold standard method for direct FHR monitoring?
Scalp ECG
Give a disadvantage of a scrap ECG for monitoring the HFR
- Invasive
- Membranes need to be broken and cervix >2cm
- Risk of scalp injury and perinatal infection
When is a fetal blood sample taken?
If there is a pathological CTG but don’t want to get baby out straight away (e.g. contracting >4 in 10)
How do you interest FBS samples?
Look at pH or lactate
Normal pH = >7.25
Borderline pH = 7.21-7.24 –> repeat after 30 minutes
Abnormal pH = <7.2 –> consider C section
How do you interpret FBS samples?
Look at pH or lactate
Normal pH = >7.25
Borderline pH = 7.21-7.24 –> repeat after 30 minutes
Abnormal pH = <7.2 –> consider C section
Define prematurity
Babies born alive between 24 and 36+6 weeks
What is preterm labour?
Persistent uterine activity AND change in cervical dilatation and/or effacement before 37 weeks
What organs are most likely to be affected in babies that are premature?
Lungs and the brain
Name 3 things that can be given to a premature baby to increase survival rates
- Antenatal steroids
- Artificial surfactant
- Ventilation
- Nutrition
- Antibiotics
How is preterm delivery classified?
Spontaneous (70%) –> preterm labour, PPROM, cervical weakness, amnionitis
Induced –> medical/obstetric disorder
Give 5 risk factors for having a preterm baby
- Previous preterm birth
- Previous late miscarriage
- APH or other vaginal bleeding
- Multiple pregnancy
- Ethnic group
- Genital infections
- Medical conditions –> HTN, renal disease
- Cervical surgery/weakness
- Lower socioeconomic status
How can preterm birth be prevented?
Progesterone suppositories –> from early pregnancy for those at high risk
Cervical cerclage –> sutures in cervix to keep it closed
Screen for STIs and UTIs
Manage medical disease
How is preterm birth managed?
Steroids Tocolysis (nifedipine or oxytocin receptor antagonist - atosiban) = prevent labour and delivery MgSO4 = neuroprotective if given <34 weeks
What is preterm prelabour rupture of membranes (PPROM) commonly associated with?
Chorioamnionitis = bacterial infection that occurs before or during labour
How do you manage PPROM?
If evidence of chorioamnionitis = steroids, deliver whatever the gestation, broad spectrum Abx
If NO evidence of chorioamnionitis = admit, steroids, Abx
Define small for gestational age (SGA)
Estimated fetal birth weight (EFW) or abdominal circumference (AC) <10th centime on a customised growth chart
Severe SGA = <3rd centile
Define low birth weight (LBW)
Infant with birth weight <2500g
Define fetal growth restriction
Failure of the ferrous to achieve its predetermined growth potential
Give 5 potential causes of FGR
- Poor nutrition and diet
- Alcohol, smoking, drug use
- Gestational Diabetes
- HTN and preeclampsia
- Placental insufficiency
- Multiple pregnancy
- Structural or chromosomal abnormalities
- Poor weight gain during pregnancy
Briefly describe why FGR often occurs
Trophoblasts don’t invade the placental vessels as normal so respond to vasopressors –> restricting nutrients to baby and restricting growth
What investigations might you so if you are concerned about FGR?
Clinical Examination including SFH
USS –> HC, AC, FL, liquor volume
- Serial scans from 28 weeks if SGA
Umbilical artery doppler
What happens if an umbilical artery doppler is abnormal?
Measure pulsatility index (resistance index)
- Raised –> Monitor
- Intermittent absent –> delivery within 24 hours
- Absent –> Consider stat delivery
- Reversed –> deliver stat
Describe the types of FGR
Symmetrical = head size and AC reduced in parallel Asymmetrical = Abdominal circumference reduced, head circumference normal
Name 2 possible causes of symmetrical FGR
- Congenital/chromosomal abnormalities
- Intrauterine infections
- Environmental factors
Name 2 possible causes of asymmetrical FGR
Often due to later onset pathology
- Pre-eclampsia
- Idiopathic
- Essential HTN
- Smoking
How do you manage early onset FGR (<32 weeks)?
Or symmetric FGR at any gestation
- USS to exclude fetal structural abnormality
- Karyotyping of foetus
- Investigate for viral infection
- Corticosteroids
- Intensive and repeated fetal monitoring
How do you manage late onset FGR (>32 weeks)?
- Corticosteroids
- Increased fetal surveillance
- Possible delivery
Give 2 possible short term complications of FGR
- Premature birth
- Hypoxic brain injury
- Need for respiratory support
Give 2 possible long term complications of FGR
Increased risk of developing
- Coronary heart disease
- HTN
- T2DM
- Hyperlipidaemia
Define large for gestational age (LGA)
Estimated birth weight >90th centile as plotted on customised growth chart
Define fetal macrosomia
Birth weight >4000g
- Often associated with those with diabetic mothers
Briefly describe why macrosomia occurs
Glucose not taken up by mum due to insulin resistance –> excessive glucose in blood –> crosses placenta to baby –> baby takes up excessive amounts of glucose –> stimulates babies’ pancreas to produce higher amount of insulin (anabolic hormone) –> increase in size and build-up of fat
How can is fetal macrosomia managed?
Identification with SFH and USS
Rule out diabetes or treat if present
Plan delivery
Give 3 possible complications of fetal macrosomia
- Shoulder dystocia
- Instrumental delivery
- C section
- PPH
- 3rd degree perineal tears
- Neonatal hypoglycaemia –> need early feeding
Give 2 theories behind the induction of labour
- Placental clock theory –> increased CRH release form placenta –> fetal ACTH please –> release of oestrogen, formation fo myocetrial cap junction –> contractions
- Signals from the baby –> increased ACTh or increase fetal surfactant proteins activate amniotic fluid macrophages –> migrate to uterine wall, upregulartion fo inflammatory gene expression stimulating labour
Give 3 indications for artificial induction of labour
- Post Maturity (T+10)
- Pre-eclampsia
- Diabetes
- Growth restriction
- Reduced fetal movements
- PPROM
- In-utero death
How can labour be induced?
- Membrane sweep (natural induction) –> to see if waters can be broken (in woman at term)
- Balloon catheter –> to help ARM to become possible
- Prostin (prostaglandin E2) pessaries –> cervical priming
- Syntocin can help stimulate contractions once membranes have been ruptured
Give 3 non-pharmacological therapies that can be used to help manage labour pain
- Trained support
- Acupuncture
- Hypnotherapy
- Massage
- Hydrotherapy
Give 3 pharmacological therapies that can be used to help manage labour pain
- Gas and air = entonox
- Paracetamol
- Codeine
- Opioids –> pethidine, diamorphine
- Epidural
- Spinal anaesthesia
Give 2 advantages to entonox
- Rapid onset
- Minimal side effects
- Self limiting
Give 3 potential side effects of opioids
- Sedation
- Respiratory depression
- Nausea and committing
- They cross the placenta (as lipid soluble)
Give 3 indications for an epidural
- Maternal request
- Augmented labour
- Twins
- Existing co-morbidities
What anaesthetic can be given as an epidural?
Bupivacaine
How does bupivacaine work as an epidural?
Blocks sodium channels
Why is an epidural useful if a woman needs to go for an emergency C section?
It can be topped up
Where is spinal anaesthesia injected into and at what level?
The CSF
No higher than L2 or L3 (pudendal nerve S2-4 is main nerve involved in labour)
What is used in a spinal anaesthetic in labour?
Bupivacaine AND fentanyl/diamorphine
Give 3 contraindications for regional anaesthetics (epidural or spinal)
- Maternal refusal
- Local infection
- Allergy
Relative CIs - Hypovolaemia
- Systemic infection
- Coagulopathy/thormbocytopenia
Give 2 advantages of using regional anaesthetic when performing a C-section
- Safer
- Can see baby immediately
- Partner can be present
Give 2 disadvantages of using regional anaesthetic when performing a C-section
- Can cause hypotension
- Can cause headaches
- Patient may experience discomfort from pressure sensations
- Failure
Why would general anaesthetic be given for performing a C-section?
- If there is an imminent threat to mother and/or foetus
- Coagulopathy
- Contraindication of local anaesthetic
- Maternal preference
Name 4 maternal obstetric emergencies
- Antepartum haemorrhage (APH)
- Postpartum haemorrhage (PPH)
- Venous thromboembolism
- Pre-eclampsia
- Amniotic Fluid Embolism
Define antepartum haemorrhage
Bleeding from anywhere in the genital tract after 24 weeks of pregnancy until delivery
Give 3 causes of APH
- Placenta praevia/LLP
- Placenta accreta and placenta percreta
- Placental abruption
- Vasa praevia
- Uterine rupture
Give 3 potential complications of APH
- Premature labour
- Need for blood transfusion
- Actor tubular necrosis (+/- renal failure)
- DIC
- PPH
What is placenta praaevia?
Any part of the placenta that has implanted into the lower segment of the uterus
- Major = covering/reaching the os
- Minor = in lower segment/encroaching
Give 2 risk factors for placenta praevia
- Previous CS
- Smoking
- Assisted reproduction
When might placenta praevia be detected?
20 week anomaly scan = placenta must be <20mm from the cervical os
- It can move repeat scan at 32 (major) or 36 (minor) weeks
What is the classical presentation of placenta praevia?
Intermittent PAINLESS bleeding –> increases in frequency intensity
How is placenta praevia managed?
- If mum is rhesus negative then anti-D
- Steroids if <35+6 weeks
- Placenta >20mm from os for vaginal delivery, <20mm from os = elective C-section at 38 weeks
What is placenta accreta?
Placenta is embedded into the uterine wall
What is placenta percreta?
Placenta is embedded through the uterine wall into the surroundings
Define placental abruption
Premature separation of the placenta from the uterine wall
- Can be concealed or revealed
Give 3 risk factors for placental abruption
- Previous placental abruption
- IUGR
- Preeclampsia
- Smoking, cocaine
- Truma –> RTA, domestic abuse
- Multiple pregnancy
What is the classical presentation of placental abruption?
Sudden onset, constant and severe abdominal pain
Bleeding (but can be concealed)
O/E = tense, woody-hard tender uterus
Fetal distress and maternal shock –> shock doesn’t match blood loss observed
Coagulation failure
How is placental abruption managed?
Fetal CTG, FBC, coagulation screen, cross match, U+Es
Steroids, anti D if rhesus negative, fluids
Urgent C-section if fetal distress
Amniotomy and induction fi >37 weeks
Give 2 potential consequences of placental abruption
- Fetal distres
- Maternal shock –> doesn’t match blood loss observed
- Coagulation failure
What is vasa praevia?
Fetal vessels run through the membranes and below the fetal presenting part
What are the possible consequences of vasa praevia?
Painless and moderate bleeding WHEN MEMBRANES RUPTURE
Can lead led to major fetal haemorrhage
What is the main cause of uterine rupture?
Rupture of caesarean section scar (70%)
Name 2 possible signs of uterine rupture
- Pain and tenderness over the uterus
- Maternal tachycardia
- Sudden maternal shock
- Cessation of contractions
- Disappearance of presenting part from pelvis
How do you manage uterine rupture?
Laparotomy and deliver baby by C-section High flow O2 and IV fluid Small rupture = possible repair Cervix or vagina involved = hysterectomy Abx post surgery
Define primary Postpartum Haemorrhage (PPH)
> 500ml blood loss within 24 hours of delivery
Define Secondary PPH
> 500ml blood loss between 24 hours and 12 weeks post delivery
What is minor PPH?
<1500mls and no lineal signs of shock
What is a major PPH?
> 1500mls and continuing bleeding or clinical shock
What can cause PPH?
The 4 T’s
- Tone –> is the uterus contracted? (atonic uterus)
- Trauma –> tears, episiotomy, rupture
- Tissue –> any retained placental tissue/is the placenta complete?
- Thrombin –> check clotting
Give 5 risk factors for PPH
- Large baby
- Nulliparity and grand multiparty
- Multiple pregnancy
- Precipitate or prolonged labour
- Previous PPH
- Operative delivery
How might you manage a PPH?
Atonic uterus = ergometrine and oxytocin
Retained tissue –> removal of placenta or retained tissue
Laparotomy –> stop bleeding, oversewing or insertion of Rusch ballon, compression, internal iliac or uterine artery ligation, uterine artery embolisation, total/subtotal hysterectomy
Give 5 risk factors for a VTE in pregnancy
- Increasing gestational age
- Obesity (BMI >30)
- Smoking
- C-section
- FHx
- Immobility
- Multiple pregnancy
- Previous VTE
- Thrombophilia
- Medical co-morbidities
- Parity 3 or more
When is a woman at the greatest risk of VTE?
Greatest just after giving birth, postpartum period
What medication can be given to reduce a woman’s risk of VTE?
LMWH (Dalteparin)
TED stockings
When is VTE prophylaxis given?
Antenatally
- From 1st trimester is TRAF >4
- From 28 weeks if TRAF 3
Postnatally
- If antennal prophylaxis = continue for 6 weeks
- 10 days if TRAF >2, 6 weeks if additional risk factors
Describe the pathophysiology of rhesus disease
- Fetal Rh+ RBCs leak through the placenta and interact with the mothers blood –> IgM reaction –> sensitisation
- IgM can’t cross the placenta so there is no RBC lysis but memory B cells are created
- On a subsequent pregnancy, IgG may cross the placenta and cause fetal RBC lysis
What are the potential consequences, if left intreated, of a rhesus negative mother having a rhesus positive fetus?
Risk of RBC lysis –> fetal anaemia and death
What is the only antibody that can cross the placenta?
IgG
How can fetal RBC lysis be prevented in rhesus negative mothers?
Anti-D prophylaxis given
- Destroys Rh+ IgG and so no RBC are attacked
- Given at 28 weeks and 72 hours after sensitising event
Name 3 events during pregnancy when sensitisation of rhesus disease may occur
- Miscarriage
- Abortion
- Amniocentesis
- Placental abruption
- During delivery
When can Anti-D not be used?
If the mum has already produced Anti-D antibodies
What is Amniotic Fluid embolism?
When liquor enters maternal circulation causing anaphylaxis and sudden dyspnoea
Name 3 fetal emergencies
- Fetal distres
- Cord prolapse
- Shoulder dystocia
What is cord prolapse?
When the cord is presenting before the baby after rupturing of the membranes
Give a potential consequence of cord prolapse
Vasospasm –> hypoxia –> fetal morbidity and mortality
Give 4 risk factors for cord prolapse
- Premature ROM
- Polyhydramnios
- Long umbilical cord
- Fetal malpresentaiton
- Multiparity
- Multiple pregnancy
How can cord prolapse be managed?
- Infused fluid into bladder via catheter (elevated presenting part of cord)
- Trendelenburg position (feet higher than head)
- Constant monitoring
- Transfer to theatre for delivery
WHat is shoulder dystocia?
Failure for the anterior shoulder to pass under the symphysis pubis after delivery of the fetal head
Give 3 risk factors for shoulder dystocia
- Macrosomia
- Maternal Diabetes
- Previous shoulder dystocia
- Post maturity
- Prolonged labour
- Obesity
How should should shoulder dystocia be managed?
HELPERR H = call for Help E = evaluate for Episiotomy L = Legs in McRoberts (hyperflexed at hips with thigh abducted and eternal rotated) P = suprapubic Pressure E = Enter pelvis R = Rotational manoeuvres R = Remove posterior arm
Give 3 potential maternal complications of shoulder dystocia
- Vaginal tear
- PPH
- PTSD
- Bladder/uterine rupture
Give 3 potential fetal complications of shoulder dystocia
- Hypoxia
- Cerebral palsy
- Brachial plexus injury (Erb’s palsy)
- Fractured humerus or clavicle
Define puerperium
The period from placental delivery to 6 weeks after birth (postnatal period)
Name 3 features of puerperium
- Return to pre-pregnancy state
- Initiation/suppression fo lactation
- Transition to parenthood
Give 2 endocrine changes that occur during puerperium
- Reduced placental hormones (BhCG, progesterone, oestrogen)
- Increase in prolactin (for lactation)
Give 3 physiological changes that occur during the puerperium
- Involution of the uterus
- Decidua sheds as lochia
- Lactation
Describe the physiology behind the involution fo the uterus in puerperium
There is muscle ischaemia, autolysis and phagocytosis –> involution the uterus
The decider sheds as lochia, what are the 3 stages of the process called?
- Lochia rubra (days 0-4)
- Lochia serosa (days 4-10)
- Lochia alba (days 10-28)
What is the name of the breast milk that is produced at birth?
Colostrum
What does colostrum contain?
- Protein rich
- VItamin A
- NaCl
- Growth factors (stimulate development of infant gut)
- Antibodies (passive immunity)
- Lactoferrin (antimicrobial)
Describe the physiology of lacation
Baby suckles –> sensory impulses from nipple to brain –> prolactin secreted from anterior pituitary –> milk produced my lactocytes –> oxytocin released from posterior pituitary –. my-epithelial contraction –> milk ejection
Name 3 minor things woman are at risk of during puerperium
- Infection
- PPH
- Fatigue
- Anaemia
- Backache
- Haemorrhoids/constipation
