Obs and Gynae Peer Teaching Flashcards
What gestation is normal labour
37 to 42 weeks
Role of prostaglandin in labour
Reduces cervical resistance (cervical ripening) and increased release of oxytocin from posterior pituitary
Role of oxytocin in labour
Stimulates uterine contraction
2 things needed for diagnosis of labour
Painful, regular, progressive uterine contractions
Cervical dilatation and effacement
Describe the latent first phase of labour
Cervix efface and dilate up to 4cm
Describe the active first phase of labour
Progressive cervical dilatation from 4-10cm. Regular painful contractions
Describe the second stage of labour
Full cervical dilatation until birth of baby
Describe the third stage of labour
Delivery of baby to delivery of placenta
How long is latent phase
18hr first, then 12 hour for second baby
What makes you suspect fialure to progress
Less than 2cm dilatation in 2 hours. Arrested descent/ slowing of progress in multips
Causes of abnormal first stage of labour
Inefficient uterine contractions
Cephalopelvic disproportion
Who most commonly gets inefficient uterine contractions in labour and what is the management
Nulliparous.
Amniotomoy and syntocin
Who most commonly gets cephalopelvic disproportion, what are the signs and whats the management
Multiparous women
Caput and moulding are the signs. Secondary arrest (previously good progress).
Do a c section
What counts as a prolonged 2nd stage of labour
2hr of active pushing in nulliparous, 1hr of active pushing in multiparous
What is the management of prolonged 2nd stage
Assisted vaginal delivery or c section
What is a 1st degree tear
Laceration of vaginal epithelium or perineal skin only
What is a 2nd degree tear
Involvement of the perineal muscles but not the sphincter
What is a 3rd degree tear
Disruption of the anal sphincter muscles
What is a 4th degree tear
Disruption of the anal epithelium as well
What is physiological management of 3rd stage
No Syntometrine or syntocin
Cord stops pulsating before clamping
Maternal effort to deliver placenta
When do you change to active 3rd stage of labour management
Haemorrhage or placenta not delivered by 1hr. Reduces risk of PPH
What is the active management of the 3rd stage of labour
IM syntocin
Deferred clamping and cutting of cord
Controlled cord traction
Definition of gestational diabetes
Carbohydrate intolerance which is diagnosed in pregnancy
Why does gestational diabetes happen
Reduced glucose tolerance due to change in carbohydrate metabolism
Antagonistic effect of human placental lactogen, progesterone and cortisol
Risk factors for gestational diabetes
Maternal obesity (BMI>30)
Previous macrosomic baby
Previosu GDM
1st degree relative with DM
Effects of pregnancy on diabetes
Increased DKA and hypo risk
Increased retinopathy and nephropathy risk
Effects of diabetes on pregnancy anagram
SMASH
SMASH anagram of diabetes effects on pregnancy
Shoulder dystocia Macrosomnia Amniotic fluid excess Still birth HTN, Hypoglycaemia
What can shoulder dystocia cause
Erbs palsy
Which circumference is bigger in a GDM baby
AC bigger than HC on USS
What is the name for amniotic fluid excess
Polyhydramnios
Why will a GDM baby get hypoglycaemia
Hyperinsulinaemia
How do you diagnose GDM
Oral glucose tolerance test
2hr, 75g oral glucose
Done at booking then repeated at 24-28 weeks if normal
What is the threshold for OGTT and Fasting glucose of GDM
- 8mmol/L OGTT
5. 6mmol/L Fastin
Counselling for mums who are already diabetic
Achieve optimal control
Screen complications
Alter meds
Folic Acid
What medications need to be stopped in pregnancy
ACEis, Statins, all other hypoglycaemics
Why does folic acid need to be given especially to GDM mums
Increased risk of neural tube defects
Steps of GDM treatment
Diet/exercise
Metformin
Insulin
Glibenclamide
Fetal monitoring for GDM
Serial USS (size and amnio) Fetal echo at 20-24wks (CHD)
GDM labour
Delivery before 41wks
Induce by 39
Vaginal delivery and continued monitoring preferred
If >4kg then elective CS
IV dextrose and sliding scale insulin given
Post birth GDM advice baby
Breastfeeding
Monitor fetal BG as risk of hypoglycaemia
Post partum GDM advice mum
Stop insulin and arrange OGTT at 6 weeks postpartum
What is rhesus disease
Maternal antibody response mounted against fetal red cells
What combination of rhesus parents leads to rhesus disease
Rhesus negative mum, rhesus positive dad
How does sensitisation work in rhesus disease work
During first pregnancy, fetal blood crosses into maternal circulation. Maternal immune response to Rh D+ve antigens on foetal RBCs
Why isnt the first rhesus pregnancy at risk
Initially IgM can not cross the placenta
How does rhesus disease happen in the second pregnancy
Memory B cells produce rapid immune response (IgG) which crosses into the foetal circulation causing haemolytic anaemia (foetal hydrops if severe
Sensitising events for rhesus
surgery after miscarriage Ectopic pregnancy Blunt abdo trauma Amniocentesis Intrauterine death Delivery
Management of rhesus disease
All mums checked at booking visit, 28 and 34 weeks.
How do you assess and treat fetal anaemia
MCA doppler (increased flow velocity) Prevention= antiD immunoglobulin Kleihauer test
What is kleihauer test
Tests for foetal maternal haemorrhage
Define chronic hypertension (obs and gynae)
HTN before pregnancy (also includes HTN before 20 weeks)
Define pregnancy induced hypertension
Gestational non proteinuric HTN
New persistent hypertension after 20 weeks gestation without evidence of preeclampsia
Threshold of hypertension in pregnancy
140/90
Define preeclampsia
HTN and proteinurina, specific to pregnancy and puerperium
Preeclampsia risk factors acronym
NOPE 2 FAT
NOPE 2 FAT preeclampsia risk factors
Nulliparity
Obesity
Previous Hx
Extremes of age
2- twins
Family History
Autoimmune (anitphospholipids)
Twins
Pathophysiology of preeclampsia
Failure of trophoblastic endovascular remodelling. Spiral arteries remain high resistance (coil and not dilated). Causes placental ischaemia
Presentation of preeclampsia
Most asymptomatic.
Headache, visual disturbances, epigastric/ RUQ pain.
Nausea and vomitting
Rapid oedema (esp. face)
Preeclampsia on examination
Hypertension Proteinuria Facial oedema Epigastric/ RUQ pain Brisk hyperreflexia/ ankle clonus
Preeclampsia kidney complications
Reduced renal blood flow and GFR
Increased uric acid/ urea/ creatinine and proteinuria
Preeclampsia liver complications
HELLP syndrome
Coagulation system changes
What is HELLP syndrome
Happens to the liver in preeclampsia (haemolysis, high ALT, high AST, low platelets)
What haemolytic changes happen to the liver in preeclampsia
Thrombocytopenia, Low antithrombin III, increased fibronectin
What is eclampsia
Generalised tonic clonic seizures
What CNS changes happen in preeclampsia
Eclampsia
Headaches
Visual disturbances
Severe complications of preeclampsia
Eclampsia HELLP Stroke Renal failure Placental abruption
Foetal complications of preeclampsia
IUGR (placental insufficiency)
Preterm
Oligohydramnios
IUFD
Preeclampsia diagnosis
New persistent raised BP (>140/90 at 20+ weeks) AND Proteinuria 300mg+ in 24hr collection or 2+ on dipstick
Mild and moderate preeclampsia classification
BP less than 160/110 with significant proteinuria and no complications
Severe preeclampsia classification
BP >160/110
Proteinuria over 1g/24hr or 2++
Maternal complications occur
What is the only cure of preeclampsia
Delivery of placenta
Preferred delivery route for preeclampsia
Induction of labour and vaginal
If pregnancy at risk which drug do you give from 12 weeks in preeclampsia
Low dose aspirin
Which drug do you give if preeclampsia is moderate/severe at 34 weeks
Steroids- bethametasone
Which drug do you give to treat eclampsia but then must deliver
IV Magnesium Sulphate
Which drug is used to treat acute severe preeclampsia and what do you give if asthmatic or CHF
PO Labetalol (methyldopa if asthmatic/CHF)
What is the definition of antepartum haemorrhage
Bleeding from genital tract after 24 weeks gestation and prior to the onset of labour
How much is minor APH
Less than 50mL
How much is major APH
50-1000mL
How much is massive APH
> 1000mL and or signs of shock
Uterine differentials of APH
Placental abruption
Placenta praevia, vasa praevia
Cervical differentials of APH
Show (loss of mucus plug)
Cervical cancer/ polyps
Cervical ectropian
Vaginal differentials of APH
Trauma
Infection
Velamentuous placenta
Umbilical vessels go within the membranes before placental insertion
Placenta accreta
chorionic villi attach to the myometrium, rather than being restricted within the decidua basalis.
Placenta increta
chorionic villi invade into the myometrium.
Placenta percreta
chorionic villi invade through the perimetrium
Risk factors for placenta accreta
Previous accreta
C-section
uterine surgery
Investigations for placenta crreta
Ultrasound scan (MRI can complement)
Management for placenta accreta
Aim to deliver in 35th week.
C section hysteretomy with placenta in situ
Uterine preserving surgery
Placenta praevia definition
Implantation of placenta, wholly or in part, in the lower segment of the uterus
What happens to 90% of low lying placentas at 20 weeks
Resolve as the pregnancy progresses and lower uterine segment grows
Risk factors for placenta praevia
Multiparity, smoking, mulitple pregnancy, advanced age, previous PP, previous c section
Define marginal placenta praevia
Placenta in lower segment of uterus, close to the internal OS
Define major placenta praevia
Placenta lies over the OS (cervical effacement and dilatation= catastrophic bleeding)
placenta praevia symptoms
Intermittent painless bright red bleeds, which increase in frequence and severity over the weeks
Placenta praevia on physical examination
Soft uterus
Foetal malpresentation
Foetal head not engaged and high
Investigations of placenta praevia
Diagnostic USS if low lying at 2nd trimester, repat at 32.
Management of placenta praevia
Avoid sex, dont do a vaginal examination. If previously bled and major, monitor till delivery.
Elective C section 37-39wks.
Single steroid course at 35 weeks
Placenta abruption definition
Premature seperation of a normally sited placenta from the uterine side wall
Whats the difference between a revealed abruption and a concealed abruption
Revealed has visible bleeding, concealed doesnt
Risk factors for placenta abruption
Previous abruption Preeclampsia IUGR Abnormal placentation Rapid uterine decompression
Symptoms of placenta abruption
Abdominal pain and bleeding. Sudden onset severe constant bleeding. Contraction leads to blood clot which irritates and promotes contraction
Placental abruption on examination
Tender, contracting WOODY HARD uterus. Maternal shock and foetal distress
Investigations for placental abruption
Diagnosis on clinical grounds. Foetal CTG, USS, Maternal FBC, clotting, Xmatch, U+E
Management of placental abruption
Immediate delivery
Usually CS and resus simultaneously