obsteterics Flashcards
Effacement
Starts in the fundus (pacemaker)
Retraction/shortening of muscle fibres in cervix, that build in amplitude as labour progresses
Fetus forced down-pressure on cervix
effacement leads to …
dilation
fully dilated at 10cm
mechanical factors that affect active labour 3ps
Powers - the degree of force expelling the fetus
primigravida women and induced = poor uterine contractions
Passage
Bony pelvis - inlet, mid cavity, outlet
Ischia spine - used to assess decent (station)
Soft tissues - cervical dilation, vagina and perineum need to be overcome in second stage
macrosomnia, inadequate pelivs (to small)
Passenger - the diameters of the fetal head
malpresentation (breach)
pan relief in labour - opiates
examples
fetal SE
Pethidine/morphine
Side effects Fetal
Respiratory depression
Diminishes breast-seeking, breast-feeding behaviours
pan relief in labour - opiates
examples
maternal SE
Pethidine/morphine
Side effects-maternal
Euphoria & dysphoria
Nausea/vomiting
Longer 1st and 2nd stage labour
epidural maternal SE
Side effects-maternal Increase length 1st & 2nd stage Need for more oxytocin (synctocinon) Increase incidence malpositon Increase instrumental rate
epidural fetal SE
Tachycardia due to maternal temp
Diminishes breast feeding behaviours
1st stage of labour - latent phase
painful, irregular contractions
cervix effaces - becomes shorter and softer
then dilates to 4cm
1st stage of labour - establishment phase
regular contractions
dilation from 4cm increasing 0.5cm/h
asses contractions strength, frequency every 30mins
asses maternal BP temp and pulse
2nd stage of labour - passive stage
complete cervical dilation (10cm)
until head reaches pelvic floor and desire to push experienced (but no pushing)
completes rotation and flexion. Lasts a few mins.
2nd stage of labour - active stage
Regular, frequent contractions
Progressive
Role of oxytocin
mechanism of labour / passage of fetus through birth canal (8)
Engagement - head enters pelvis in occipito-transverse (OT) position.
Descent and flexion - head descends and flexes as the cervix dilates.
Internal Rotation - head internally rotates 90 degrees, baby in OA position (all during early 2nd stage)
Rotation complete, further descent
Crowning - perineum distends
Extension and delivery
Restitution - head rotates 90 degrees to the same position in which it entered the pelvis to enable delivery of the shoulders (aligns its head with the shoulders)
Internal rotation - shoulders rotation from a transverse position to an anterior-posterior position
lateral flexion
3rd stage of labour
delivery of placenta
Check placenta and membranes complete
delayed cord clamping - improves iron status and reduces prevalence of neonatal anaemia
active - oxytocin by IM injection to reduce the risk of PPH
low birth weight values
<2500gm at birth regardless of GA
LBW: <2500gm
VLBW: <1500gm
ELBW: <1000gm
prematurity risk factors
anterpartum haemorrhage unkown multiple pregnancys chorioamnionitis anaemia (iron def)
primary prevention of pre term birth
Reducing population risk Effective interventions not demonstrable yet Smoking and STD prevention Prevention of multiple pregnancy Planned pregnancy Variable work schedules Physical and sexual activity advice Cervical assessment at 20-26 weeks
diagnosis of labour
Persistent uterine activity / contractions AND change in cervical dilatation and/or effacement
screening of pre term labour
Transvaginal cervical ultrasound - cervical length
fetal fibronectin
Extracellular matrix protein found in choriodecidual interface. Abnormal finding in cervicovaginal fluid after 20 wks may indicate disruption of attachment of membranes to decidua
management of pre term labour
corticosteroids (betamethosone) - for fetal surfactant production, close patent ductus
nifedipine can suppress labour, allows time for surfactant to work
magnesium sulfate - neuroprotective
chronic hypertension definition
Hypertension diagnosed
Before pregnancy
Before the 20th week of gestation
During pregnancy and not resolved postpartum
Gestational Hypertension definition
New HT after 20 wks gestation Systolic >140 Diastolic>90 No or little proteinuria 25% develop pre-eclampsia
pre-eclampsia definition
hypertension and proteinuria in pregnancy
New HT after 20th week (earlier with trophoblastic disease)
eclampsia definition
pre-eclampsia and tonic clonic seizures
pre-eclampsia diagnosis
Gestational Hypertension Systolic >140 Diastolic>90 Proteinuria ≥ 0.3g protein /24hr ≥ +2 on urine dip specimen sudden weight gain odema
severe pre-eclampsia clinical features
BP: >160 systolic, >110 diastolic
Proteinuria: >5gm in 24 hrs, over 3+ urine dip
Oliguria: < 400ml in 24 hrs
CNS: Visual changes, headache, scotomata, mental status change
Pulmonary Edema
Epigastric or RUQ Pain
Preeclampsia Superimposed Upon Chronic Hypertension clinical features
A. HT and no proteinuria < 20 wks: New-onset proteinuria after 20 weeks B. HT and proteinuria < 20 weeks: Sudden increase in proteinuria Sudden increase in BP when HT was well controlled Thrombocytopenia (<100,000) Abnormal ALT/AST
symptoms of pre-eclampsia
Visual disturbances. Headache similar to migraine. RUQ/Epigastric pain - hepatic swelling and inflammation, stretch of liver capsule ± Oedema Rapid weight gain ankle clonus
management of severe pre-eclampsia
labetalol
nifedipine - antihypertensive, use with caution
corticosteroids and magnesium sulfate (to prevent seizures) - caution renal failure
delivery the only cure
low dose aspirin for any pregnancy with RF
maternal indications for delivery in pre-eclampsia
Gestational age 38 wks
Platelet count < 100,000 cells/mm3
Progressive deterioration in liver and renal function
Suspected abruptio placentae
Persistent severe headaches, visual changes, nausea, epigastric pain, or vomiting
Delivery should be based on maternal and fetal conditions as well as gestational age.
fetal indications for delivery in pre-eclampsia
Severe fetal growth restriction (IUGR)
Nonreassuring fetal testing results
Oligohydramnios
Delivery should be based on maternal and fetal conditions as well as gestational age.
HELLP syndrome predisposing cause and features
pre-eclampsia
haemolysis
elevated liver enzymes
low platelets
delivery only ‘cure’
Puerperium definition
From the delivery of the placenta to six weeks following the birth
lochia rubra features
day 0-4 dark red
Blood Cervical discharge Decidua Fetal membrane Vernix Meconium
lochia serosa features
day 4-10 pinkish brown
Cervical mucus Exudate Fetal membrane Micro-organisms White blood cells
lochia alba features
day 10-28 whitish yellow
Cholesterol Epithelial cells Fat Micro-organisms Mucus Leukocytes
Colostrum
first form of milk produced by the mammary glands
rich in proteins, vitamin A, and sodium chloride
contains lower amounts of carbohydrates, lipids, and potassium than mature milk.
provides passive immunity (antimicrobial factors), stimulates the development of the infant gut (growth factors)
endocrine changes during Puerperium
decrease in serum levels of placental hormones (human placental lactogen, hcg, oestrogen and progresterone)
Increase of prolactin
sepsis - 3Ts with sugar
Temperature <36 or >38 degrees Tachycardia -Heart rate > 90bpm (PN) Tachypnoea - Respiratory rate > 20bpm WCC >12 or <4 x 109/l Hyperglycaemia >7.7mmol
postpartum haemorrhage definition (minor and major) and causes (primary)
loss >500ml blood in first 24hrs after delivery
Minor PPH Estimated Blood Loss < 1500mls and no clinical signs of shock.
Major PPH Estimated Blood loss of 1500mls or more and continuing to bleed OR clinical shock
tone - uterine atony (muscle has lost its strength)
tissue - retained products of conception
trauma - genital tract trauma
thrombin - clotting disorders
postpartum haemorrhage secondary
Abnormal or excessive bleeding from birth canal between 24hrs and 12 weeks postnatally
normally caused by retained placental tissue
venous thromboembolism high risk factors and management
investigations
previous VTE
treatment for antenatal LMWH
high risk thrombophilia
low risk thrombophilia and fam Hx
LMWH (dalteparin) thromboprophylaxis should be given to anyone with risk factors 6 weeks post partum
NOACs contraindicated in pregnancy
ventilation/perfusion scan
d dimer
VTE signs and symptoms
DVT - leg swelling, pain, tenderness
PE - SoB, chest pain, haemoptysis
VTE treatment
LMWH - dalteparin (parin) (stop during labour)
baby blues
a brief period of feeling emotional and tearful around three to 10 days after giving birth
