Fetal medicine Flashcards
What is Pre-Term-Labor (PTL)?
PTL is labour that occurs before 37 weeks’ gestation
What is threatened labor ?
It is labor that occurs prior to 24 weeks.
PTL ultimately ending with preterm birth (PTB) accounts for the majority of _______in normally-formed infants
perinatal morbidity
What are the causes for Iartogenic PTB?
Pre-eclampsia
Intrauterine Growth Restriction (IUGR)
Maternal disease necessitating delivery
What are the spontaneous causes of PTB?
Preterm labour (PTL)
Preterm premature rupture of the membranes (PPROM)
Cervical incompetence
What are the non- pregnancy related risk factors for PTB?
Low socio-economic group
Extremes of age
Poor nutritional status
Smoking
Drug abuse
What are the pregnancy related risk factors for PTB?
Multiple pregnancy
PPROM
Uterine anomalies
History of preterm delivery in prior pregnancy
Placenta praevia
Placental abruption
Polyhydramnios
Medical complications of pregnancy e.g. PET
Intrauterine infection
What is the marker of PTB between 23-35 weeks of gestation?
Positive Fetal Fibronectin in cervicovaginal swab. It has high negative predictive value as its absence suggest <1% chance or PTB.
What is the relationship b/w cervix length and PTB?
The shorter the cervix the higher the risk of PTB which can be measured through transvaginal US.
Short cervix _____ predicts 75% cases PTB
(<25mm)
Weekly IM injections of ______reduced incidence of recurrent PTB by 1/3 in patients with prior PTB
17α-hydroxyprogesterone caproate
What is the indication for cervical Cerclage in high risk cases for PTB?
*Short cervix found on transvaginal ultrasound <20 weeks
*Prior early PTB
*Cervical incompetence (silent dilation of cervix leading to prior pregnancy loss <20 weeks)
What are the clinical indications of PTL ?
Regular painful contractions <37 weeks+ Cervical change+ Cervical dilation.
What are the management options in PTL ?
- Administer antenatal corticosteroids (Dexamethasone 6mg 12 hourly x 4 doses)
- Tocolysis
- MgSO4 if delivery imminent <32 wks
- Transfer to tertiary level NICU
Antenatal Corticosteroids should be administered between ______ in any case of anticipated preterm birth (e.g. threatened preterm labour)
24 and 37 weeks
What are the benefits of corticosteroids in PTL?
*Reduction in neonatal mortality
*Reduction in Respiratory Distress Syndrome.
*Reduction in Intraventricular Haemorrhage.
*Reduction in Necrotising Enterocolitis.
*Benefit occurs after 24 hours, and lasts up to 7 days
What are tocolytics and their efficacy in PTL ?
These are agents that stop contractions and their effectiveness in PTL is controversial.
What are the common tocolytics used in PTL?
*Atosiban: oxytocin receptor antagonist (IV)
*Nifedipine: calcium channel blocker (oral)
*Ritodrine or Terbutaline: beta adrenergic agonist (IV)
*Magnesium Sulphate: competitive antagonist to calcium (IV)
*Indomethacin: interferes with prostaglandin synthesis (PR)
What is the Role of magnesium sulphate in PTL ?
- MgSO4 has proven neuroprotective effect (NMDA antagonist)
- RCTs prove 30% to 40% reduction in cerebral palsy
*
How is MgSO4 administered in suspected PTL ?
*Give IV Infusion MgSO4 (4g bolus / 2g per hr maintenance) immediately prior to anticipated preterm birth 24-32 wks
What are the indications for MgSO4?
*Labour < 32 wks (>5cm dilated)
*Severe Preeclampsia being delivered < 32 wks
*Severe IUGR being delivered <32 wks
What antibotics Should be administered to all patients with threatened preterm labour prior to 37 weeks’ gestation?
3g Benzylpenicillin IV followed by 1.8g 6-hourly (Clindamycin if penicillin allergic)
What is the prophylaxis for early onset neonatal Group B Streptococcal meningitis?
penicillin
What are the neonatal consequences of pre-term birth?
*Respiratory distress syndrome (RDS)
*Necrotising enterocolitis (NEC)
*Intraventricular haemorrhage (IVH)
*Periventricular leukomalacia (PVL)
*Sepsis
Patent ductus arteriosus (PDA)
Intellectual impairment / Cerebral palsy and Death
What is Preterm Premature Rupture of the Membranes ?
rupture of membranes before 37 wks gestation
Preterm PROM (PPROM) is ___
ROM <37 weeks.
Prolonged ROM refers to _____
ROM > 24hrs
What are the risk factors for PPROM?
*Spontaneous / Idiopathic (most cases)
*Infection: Chlamydia, GBS,
*Smoking
*Placental abruption
*PPROM in prior pregnancy
*Incompetent Cervix
*Multiple Pregnancy (twins / triplets)
*Polyhydramnios
Iatrogenic (after amniocentesis)
What is the test with high specificity and sensitivity for diagnosing PPROM ?
Placental alpha-macroglobulin-1
What are the Goals of PPROM Management?
*Prolonging gestation for as long as it is safe to do so.
*Monitoring for signs of intrauterine infection
*Promoting lung maturity by administering antenatal corticosteroids
*Optimizing the time and mode of delivery
What are the signs of maternal infection in PPROM?
*Foul smelling vaginal fluid
*Contractions / preterm labour
*Pyrexia (>38oC)
*Tachycardia (>100bpm)
*Uterine tenderness
*Raised white cell count / c-reactive protein
What are the PPROM surveillance factors ?
*Maternal signs of infection
*Fetal signs of infection
*Serum markers of infection
*Ultrasound markers of fetal compromise
*Altered biophysical profile (BPP)
CTG abnormalities
What are the signs of fetal infection in PPROM?
*Fetal tachycardia (>160bpm)
*Non-reactive / reduced variability on CTG
*Alteration in biophysical profile
-Loss of breathing movements
-Decrease in gross body movements
What is the management of PPROM?
*Admit when viability reached (24 wks)
*Close maternal and fetal surveillance, with at least daily CTG tracing
*Steroids – Dexamethasone x2 over 24 hrs
*Antibiotics - Erythromycin 250mg PO QDS x 10 days prolongs latency until delivery
*MgSO4 – IV infusion if delivery imminent and <32 wks
All cases of PPROM should be delivered by __ wks, as there is no benefit to continuing pregnancy beyond this time, while there is considerable risk
37
What is midterm PPROM?
It is rare and occurs between 16 to 24 weeks. It has poor overall prognosis. If there is no infection the survival is 50 to 75% overall.
Pulmonary hypoplasia is major complication if _____ present at 18-22 wks
anhydramnios and consider pregnancy termination due to high risk of materal infection.
