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
