Delivery before term Flashcards
What is preterm delivery? When are neonatal risks considered higher?
Between 24 and 37 weeks gestation. Neonatal risks considered higher at 34 weeks or less.
What are the complications to the neonate of preterm delivery?
Needing neonatal intensive care Perinatal mortality Cerebral palsy Chronic lung disease Blindness Minor disability
What are the likely neonatal outcomes at 24 weeks in comparison to 32?
24 weeks - 1/3 will die, 1/3 will be handicapped.
32 week - <5% die, <5% handicapped
What are the risk factors for spontaneous preterm labour?
History of it Lower socioeconomic class Extremes of maternal age Maternal disease such as renal failure, diabetes, thyroid disease Pre-eclampsia or IUGR Male foetal gender High haemoglobin Vaginal infection Previous cervical surgery Fibroids Multiple pregnancy UTI Antepartum haemorrhage Congenital foetal abnormalities
What are themechanisms causing preterm labour?
Too much inside: twins/triplets, polyhydramnios, excess liquor.
Giving up: foetal survival response - preterm birth is more common where the foetus is at risk such as in pre-eclampsia and IUGR or infection.
Uterine abnormalities: Fibroids or congenital abnormalities.
Cervix is weak: after treatment of CIN, some women have painless cervical dilation
Infection.
What is measured on transvaginal sonography to predict premature delivery?
Cervical length.
What strategies are used to try and prevent preterm labour?
Cervical cerclage - can be elective at 12-14 weeks or when the cervix is seen on US to be shortening.
Progesteron supplementation - suppositories from early pregnancy reduce the risk of preterm labour.
Infection - screening and preventing STIs, UTIs and bacterial vaginosis before 16 weeks is beneficial.
Foetal reduction - reduction of higher order multiples is offered at 10-14 weeks.
Treatment of polyhydramnios by needle aspiration or NSAIDs.
What are the clinical features of preterm labour?
Painful contractions (in over half, contractions will stop spontaneously and labour will not ensue until term).
Dull suprapubic ache or increased discharge (cervical incompetence).
Antipartum haemorrhage and fluid loss.
Dilated cervix confirms diagnosis.
Digital vaginal examination should not be performed if what has happened in preterm labour?
If membranes have ruptured.
What investigations are performed when there are clinical signs of preterm labour?
Assess the likelihood of delivery.
Assess foetal state - CTG and ultrasound.
Look for infection - vaginal swabs should be taken.
What is the management of preterm labour?
Steroids are given between 23 and 34 weeks to reduce perinatal morbidity and mortality by promoting pulmonary maturity.
As steroids take 24 hours to work, the delivery is artificially delayed using tocolysis.
Tocolysis: nifedipine or oxytocin receptor antagonists (e.g. atosiban). Should not be used in the presence of infection.
Detection and prevention of uterine infection with antibiotics as it can kill the mother.
Magnesium sulphate is given <12 hours prior to delivery for neonatal neuroprotection.
Transfer to neonatal intensive care unit.
Delivery: Vaginal reduces incidence of neonatal respiratory distress syndrome, but C-section is undertaken when there are obstetric indication.
What is different about the aims with the membranes in preterm birth?
The membranes are unruptured until 32 weeks gestation to try and cushion the delicate preterm foetus against trauma in birth.
What is preterm prelabour rupture of the membranes?
The membranes rupture before labour at 37 weeks.
What are the complications of prelabour rupture of membranes?
Preterm delivery
Infection (of foetus, placenta or cord is common)
Prolapse of the umbilical cord
Absence of liquor before 22 weeks can result in pulmonary hypoplasia and postural deformities.
What is diagnostic of prelabour rupture of membranes on speculum examination?
Pool of fluid in the posterior fornix.
