Preterm delivery Flashcards
What is preterm delivery?
Delivery between 24 and 37 weeks gestation.
When are the neonatal risks greater?
Before 34 weeks
How common is preterm delivery?
It occurs In 5-8% of pregnancies. A further 6% of deliveries present preterm contractions but deliver at term
What can cause preterm delivery?
It can be spontaneous labour or, usually at later gestations, can be iatrogenic (PE)
What are some acute neonatal complications of preterm delivery?
NICU, perinatal mortality, cerebral palsy
What are some long-term neonatal complications of preterm delivery?
Chronic lung disease, blindness and minor disability is common.
What are some maternal complications of preterm delivery?
Infection, particularly endometritis. C section is more commonly used.
What are some risk factors for spontaneous preterm labour?
Previous preterm delivery; lower socioeconomic class, extremes of maternal age, short inter-pregnancy interval, maternal medical disease, PE, IUGR, male fetal gender, high Hb, STIs, previous cervical surgery, multiple pregnancy, uterine abnormalities, UTI, congenital fetal abnormalities, antepartum haemorrhage
What are the mechanisms of preterm labour?
In general: [1] too much in the uterus (twins); [2] the foetus wants to get out (IUGR, PE, infection); [3] the uterus can’t hold the baby (uterine abnormalities); [4] the cervix can’t hold it in anymore (cervical incompetence); [5] infection weakens the cervix/uterus (STI, UTI)
How do you investigations predict preterm delivery?
Cervical length of transvaginal sonography (TVS) is both sensitive and specific. Prediction is not the same as prevention though, remember!
How do you prevent preterm labour?
Cervical cerclage (sutures to keep it closed); progesterone supplementation; treatment of polyhydramnios; treat underlying medical conditions
What is cervical cerclage and when is it performed?
The insertion of one or more sutures in the cervix to strengthen it and keep it closed. This is usually prepregnancy and can be laparoscopic.
How does progesterone supplementation take place?
Suppositories from early pregnancy reduce the risk of preterm labour in women at high risk.
What antibiotic increases the risk of preterm labour?
Metronidazole
What are the clinical features of preterm labour?
Typically, women present with painful contractions. In over half of such women, however, contractions will stop spontaneously. Antepartum haemorrhage and fluid loss are common: the latter suggests ruptured membranes
What would you find on examination in preterm labour?
Fever may occur. Check lie and presentation of fetus with abdominal exam. Digital vaginal examination is performed unless the membranes have ruptured. An effaced or dilated cervix confirms the diagnosis
What investigations are performed for preterm delivery?
CTG to assess fetal state; fetal fibronectin (negative result means preterm delivery is unlikely); TVS of cervical length is also predictive; look for infection (CRP and swabs)
How do you manage preterm labour?
Steroids and tocolysis; detection and prevention of infection; mode of delivery
Why are steroids administered in preterm labour?
They reduce perinatal morbidity and mortality by promoting pulmonary maturation
Why are tocolytics administered in preterm labour?
To allow 24hrs for steroids to work or to allow in utero transfer to a unit with neonatal intensive care facilities. They delay rather than stopping preterm labour.
Give two examples of tocolytics that could be administered in preterm labour?
Nifedipine or atosiban
How do you treat chorioamnionitis?
IV antibiotics and immediate delivery, whatever the gestation
Does preterm labour alter the mode of delivery?
No. Vaginal delivery reduces the incidence of respiratory distress syndrome in the neonate and C section is only used for usual obstetric indications
Is breech presentation more common in preterm delivery?
Yes, it usually requires a C section
Should cord clamping be altered in preterm delivery?
Unless immediate neonatal resuscitation is required, the cord should not be clamped for 45 seconds, to reduce neonatal morbidity.
When should antibiotics be given?
They are recommended in women in preterm labour, as opposed to threatening preterm labour, because of the increased risk and morbidity.
What is preterm prelabour rupture of the membranes?
The membranes rupture before labour at <37 weeks.
What are the complications of preterm prelabour rupture of the membranes?
Preterm delivery; infection (chorioamnionitis) or cord (funsitis); prolapse of the umbilical cord; pulmonary hypoplasia
How common is preterm labour after preterm prelabour rupture of the membranes?
It follows within 48 hours in >50% of cases.
Is infection usually before or after the preterm prelabour membrane rupture?
It can occur before (and be the cause of) the rupture or it can follow the rupture
What are the clinical features of preterm prelabour of the membranes?
A gush of clear fluid is normal, followed by further leaking
What would you find on examination after preterm prelabour of the membranes?
A pool of fluid in the posterior fornix on speculum examination is diagnostic, but this is not invariable. Digital examination is best avoided, although it is performed o exclude cord prolapse if the presentation is not cephalic.
What are the clinical features of chorioamnionitis?
Contractions or abdominal pain, fever, tachycardia, uterine tenderness and coloured or offensive liquor, although clinical signs often appear late.
What investigations would you perform in preterm prelabour rupture of the membranes?
US to assess liquor volume; blood tests to look for infection (high vaginal swab, FBC, CRP), CTG to assess fetal well-being
How do you manage preterm prelabour rupture of the membranes?
The woman is admitted and given steroids, close maternal (infection) and fetal surveillance is performed, induction after 36 weeks
Would you give prophylactic antibiotics for preterm prelabour rupture of the membranes?
Erythromycin is usually given prophylactically
What antibiotics would you not give in preterm prelabour rupture of the membranes?
Co-amoxiclav is contra-indicated
