Preterm Delivery Flashcards
Define preterm delivery
Delivery between 24-37wks
What is the incidence of preterm delivery?
5-8% deliver preterm (but a further 6% of deliveries present preterm with contractions but deliver at term)
List the complications for the baby of preterm delivery
- Neurological:
- HIE
- Retinopathy of prematurity
- CP
- IVH - Respiratory:
- RDS
- Chronic lung disease - GI:
- NEC - Haematological:
- Jaundice
- Anaemia - Infection:
- Sepsis
- RTI
- UTI
What guideline is used in cases of preterm delivery?
NICE guideline NG25 Preterm Labour and Birth 2015
List the risk factors for preterm delivery
- Previous history
- Lower SE class
- Extremes of maternal age
- Short-inter pregnancy interval
- Maternal disease e.g. DM, rheumatic fever
- Pregnancy complications - PET, IUGR
- Male fetal gender
- STIs
- Vaginal infection
- Previous cervical surgery
- Multiple pregnancy
- Uterine abnormalities and fibroids, UTI
- Polyhydramnios
- APH
- Congenital fetal abnormalities
How can preterm labour be prevented?
- Cervix = cervical cerclage
- Progesterone supplementation = suppositories from early pregnancy reduce the risk of preterm labour in those who are high risk (disputed efficacy - OPPTIMUM trial)
What is cervical cerclage?
Cervical cerclage is the insertion of one or more sutures in the cervix to strengthen it and keep it closed
What are the different types of cervical cerclage?
- McDonald’s cerclage - placed using permanent suture
- Shiradkor technique
- Abdominal cerclage
When is cervical cerclage used?
- Elective at 12-24wks if high risk
- Cervix scanned regularly and only sutured if significant shortening
- ‘Rescue suture’
What are the indications for prophylactic vaginal progesterone or prophylactic cervical cerclage?
- History of spontaneous pre-term birth or mid-trimester loss between 16+0 and 34+0 weeks of pregnancy
AND
- TVUS carried out between 16+0 and 24+0 weeks of pregnancy revealing a cervical length <25mm
What are the indications for prophylactic vaginal progesterone?
- No history of spontaneous preterm birth or mid-trimester loss in whom TVU has been carried out between 16-24wks showing cervical length <25mm
What are the indications for prophylactic cervical cerclage?
TVUS carried out between 16-24wks revealing cervical length <25mm and who have either of following:
- PPROM in previous pregnancy
- History of cervical trauma
What investigations are carried out to determine if a woman is at risk of preterm delivery?
- Cervical length:
- TVUS
- Sensitive and specific
- If cervical length <15mm at 23wks, 85% chance of delivery before 28wks
List the clinical features of preterm labour
- History:
- Painful contractions
- Dull suprapubic ache - painless cervical dilatation
- APH and SROM - Exam:
- Fever
- Check lie and presentation
- VE = dilatation and effacement
What investigations should be done if preterm labour is suspected?
- Fetal wellbeing:
- CTG
- US - Likelihood of delivery:
- Fetal fibronectin assay (test in swab of secretions from ccervix; negative result [<50ng/ml] = delivery unlikely)
- TVS (cervical length >15mm = delivery unlikely) - Check for infection:
- High vaginal swab (HVS)
- Bloods - WCC, CRP
How do we manage a woman in preterm labour?
- Fetal lung maturity:
- Steroids at 24-37wks - Fetal neuroprotection:
- Magnesium sulphate <32wks (reduces risk of CP)
- HSE CPG 2012 Antenatal Magnesium Sulphate for Fetal Neuroprotection - Tocolysis - can delay delivery up to 7 days in some cases (NOT associated with reduction in mortality or perinatal morbidity - Greentop)
What tocolytic agents can we use in preterm labour?
- Nifedipine - Calcium channel blocker- blocks calcium channels in the myometrium, interrupting contraction
- Atosiban - oxytocin receptor antagonist
What patients benefit from tocolytic treatment?
- Very preterm labour
- Those who need transfer to another hospital
- Allow time for steroids to work
What should be done in the presence of chorioamnionitis?
- IV abx
2. Immediate delivery
Define preterm prelabour rupture of membranes (PPROM)
ROM <37wks
What is the incidence of PPROM?
2% of pregnancies but accounts for 40% of preterm deliveries
List the complications of PPROM
- Preterm delivery - follows within 48hrs in >50%
- Infection - fetus or placenta or cord
- Prolapse of umbilical cord - rare
- Absence of liquor - can result in pulmonary hypoplasia and postural deformities
What is the history like in PPROM?
Gush of clear liquid, followed by further leaking
What will be seen on examination in PPROM?
- Check lie and presentation
- Speculum - pool of fluid in posterior fornix
- VE - best avoided, but can be done to exclude cord prolapse if presentation is not cephalic
- Chorioamnionitis - characterised by contractions or abdominal pain, fever, tachycardia, uterine tenderness and coloured or offensive liquor
