99. labour Flashcards
Stages of labour?
Latent phase: irregular contractions, mucous plug, cervix beginning to efface up to 4cm
First stage: strong regular uterine contractions, cervical dilatation up to 10cm
Second stage: from full dilation to delivery of baby
Third stage: from birth of baby to expulsion of placenta
Define labour
regular painful contractions with cervical changes
mechnism of labour
Descent
Flexion
Internal rotation
Extension
Restitution
External rotation
Delivery of body
cardinal movements of labour
Descent
Flexion
Internal rotation
Extension
Restitution
External rotation
Delivery of body
Ideal foetal position
occiput anterior
left occiput anterior is ideal
entonox
gas and air
Gas and air contains a mixture of 50% nitrous oxide and 50% oxygen. This is used during contractions for short term pain relief.
IM diamorphine vs IM pethidine
Pethidine shorter
Diamorphine longer and more powerful
Braxton-Hicks Contractions
occasional irregular contractions of the uterus. They are usually felt during the second and third trimester.
Diagnosing labour
Show (mucus plug from the cervix) clear or bloody show
Rupture of membranes
Regular, painful contractions
Dilating cervix on examination
Active management of the third stage
intramuscular oxytocin
Rupture of membranes (ROM)
The amniotic sac has ruptured.
Spontaneous rupture of membranes (SROM)
The amniotic sac has ruptured spontaneously
Prelabour rupture of membranes (PROM)
The amniotic sac has ruptured before the onset of labour.
Preterm prelabour rupture of membranes (P‑PROM)
The amniotic sac has ruptured before the onset of labour and before 37 weeks gestation (preterm).
Prolonged rupture of membranes (also PROM)
The amniotic sac ruptures more than 18 hours before delivery.
cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation
vaginal progesterone to maintain pregnancy
cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had a previous premature birth or cervical trauma (e.g. colposcopy and cone biopsy)
Cervical cerclage
Complications of PPROM
fetal: prematurity, infection, pulmonary hypoplasia
maternal: chorioamnionitis
Investigation PPROM (premature, prelabour)
A sterile speculum examination should be performed (to look for pooling of amniotic fluid in the posterior vaginal vault)
but digital examination should be avoided due to the risk of infection.
Ultrasound may also be useful to show oligohydramnios.
Management PPROM prolonged
- admission
- regular observations to ensure chorioamnionitis is not developing
- oral erythromycin should be given for 10 days 250mg four times daily
- antenatal corticosteroids should be administered to reduce the risk of respiratory distress syndrome
- delivery should be considered at 34 weeks of gestation - there is a trade-off between increased risk of maternal chorioamnionitis with a decreased risk of respiratory distress syndrome as the pregnancy progresses
Preterm labour with intact membranes
regular painful contraction and cervical dilatation, without rupture of the amniotic sac.
Tests if diagnostic doubt about PPROM premature prelabour
Insulin-like growth factor-binding protein-1 (IGFBP-1)
Diagnosis of preterm labour with intact membranes
Less than 30 weeks gestation, clinical assessment alone is enough to offer management of preterm labour.
More than 30 weeks gestation, a transvaginal ultrasound can be used to assess the cervical length. When the cervical length on ultrasound is less than 15mm, management of preterm labour can be offered. A cervical length of more than 15mm indicates preterm labour is unlikely.
Tocolysis
involves using medications to stop uterine contractions. Nifedipine, a calcium channel blocker, is the medication of choice for tocolysis. Atosiban is an oxytocin receptor antagonist that can be used as an alternative when nifedipine is contraindicated.