Obs: L&D - onset of labour and premature labour Flashcards
when does labour and delivery normally occur?
between 37 and 42 weeks gestation
define the 3 stages of labour
- *First stage** – from the onset of labour (true contractions) until 10cm cervical dilatation
- *Second stage** – from 10cm cervical dilatation until delivery of the baby
- *Third stage** – from delivery of the baby until delivery of the placenta
what is involve din the first stage and what are the 3 phases of the first stage?
cervical dilation and effacement
‘show’ falls out
latent - from 0 to 3 cm (progress around 0.5cm per hour)
active - 3cm to 7cm (progress around 1cm per hour)
transition - from 7cm to 10cm (progress is around 1cm per hour) strong and regular contractions
what are braxton-hicks contractions?
occasional irregular contractions of the uterus usually felt in the second and third trimester. women can feel temporary and irregular tightening or mild cramping in their abdomen
not true contractions and do not indicate onset of labour
what can help with braxton-hicks?
staying hydrated and relaxing
what are signs of labour?
show
rupture of membranes
regular painful contractions
dilating cervix on examination
what is the latent first stage
when there is both painful contractions and changes to the cervix with effacement and dilation up to 4cm
what is established first stage of labour
when there are both regular, painful contractions and dilation of the cervix from 4cm onwards
define
rupture of membranes (ROM)
spontaneous rupture of membranes (SROM)
prelabour rupture of membranes (PROM)
preterm prelabour rupture of membranes (PPROM)
prlonged rupture of membranes (PROM)
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.
WHO definitions of prematurity
- Under 28 weeks: extreme preterm
- 28 – 32 weeks: very preterm
- 32 – 37 weeks: moderate to late preterm
from what age are babies offered full resuscitation?
24 weeks onwards there is an increased chance of survival and full resuscitation is offered
babies are considered non-viable
23-24 weeks resuscitation not considered in babies that do not show signs of life
describe 2 methods of prophylaxis of preterm labour
vaginal progesterone - vaginal gel or pessary has a role in maintaining pregnancy and preventing labour by decreasing activity of the myometrium and preventing the cervix from remodelling in preparation for delivery. offered to women with cervical length less than 25mm on vaginal ultrasound scan
cervical cerclage - putting a stitch in the cervix to add support and keep it closed and is removed when the women goes into labour or reaches term. offered to women with cervical length less than 25mm on vaginal ultrasound scan between 16 and 20 weeks who have previously had a premature birth or cervical trauma
what is a rescue cervical cerclage?
offered between 16 and 27+6 weeks when there is cervical dilatation without rupture of membranes
how is preterm prelabour rupture of membranes diagnosed?
speculum examination reveals pooling of amniotic fluid in the vagina
where there is any doubt (ie history sounds like pprom but no pooling if fluid seen in the vagina)
- insulin-like growth factor-binding protein-1 (IGFBP-1) present in high concentrations in amniotic fluid which can be testes in vaginal fluid
- placental alpha-microglobin-1 (PAMG-1) similar to IGFBP-1
how is preterm prelabour rupture of membranes managed?
Prophylactic antibiotics to prevent the development of chorioamnionitis. The NICE guidelines (2019) recommend erythromycin 250mg four times daily for ten days, or until labour is established if within ten days.
Induction of labour may be offered from 34 weeks or if signs of chorioamnionitis
what is preterm labour with intact membranes?
regular painful contractions and cervical dilatation without rupture of the amniotic sac
how is preterm labour with intact membranes dianosed?
clinical assessment includes speculum examination to assess for cervical dilation
less than 30 weeks - clinical assessment alone os enough to offer management
more than 30 weeks - transvaginal uss used to assess the cervical length, when less than 15mm management of perterm labour can be offered (more than 15mm = preterm labour unlikely)
fetal fibronectin = alternative to vaginal uss (less than 50ng/ml = negative and indicates preterm labour is unlikely)
how is preterm labour with intact membranes managed
fetal monitoring
tocolysis with nifedipine - CCB that suppresses labour
maternal corticosteroids - offered before 35 weeks gestation to reduce neonatal morbidity and mortality
IV mangnesium sulphate - given before 34 weeks gestation to help protect babys brain
delayed cord clamping or cord milking - increase circulating blood volume and haemoglobin in baby at birth
what is tocolysis?
using medications to stop uterine contractions
Nifedipine 1st line
Atsiban is an oxytocin receptor antagonist used as an alternative when nifedipine is contraindicated
used between 24 and 33+6 weeks gestation in preterm labour to delay delivery and buy time for further fetal development, administration of steroids and transfer to neonatal unit - short term measure 48 hours
what is the significance of giving corticosteroids?
helps to develop the fetal lungs and reduce respiratory distress syndrome after delivery
used in women suspected of preterm labour less than 36 weeks gestation
what is the significance of giving magnesium sulfate?
iv magnesium sulfate to the MOTHER helps to protect the fetal brain during premature delivery, reducing risk and severity of cerebral palsy
given within 24 hours of birth of babies less than 34 weeks gestation
bolus followed by infusion for up to 24 hours after or until birth
close monitoring for magnesium toxicity 4 hourly - obs, tendon reflexes, reduced RR & BP, absent reflexes
