Obs: L&D - onset of labour and premature labour

Question 1

when does labour and delivery normally occur?

Answer 1

between 37 and 42 weeks gestation

Question 2

define the 3 stages of labour

Answer 2

• *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

Question 3

what is involve din the first stage and what are the 3 phases of the first stage?

Answer 3

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

Question 4

what are braxton-hicks contractions?

Answer 4

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

Question 5

what can help with braxton-hicks?

Answer 5

staying hydrated and relaxing

Question 6

what are signs of labour?

Answer 6

show

rupture of membranes

regular painful contractions

dilating cervix on examination

Question 7

what is the latent first stage

Answer 7

when there is both painful contractions and changes to the cervix with effacement and dilation up to 4cm

Question 8

what is established first stage of labour

Answer 8

when there are both regular, painful contractions and dilation of the cervix from 4cm onwards

Question 9

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)

Answer 9

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.

Question 10

WHO definitions of prematurity

Answer 10

• Under 28 weeks: extreme preterm
• 28 – 32 weeks: very preterm
• 32 – 37 weeks: moderate to late preterm

Question 11

from what age are babies offered full resuscitation?

Answer 11

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

Question 12

describe 2 methods of prophylaxis of preterm labour

Answer 12

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

Question 13

what is a rescue cervical cerclage?

Answer 13

offered between 16 and 27+6 weeks when there is cervical dilatation without rupture of membranes

Question 14

how is preterm prelabour rupture of membranes diagnosed?

Answer 14

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

Question 15

how is preterm prelabour rupture of membranes managed?

Answer 15

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

Question 16

what is preterm labour with intact membranes?

Answer 16

regular painful contractions and cervical dilatation without rupture of the amniotic sac

Question 17

how is preterm labour with intact membranes dianosed?

Answer 17

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)

Question 18

how is preterm labour with intact membranes managed

Answer 18

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

Question 19

what is tocolysis?

Answer 19

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

Question 20

what is the significance of giving corticosteroids?

Answer 20

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

Question 21

what is the significance of giving magnesium sulfate?

Answer 21

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