Dr.Tarig Mahmoud Ahmed

MD SUDAN

HAIL UNIVERSITY KSA

A pregnancy that has extended to or beyond 42 weeks gestation is defined as a prolonged or post-term pregnancy.

Accurate dating remains essential for the correct diagnosis and ideally involve a first trimester ultrasound estimation of crown–rump length.

Post-term pregnancy affects approximately 10 per

cent of all pregnancies .

Post-term pregnancy increased risk of prolongedlabour and Caesarean section and increased riskof stillbirth and perinatal death (at least two-fold).

post-term pregnancies increased risk of meconium aspiration syndrome (MAS) . Meconium can be aspirated before or after birth.

there are no known tests that can accurately predict fetal

outcome in post-term pregnancy.

Fetal surveillance and induction of labour are two strategies employed that may reduce the risk of adverse outcome.

1. Reduced amniotic fluid on scan.

2. Reduced fetal growth .

3. Reduced fetal movements.

4. CTG is not perfect.

5. Mother is hypertensive.

Immediate indications for induction of labour or delivery

in postdates

Induction of labour is the planned initiation of labour prior to its spontaneous onset.

Approximately one in five deliveries in the UK occur following induction of labour.

Induction of labour

1. Prolonged pregnancy.

2. Fetal growth restriction.

3. Pre-eclampsia and other maternal hypertensive disorders.

4. Deteriorating maternal illnesses.

5. Prelabour rupture of membranes.

6. Unexplained antepartum haemorrhage.

7. Diabetes mellitus.

8. Twin pregnancy continuing beyond 38 weeks.

9. Intrahepatic cholestasis of pregnancy.

10. Maternal iso-immunization against red cell antigens.

11. ‘Social’ reasons.

Common indications for induction of labour

IOL usually recommended between 41 and 42 weeks gestation in Post term pregnancy .

Induction for prolonged pregnancy does not increase the rate of Caesarean section.

At term (beyond 37 weeks),good quality evidence supports IOL approximately 24 hours following membrane rupture (PROM).

Pre-eclampsia at term is normally managed with

IOL, however at very preterm gestations (34 weeks), or where there is rapid deterioration or significant fetal compromise, Caesarean delivery may be a better option.

Maternal diabetes, twin gestation andintrahepatic cholestasis are all common reasonsfor IOL at 38 weeks gestation.

Suspected fetal macrosomia, in the absence ofmaternal diabetes, and isolated oligohydramniosat term are NOT evidence-based indications forIOL.

‘Social’ induction of labour is controversial and is

performed to satisfy the domestic and organizational needs of the woman and her family. It is mostly discouraged, and there must be careful counselling as to the potential risks involved.

placenta praevia .

severe fetal compromise.

Deteriorating maternal condition with major antepartum haemorrhage.

cardiac disease may favour Caesarean delivery.

Breech presentation.

women with a previous history of caesarean birth need to be informed of the greater risk of uterine rupture.

contraindicationsto IOL

High scores (a ‘favourable’ cervix) are associated with an easier, shorter induction that is less likely to fail. Low scores (an ‘unfavourable’ cervix) point to a longer IOL that is more likely to fail and result in Caesarean section.

Bishop score

Score 0 1 2 3

Dilatation of cervix (cm)

0 1 or 2 3 or 4 5 or more

Consistency of cervix

Firm Medium Soft –

Length of cervical

canal (cm)

>2 2–1 1–0.5 <0.5

Position of cervix

Posterior Central Anterior –

Station of presenting

part

-3 -2 -1 or 0 Below spines

Bishop score

ARM and oxytocin:

Oxytocin is given intravenously, as a dilute solution particularly in primiparous .

The starting infusion rate is low and then increase follow every 30 minutes until 3–5 contractions are achieved every 10 minutes.

Methods

Prostaglandin:

Various routes and various preparations have been used.

PGE2, inserted vaginally into the posterior fornix as a tablet or gel. Two doses are often required, given at least 6 hours apart.

A controlled-release pessary is also available and this is left in place for up to 24 hours.

Mifepristone (an anti-progesterone) and misoprostol (another prostaglandin) can be used to induce labour, but complication rates seem higher and this drug combination is currently used in the UK only to induce labour following intrauterine fetal death.

ARM(amniotomy) by hook

Kocher forceps

‘Membrane sweeping’ :

describes the insertion of a gloved finger through the cervix and its rotation against the wall of the uterus.

It releases natural prostaglandins but It can be uncomfortable for the woman.

Greater pain in labour.

Uterine hyperstimulation.

Cord prolapse (ARM + high head).

Greater risk of uterine rupture during VBAC.

Failure.

Increased need for Caesarean or instrumental delivery.

Fetal compromise .

Risks of induction of labour

Thank you