بسم الله الرحمن الرحيم

بسم الله الرحمن الرحيم

Prostaglandin E2 (PGE2) (Dinoprostone) • -Prostaglandins are naturally occurring female hormones present in tissues throughout the body. • Prostaglandin E2 and F2 are known to be produced by tissues of the cervix, uterus, deciduas and the fetal membranes and to act locally on these structures. • Dinoprostone is the active ingredient in PGE2 vaginal tablets, gel and pessaries It replicates prostaglandin E2 produced by the uterus in early labour to ripen the cervix and is seen as a more natural method than the use of oxytocin.

PGE2 placed high in the posterior fornix of the vagina, taking great care to avoid inserting it into the cervical canal is absorbed by the epithelium of the vagina and cervix leading to relaxation and dilatation of the muscle of the cervix and subsequent contraction of uterine muscle.

According to the use of a prostaglandin greatly increases the probability of delivery occurring within 24 hours, and prior to the use of oxytocin potentiates the effects of the oxytocic agent

Insertion of prostaglandins. The posterior fornix of the vagina is used to insert prostaglandins for ripening or induction of labor. The key point is that when undertaking a vaginal examination to assess the cervix midwives should follow the direction of the vagina, which will be directed posterior if the woman is semi-recumbent. The uterus is anteverted and anteflexed, creating the posterior fornix.

-the use of gel, tablet or controlled release pessary. • the women receiving the slow release pessary gave a higher satisfaction score with regards to their perception of labor.

the diﬀerence in cost between the gel, tablet and controlled release pessary, with currently the later being : • more expensive

Prior to the insertion of PGE2, the midwife will carry out an abdominal examination to • conﬁrm fetal lie, presentation, descent of presenting part and fetal wellbeing by use of electronic fetal monitoring (EFM).

All ﬁndings are clearly recorded in the woman's maternity records • Following insertion of PGE2 the woman is advised to lie down for 30 minutes. When contractions begin continuous EFM is used to assess fetal wellbeing.

If the CTG is conﬁrmed to be normal, i.e. all four features are considered to be reassuring, the CTG can be discontinued and intermittent auscultation used Currently the IOL process commonly takes place as an inpatient, either on the antenatal ward or labor suite depending on the reason for IOL.

starting the IOL process in the morning rather than the evening • Prior to the administration of the PGE2 the midwife must conﬁrm there is a bed available on the labor suite in the event there is a need to transfer the woman as a matter of urgency.

If there are any maternal or fetal risk factors in the pregnancy the IOL must take place on the labor suite.

-Where the membranes are intact or ruptured the recommended initial dose for all women, whether it is a ﬁrst or subsequent pregnancy, is one dose of PGE 2 tablet (3 mg) or gel (1–2 mg), • re-assess in 6 hours and if labor is not established, and the woman has given consent,

a second dose of tablet or gel is inserted into the posterior fornix of the vagina. • one cycle of PGE2 controlled-release pessary (10 mg) can be given over 24 hours, which is one pessary.

The maximum recommended dose of PGE2 tablet, gel or controlled-release pessary being one cycle . • Side- eﬀects of PGE2 include nausea, vomiting and diarrhea • If labor is not established after one cycle of treatment the IOL is classed as having failed,

both mother and baby are in good health discussion must take place between the woman and doctor with regards to further options – these being another attempt to induce labour or elective caesarean section

Vaginal PGE 2 is currently the only recommended route for the use of prostaglandins for IOL. • Misoprostol (PGE1) is not licensed for use • Whilst it is thought to be more eﬀective and less expensive than PGE2 and oxytocin for the IOL there remain questions about safety issues with regards to uterine hyper stimulation. • PGE1 is recommended for IOL only where there is an intrauterine fetal death (IUFD).

With a caesarean section (CS) ,more women with a uterine scar will be faced with the decision regarding IOL. • women with a previous lower segment caesarean section (LSCS) may now be oﬀered IOL using PGE2. It is important for the midwife to understand the signiﬁcance of a scarred uterus

and choices with regards to IOL to ensure the woman is informed of the increased risk of requiring an emergency CS and increased risk of rupture of the uterus.

Risk associated with use of PGE2 • -The use of PGE2 can be unpredictable and may lead to : • uterine hyperstimulation • placental abruption • fetal hypoxia • pulmonary or amniotic ﬂuid embolism • The risk of uterine rupture is rare,

Artificial rupture of membranes (ARM) • two layers of membrane surrounding the fetus: • the amnion is closest to the fetus, and the chorion is nearest to the decidua. • ARM is simple process that can be used in an attempt to induce labor if : • *the cervix is favorable • *the presenting part is ﬁxed in the pelvis, • *the woman does not want to use drugs such as PGE2 or oxytocin, • *there is a risk of hyper stimulation if using PGE2.

Prior to the procedure: • an abdominal examination • the lie is longitudinal • the presenting part is engaged • the fetal heart rate is within normal limits • a VE is done to assess the cervix, conﬁrm the presentation and station and to exclude possible cord presentation or vasa praevia. • the bag of membranes lying in front of the presenting part (forewaters) is ruptured with the use of an amnihook or similar device to release the amniotic ﬂuid.

The ﬂuid is assessed for: • color • Volume • following ARM it may be possible to distinguish other features on the presenting part to identify the position of the fetus. • After the procedure the woman is made comfortable • the fetal heart is auscultated • all ﬁndings are recorded in the maternity notes.

The longer the interval between ARM and birth increases the risk of the woman developing chorio-amnionitis as a result of an ascending infection from the genital tract leading to an increased risk of perinatal mortality • For this reason if a decision has been made to induce labor for perceived risks it is common practice to start an oxytocin infusion within a few hours

Changes to ripen the cervix are thought to be in response to prostaglandin produced by the amnion and cervix. • In pregnancy the chorion provides a barrier to the amnion and fetus from the vagina and cervix. • Prostaglandin dehydrogenase (PGDH) is an enzyme produced by the chorion that breaks down prostaglandin.

actions of this enzyme the changes in the cervix do not take place and pre-term labour is avoided • VE in late pregnancy rapidly increases the concentration of circulating prostaglandins. • This change occurs both in sweeping the membranes and with ARM.

It is thought it is the disruption of the attachment of the membranes to the uterine wall that facilitates this change. • in labouring women the part of the chorion that was in close contact with the cervical os released less PGDH allowing the prostaglandin from the amnion to come into contact with the cervix and facilitate ripening of the cervix. The theory is that if an ARM is performed too early the action of the amniotic prostaglandins on the cervix is lost.

Oxytocin • Oxytocin is synthesized in the hypothalamus and then transported to the posterior lobe of the pituitary gland from where it is episodically released to act on smooth muscle. • The number of oxytocin receptors in the myometrium signiﬁcantly increases by term increasing uterine oxytocin sensitivity

In its synthetic form, oxytocin (Syntocinon) is a powerful uterotonic agent that may be used as part of the process for IOL following ARM. • do not recommend the use of oxytocin alone for IOL, or the use of ARM and oxytocin as a ‘primary method’ of IOL, unless the use of vaginal PGE2 is speciﬁcally contraindicated.

Oxytocin should be administered by slow intravenous infusion using an infusion pump or syringe driver with non-return valve. • The infusion rate should follow NHS Trust protocol and the maximum rate of 0.2 units/minute should not be exceeded • The dose is titrated against uterine activity, usually increasing the dose every 30 minutes with the aim of 3–4 contractions every 10 minutes with each contraction lasting approximately one minute, using the lowest possible dose.

If contractions exceed this rate, or the contractions fail to establish, the infusion must be stopped and the case reviewed to determine the next step. • There should be an interval of at least six hours between administration of prostaglandins and commencement of an oxytocin infusion.

When using an oxytocin infusion the fetal heart rate and uterine activity should be monitored using continuous EFM to ensure the fetus does not become compromised by the induced uterine contractions. • There is a risk of hyperstimulation and hypertonic uterus leading to fetal compromise

Even with the use of the CTG the midwife still has an important role to play in assessing the woman's progress. • The graphic representation on the CTG provides an indication of the frequency of the contractions but does not necessarily provide an accurate representation of the length and strength of the contractions, and for this reason it is important that the midwife continues to palpate the uterus to assess contractions for their length and strength.

assess maternal and fetal wellbeing the midwife has a valuable opportunity to be with the woman and to use her ‘art’ to make a more holistic assessment of the woman and how she is responding to the process and what she wants and needs at this time.

Risks associated with use of intravenous oxytocin include: • Uterine hyper stimulation or hyper tonus • Fetal hypoxia and asphyxia • Uterine rupture • Fluid retention as a result of the antidiuretic effect of oxytocin • Postpartum haemorrhage • Amniotic fluid embolism (AFE)

Thank you

بسم الله الرحمن الرحيم