Dr. shakeri Amir hospital

Labor induction Definition -induction -augmentation 35% of labors are induced or augmented Indicated when the benefits to either mother or fetus outweight those of continuing the pregnancy

Indications Ruptured membranes with chorioamnionitis Severe preeclampsia Membrane rupture without labor Gestational hypertension Nonreassuring fetal status Postterm pregnancy Maternal medical condition such as chronic H.T and diabetes

Contraindications Fetal factors(appreciable macrosomia, multifetal gestation, severe hydrocephalus, malpresentation, nonreassuring fetal status Maternal factors(prior incision type, contracted pelvic anatomy, abnormal placentation, active genital herpes infection and cervical cancer

Risks Matenal complication rates that are increased with induction -chorioamnionitis -uterine atony -C/S. especially increased in NP X2-3. in nulliparas >41w with unengaged vertex the risk increases 12-fold.No increased risk if the engaged fetal head is OP

Cervical favorability One method used to predict outcome of induction is the score described by Bishop Bishop score of 9 conveys a high likelihood for a successful induction In unfavorable cervix -methods use for cervical ripening include. pharmacological techniques(PGE1-PGE2). mechanical techniques

Bishop score ScoreDilateEffStationC.Consisten cy c.position 0closed0-30%-3firmpost 11-2cm40-50%-2mediummid 23-4cm60-70%-1,0softant 3≥5cm≥80%+1,+2--

Prostaglandin E2(Dinoprostone) Its gel form-Prepidil-is available in a 2.5 ml syringe for application of 0.5 mg of dinoprostone -the gel is deposite just the internal cervical os -after application she remains declined for 30 min - doses may be repeated every 6 h -maximum three doses in 24 h Vaginal insert form( 10mg)-Cervidil-placed in posterior vaginal cervix(slower release of medication-0.3mg/h) -following insertion she should remain recumbent for at least 2h/the insert is removed after 12h or with labor onset

Administration In or near the delivery suite Uterine activity and FHR monitoring should be performed contraction begins in first hour and show peak activity in the first 4h Oxytocin induction should be delayed for 6 to12 hours following PG administration

Side effects Uterine tachysystole in 1 to 5% Uterine tachysystol is defined as≥6 contractions in a 10 minute period Uterine hypertonus is defined as a single contraction lasting longer than 2 minutes Uterine hyperstimulation is when either condition leads a nonreassuring FHR pattern

In preexisting spontaneous labor, PG used is not recommended If hyperstimulation occurs with the 10-mg insert, its removed by pulling on the tail of the surrounding net sac will usually reverse this effect Irrigation to remove the gel has not been helpful CI Asthma, glucoma, increased intraocular pressure Recommendation caution aganis its use in PROM

Prostaglandin E1 (Cytotec) Approved as a100 or 200µg tablet for prevention of peptic ulcers May be administered orally or vaginally 100µg oral dose was as effective as 25µg intravaginal dose Tablets are stable at room temperature Is the PG of choice at both Parkland and Birmingham Hospital The ACOG recommended the 25µg dose(a fourth of a 100µgtablets) In prior uterine surgery, including C/S,the use of cytotec is contraindicated

Nitric oxide donors Isosorbide mononitrate did not enhance cervical ripening either in early pregnancy or at term Did not shorten time to vaginal delivery

Mechanical techniques 1-Transvaginal catheter -80ml Foley transcervical catheter balloon was significantly more effective than 30ml Foley -did not increase the risk of PTL in the next pregnancy 2-Extra amnionic saline infusion(EASI) -room temperature normal saline is infused through the catheter of foley ( ml/h )

3-Hygroscopic cervical dilators -ascending infection have not been verified -their used to be safe -anaphylaxis has followed laminaria insertion -are attractive because of their low cost and easy placement and removed -longer induction to delivery time compared with EASI 4-Membrane stripping for labor induction -two thirds of stripping group entered spontaneous labor within 72h

oxytocin Is one of the most commonly used medication in USA The first polypeptide hormone synthesized An achievement for which the 1955 Nobel Prize in chemistry was awarded With oxytocin use, ACOG recommended FHR and contraction monitoring similar to any high risk pregnancy

IV oxytocin administrstion The goal is to effective uterine activity sufficient to produce cervical change and fetal descent, while avoiding development of nonreassuring fetal status Oxytocin should be discontinued if -the number of contractions greater than5 in a 10 min -seven in a 15 min period -persistant nonreassuring FHR pattern Discontinuation of oxytocin rapidly decreases the frequency of contractions Mean half-life is 5 minutes

Response is highly variable and depends on preexisting uterin activity, cervical status, pregnancy duration and biological differences Uterine response increases from 20 to 30 weeks and increases rapidly at term A 1-ml ampule containing 10 units usually is dilutaed into 1000ml of a crystalloid solution and administered by infusion pump

The Parkland Hospital protocol: -starting dose of oxytocin at 6 mU, with 6-mU/min increases every 40 min, but employs flexible dosing on hyperstimulation The Birmingham Hospital protocol : -begins oxytocin at 2mU/min and increases it as needed every 15 minutes to 4, 8, 12, 16, 20, 25, 30 m/min

Side effect Has amino-acid homology similar to vasopressin Has significant antidiuretic action When infused at doses of 20mU/min or more, renal free water clearance decreases marketly Water intoxication can lead to convultion, coma and even death If oxytocin is to be administered in high doses, its concentration should be increased rather than increasing the flow rate of dilute solution

Amniotomy A common indication for artificial rupture of membranes includes the need for direct monitoring of the FHR or uterine contractions Care should be taken to avoid disloding the fetal head, to minimize the risk of cord prolapse Fundal or suprapubic pressure may reduce the risk Some clinicians prefer to rupture membranes during a contraction FHR should be assessed before and immediately after amniotomy

Early amniotomy at 1 to 2 cm - associated with significant 4-hour shorter labor -increased incidence of chorioamnionitis Late amniotomy at 5 cm -accelerated spontaneous labor by 1 to 2 hours -C/S was not increased -no adverse perinatal effects -increased mild to moderate cord compression pattern

Amniotomy augmentation -perform amniotomy when labor is abnormally slow -significantly increases the incidence of chorioamnionitis