Induction of Labor Is the careful initiation of uterine contractions before their spontaneous onset. Is the use of physical or chemical stimulants to initiate or intensify uterine contractions. The need for initiating labor may arise from maternal or fetal sources. E.g. PIH, postterm pregnancy, D.M, PROM, I.U.F.D (Intra Uterine Fetal death). Elective induction may be indicated for the woman who has a history of precipitate labor to avoid unexpected out of hospital birth. There are a number of medically approved methods to induce labor; they include chemical induction with prostaglandins, oxytocin and mechanical as rupture of membranes.
Prostaglandins A prostaglandin gel for local application to the cervix has been formulated to soften the cervix and induce labor. For those women whose cervix is unfavorable, induction using PGE is more effective than using oxytocin. A 30 minutes electronic monitoring of FHR and uterine contractions is done to establish base line data. The physician instills 0.5 mg of PGE intracervically using a plastic catheter. The catheter is then removed. The woman remains in bed for 30 minutes, then may ambulate. FHR, BP and pulse are monitored at least every 30 minutes. Contractions usually begins 1/2 hour after administration of gel, the time of contraction is recorded.
Prostaglandins Progress of labor is recorded. Any hypertonic contractions of the uterus are reported immediately. If the woman doesn`t deliver within 24 hours, the cervix is reassessed and an induction using oxytocin is done if indicated and depend how much cervix is dilated. Because prostaglandin administration is effective, free of side effects and non invasive, some authorities believe it will replace amniotomy and oxytocin as the method of choice for induction of labor. The woman is kept informed of the progress of labor.
Oxytocin May be used either to induce the labor process or to augment a labor that is progressing slowly because of inadequate uterine contraction, or to assess fetal response to the stress of contractions (CTG). Indications: Prolonged pregnancy. Preterm delivery in diabetic mother. Severe Preeclampsia, Abruptio placenta or I.U.F.D. Multigravida with a history of precipitate labor. Prolonged rupture of membrane. Management of abortions.
Oxytocin Contraindications: Fetopelvic disproportion. Fetal distress. Previous uterine surgery. Over distended uterus e.g. multiple pregnancy. Previous CS Complication of Oxytocin: Maternal: tetanic contractions, Abruptio placenta, Postpartum hemorrhage, infection, DIC, Amniotic fluid embolism, anxiety and fear. Fetal: Asphyxia, Hypoxia, physical injury and Prematurity.
Oxytocin 10 IU of oxytocin is added to 1L of 5% dextrose or saline solution. Initial dose 2-5 iu/minute via constant infusion pump. Dose is increased every minutes until dose is 20 iu/minute per minute. Monitor the woman's BP, P, respiratory rate, contractions and FHR every 15 minutes. If FHR indicate distress or if contractions last 70 seconds or more, reduce or discontinue administration immediately. Increase IV solution without oxytocin, give O 2, turn on her left side and call the physician.
Amniotomy Transcervical amniotomy or artificial rupture of membranes can be used to stimulate labor. The cervix should be soft, partially effected and slightly dilated with presenting part engaged. Vulva is cleansed. Simple rupture of the membranes using sharp instrument passes over a finger into the cervix will allow the discharge of amniotic fluid. Procedure is explained to the woman, FHR recorded. Note and record amount and quality of fluid (clear, color, bloody, meconium…).
Amniotomy Artificial rupture of the membranes is often done to augment labor already in progress, since the membranes serve as a barrier against infection. Delivery is usually accomplished soon after the membranes have been ruptured artificially. Some obstetricians prefer to first stimulate the uterus with IV oxytocin and as soon as good contractions are evident, rupture the membranes. Others prefer merely to rupture the membranes.
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