OB ex 2: Induction/Augmentation

Full term

39-41wks

Induction

The deliberate initiation of uterine contractions prior to their spontaneous onset.

• does not necessarily mean labor will go faster.

Augmentation

Methods used to aid with labor progress.

Indications For Induction

• Post dates >42 wks.

• IUGR: intrauterine growth restriction, <10% —better for fetus to deliver than stay inutero

• PROM: premature rupture of membranes: ROM with no labor

• Fetal demise/distress

• Maternal distress (Preeclampsia, DM, AMA)

• Elective – optional induction for personal reasons, no medical indication, must be at least 39 weeks pregnant. 

Advanced maternal age (AMA)

35 and above

Home Remedies to Induce Labor

• Intercourse (semen)

• Exercise/walking, curb walking

• Caster oil

• Herbal teas, eating dates

• Breast stimulation (stimulates release of endogenous oxytocin- hard to regulate amount, may cause too many contractions)

Contraindications to Induction

• Previous vertical uterine incision(c-secton): VBAC’s controversial, decreased muscle strength

• Overdistended uterus: multiple gestation = weaker muscle = concern for uterine rupture

• Placenta previa: vaginal delivery contraindicated

Bisop score

assesses if cervix is ready for labor.

• A score over 8 indicates a successful vaginal birth. 

• A score of 6 or less is considered to be unfavorable for an induction. 

Criteria: Dilation, effacement, station, consistency (firm, soft, medium), position (posterior, middle, anterior).

Ripe cervix

is shortened, centered (anterior), softened, and partially dilated.

A cervix that is soft, starting to efface and dilate will dilate easier than a cervix that is very thick and firm. 

Ripening agents

used to soften the cervix, to prepare it for labor.

• Risks: overstimulation of the uterus (contractions are too long or too frequent), fetal distress. 

Misoprostol (Cytotec)

Ripening agent

• Approved for peptic ulcer disease: off-label use for induction

• PO or Intra-vaginal: Tablet placed next to cervix

• Contractions/cramping usually begin within 2-8 hrs

• Also used in PP hemorrhage

• Cost: ~30¢ per tablet

Dinoprostone (Prostaglandin Gel/Cervidil)

Ripening agent.

• Gel is applied to cervix and cannot be removed; Cervidil is on a string and placed near the uterus, string hangs out the vagina and can be removed at any time. 

• Contractions often begin within 30 min

• Cost: $500/dose + $70 for diaphragm

• FDA approved for cervical ripening.

Cervical Ripening Balloon “Cook Catheter”

• Procedure: application of local pressure stimulates the release of prostaglandins to ripen cervix; placed for 12 hours then removed or it will fall out with dilation

• can only put in if the water is NOT broken . 

• Advantages: simple, lower cost, fewer side effects

• Risks: infection, bleeding, ROM, placental disruption

Amniotomy; “Water Breaking”

Method for induction; artificial rupture of membranes (AROM) = babys head drops down to cervix.

• Procedure: perform SVE and use amnihook to poke hole in amniotic sac

• Advantages: potential to progress labor, assess fluid, access for internal fetal monitoring

• Risks: infection, decreased amniotic fluid may lead to cord compression, cord prolapse (would result in an  emergency c-section)

• Nursing considerations: Monitor temperature, fluid (clear/pinkish/straw colored=normal), and fetal heart tones.  

Oxytocin // Pitocin

stimulates uterine contractions 

Procedure

• Given via IV pump

• Start with small amounts and ↑ per protocol: diluted in NS

• Increased q 30-45 minutes

• Not to exceed 20 –40 mU/min

• Monitor VS q15 min & FHR continuously 

Oxytocin/Pitocin Risks/Side effects (High risk drug)

• Hypo/hypertension- monitor VS q15 min & FHR continuously 

• Antidiuretic effect along w/ ↑ IV fluids → H2O intoxication (symptoms: hypotension, tachycardia, arrhythmias) 

• Edema

• Not to exceed 20 –40 mU/min

  • Hyper-stimulation/tachysystole: (no rest in-between contractions, contractions lasting more than 2 minutes, more than 5 contractions in ten minutes)

  • Uterine rupture

  • Fetal distress --> hypoxia 

  • Cervical lacerations

  • ↑ discomfort d/t stronger contractions, may not shorten duration of labor

Tachysystole

no rest in-between contractions, contractions lasting more than 2 minutes, more than 5 contractions in ten minutes.

• may reduce fetal oxygenation = fetal distress