Flashcards in Induction and Augmentation of Labor Deck (43):
List maternal indications for IOL
2) renal disease
3) chronic pulmonary disease
4) cholestasis of pregnancy
5) gHTN or pre-eclampsia w/out severe features @ 37w
6) pre-eclampsia w/ severe features = ASAP
7) >41w GA - recommended at 42w0; indicated at 42w6d
9) PROM after 34w
List fetal indications for IOL
3) non-reassuring fetal testing
4) multiple gestation
What are contraindications to IOL?
1) problems of placentation (e.g. previa, prolapse)
2) hx myomectomy entering endometrial cavity
3) classical uterine incision
4) transverse lie
5) Cat 3 FHT
6) active genital herpes
7) elective IOL at <39w
What are maternal clinical considerations prior to IOL?
1) valid indication
2) no contraindications to vaginal labor/delivery
4) Bishop score via cervical exam
5) review risks, benefits, alternatives to IOL
What are fetal clinical considerations prior to IOL?
1) GA based on final EDD - fetal lung maturity
2) fetal presentation and lie
4) Confirm Cat 1 FHT
What are risk factors for failed IOL?
3) low Bishop score
4) shorter stature
5) higher BMI
Describe Bishop scoring system
an assessment of cervical status to determine success of IOL
- >/= 8 --> favorable cervix
- =6 --> unfavorable cervix; may require ripening
0: posterior, firm, cervical length >4cm, 0/-3
1: midline, medium, 2-4cm, 1-2/-2
2: anterior, soft, 1-2cm, 3-4/-1 to 0
3: cervical length <1cm, >5cm/+1 to +2
Describe the latent phase of labor according to Zhang's labor curve
regular, q10-20min, uterine ctxns lasting 15-20s --> intensifies to q5-7mins, lasting 30-40s
Describe active labor according to Zhang's labor curve
cervical dilation starts at ~6cm --> ends with complete dilation
- nullips: 0.5-0.7cm/h or faster
- multips: 0.5-1.3cm/h
What are the 4 Ps?
What are considered adequate contractions on pitocin?
q2-3mins lasting 60-90s
50-60 peak, 10-15 resting tone
What is therapeutic rest?
"treats" prolonged latent phase
morphine sulfate IM +/- phenergan or vistaril
What is dx for protracted active phase?
multips: <0.5 - 1.5cm/h
nullips: <0.5 to 1.2cm/h
What is dx for arrest of active phase?
6cm or more, ROM, + one of following:
- 4h+ of adequate ctxn (>200MVU)
- 6h+ of inadequate ctxn
What is the mean duration of the second stage?
no max length identified
What is dx for protraction descent?
What is dx for arrest of descent?
0 descent - time period not officially identified
+1h for epidural
What are risks of >2h second stage?
1) low 5 min APGAR
2) increased neonatal depression
3) NICU admission
4) perineal trauma
7) instrumental deliveries
What are risk factors affecting length of the second stage?
2) birth weight
3) OP position
5) epidural anesthesia
6) fetal station at complete dilation
7) delayed pushing
What are indications for C/S in the setting of IOL or augmentation?
1) >/= 6cm, ROM, and no cervical change over 4h
2) no cervical change in 6h of pit + inadequate uterine activity
3) failed induction = little to no cervical change for at least 24h in setting of pit + ROM
List cervical ripening agents
1) prostaglandin E2: dinoprostone (Cervidil or Prepidil)
2) prostaglandin E1: misoprostol (Cytotec) *off-label*
What are cervical ripening agents contraindicated?
1) prior to 40w GA
2) uterine scarring
What is the MOA of prostaglandins?
increase submucosal water content of cervix --> dissolution of collagen bundles
How should FHT be monitored during cervical ripening?
EFM for 0.5-2h
Continue to monitor if regular ctxns continue
0.5mg gel in 2.5mL syringe q6-12h
max 3 doses = 1.5mg
pit can start 6-12h after last dose
10mg (0.3mg/h) q6h
max 3 doses = 30mg
pit can start 30-60min after removal
25mcg per vagina q3-6h
- mostly likely for vaginal birth w/in 24h
- most likely for tachysystole
25-50mcg PO q3-6h
- lowest c/s rate
- less PPH and better NB outcomes
pit can start 4h after last dose
What is Cytotec contraindicated in cervical ripening?
- uterine scars
- >3 ctxns in 10 mins
What is a contraindication to dilation w/ balloon?
placenta previa; low-lying placenta
true or false:
Balloons take longer than prostaglandins to ripen a cervix.
may even be faster when used w/ another agent
What is the mechanism of membrane stripping?
releases prostaglandins --> ripening
Describe a typical dose of castor oil
2oz or 60mL in 2 doses
What are the adverse effects of castor oil?
--> dehydration - PO 8oz fluids w/ electrolytes q1h
List uterotonic agents
1) oxytocin (Pitocin, Syntocinon)
2) nipple stimulation
contraindications to oxytocin
- inclusive of contraindications to NSVD
- pulmonary edema
- inappropriate staffing ratios
Why is pulmonary edema a contraindication to the use of oxytocin?
oxytocin = antidiuretic
--> inc edema, water toxicity, hyponatremia
What steps should be taken in the case of fetal compromise while augmenting with pitocin?
1) move to lateral position
2) +/- fluid bolus and terbutaline 0.25mg subQ
3) notify physician
4) restart after 15-30mins of Cat 1 FHT
When should oxytocin be discontinued?
- after 10-12h (if not in active labor)
- once active labor has begun
How is nipple stimulation performed?
roll one or both nipples with fingers OR use breast pump for 2mins, stop for 2mins, etc until contractions begin
What is the most common risk of AROM?
infection (e.g. chorioamnionitis, endometritis)
What is the most severe risk of AROM?
What are indications for augmentation of labor?
1) >/= 4h w/out cervical change after 5cm
2) prolonged latent phase