25. induction and augmentation of labor

Question 1

what is induction of labor?

Answer 1

a process whereby labor is initiated by artificial means after an appropriate assessment of the mother and fetus. In the case of high-risk pregnancies, induction is necessary to reduce the risk of morbidity to the mother and her fetus.

Question 2

what is Augmentation?

Answer 2

artificial stimulation of labor that has begun spontaneously but the contractions are inadequate (promote adequate contractions)

Question 3

what are the maternal indications for induction?

Answer 3

Preeclampsia
Diabetes mellitus
Heart disease

Question 4

what are the Fetoplacental indications for induction?

Answer 4

• Prolonged pregnancy (postterm)
• Intrauterine growth restriction (IUGR)
• Abnormal fetal testing
• Rh incompatibility
• Fetal abnormality
• Premature rupture of membranes
• Chorioamnionitis

Question 5

what are the maternal indications for Augmentation?

Answer 5

• Abnormal labor (in the presence of
  inadequate uterine activity)
• Prolonged latent phase
• Prolonged active phase

Question 6

what are the maternal contraindications for induction?

Answer 6

-	Absolute contracted pelvis 
Relative contraindications
-	Prior uterine surgery
-	Prior classic cesarean incision
-	Complete transection of uterus
-	Overdistended uterus

Question 7

what are the Fetoplacental contraindications for induction?

Answer 7

• Preterm fetus without lung maturity
• Acute fetal distress
• Transverse fetal lie
• Abnormal presentation

Question 8

which drug is used for the induction and augmentation of labor?

Answer 8

Synthetic oxytocin (brand name Pitocin) 
Administered continuously via IV drip

Question 9

in what dose is Oxytocin given?

Answer 9

initial dose (0.5 to 6 mU/min')
time between dose increments (10 to 60 min')
and maximum dose (16 to 64 mU/min').

*While oxytocin is given, continuous monitoring of uterine activity and FHR is indicated so that the dose can be adjusted properly. In addition, maternal blood pressure should be monitored because pitocin may be associated with maternal hypotension.

Question 10

what is Bishop score (cervix score)?

Answer 10

a pre-labor scoring system that helps to determine the status of the cervix (favorable or unfavorable) for successful vaginal delivery; used in predicting whether induction of labor will be required.

Question 11

what is the Bishop score based on?

Answer 11

the station of the presenting part and 4 characteristics of the cervix: 1.dilation, 2.effacement, 3.consistency, and 4.position
DECP

Question 12

how is the Bishop score divided?

Answer 12

score ≥ 6 as favorable and a score ≤ 3 as unfavorable; scores of 4-5 are in a gray zone

Question 13

what is pre-induction cervical ripening?

Answer 13

when the cervical status is unfavorable, a ripening process is employed before induction aiming to shorten the duration of induction and maximize the possibility of vaginal delivery

Question 14

what are the 4 methods for ripening?

Answer 14

1. Prostaglandins
2. Ballon catheter
3. Laminaria sticks (osmotic dilators)
4. Hegar dilator set

Question 15

how are prostaglandins used for ripening?

Answer 15

Work by inducing cervical remodeling (↑ collagenase activity), cervical dilation, and uterine contractions.
PGE2 gel, PGE2 pessary, or PGE1 (misoprostol)

Question 16

how is a Balloon catheter used for ripening?

Answer 16

insertion of Foley catheter (filled by 30-60 mL) into the cervix.

Question 17

how are Laminaria sticks used for ripening?

Answer 17

organic/synthetic material inserted into the vagina/cervix, absorbing water, dilating and enlarging in size (resulting in cervical dilation). Usually inserted for up to 24 h’.

Question 18

how is a Hegar dilator set used for ripening?

Answer 18

consists of metal rods with increasing size (maximum diameter 26 mm); provides progressive cervical dilation by mechanical means.

Question 19

how is an amniotomy performed?

Answer 19

with an ‘amnio-hook’ that is used to puncture the amniotic sac around the fetus and release some of the amniotic fluid.

**After an amniotomy is performed, a careful examination should be taken to ensure that prolapse of the umbilical cord has not occurred