L4: Labor (Physiology)

Question 1

Physiology of Labor

Answer 1

• 1st Stage
• 2nd Stage
• 3rd Stage

Question 2

Physiology of 1st Stage of Labor

Answer 2

Question 3

Def of 1st Stage of Labor

Answer 3

Stage of cervical dilatation up to fully dilated cervix.

Question 4

Extent of 1st Stage of Labor

Answer 4

Starts e onset of labor & ends e full cervical dilatation.

Question 5

Duration of 1st Stage of Labor

Answer 5

• In nullipara: 10-16 hours.
• In multipara: 6-8 hours.

Question 6

Events of 1st Stage of Labor

Answer 6

• Cervical Effacement
• Cervical Dilatation

Question 7

Def of Cervical Effacement

Answer 7

Taking up of cervix into LUS leading to shortening of cervical canal.

Question 8

Mechanism of Cervical Effacement

Answer 8

• Muscle fibers of internal os are taken up into LUS followed by taking up of muscles of cervical canal.

Question 9

Relation of Cervical Effacement to Dilatation

Answer 9

• In nullipara: Effacement occurs at 1st followed by dilatation.
• In multipara: Both effacement & dilatation occur simultaneously.

Question 10

Assessment of Cervical Effacement

Answer 10

a) Zero: If cervical canal is > 2 cm.
b) 50% effaced: If cervical canal is 1 cm.
c) 100% effaced: If cervical canal is < 0.25 cm.

Question 11

Def of Cervical Dilatation

Answer 11

Progressive opening of cervix.

Question 12

Causes “Triggers” of Cervical Dilatation

Answer 12

Question 13

Mechanism of Cervical Dilatation

Answer 13

Cervical dilatation occurs from above downwards (internal os dilates at 1st then cervical canal & finally external os dilates).

Question 14

Assessment of Cervical Dilatation

Answer 14

Question 15

Pattern of Cervical Dilatation

Answer 15

• Latent Phase
• Active Phase

Question 16

Pattern of Cervical Dilatation

• Latent Phase

Answer 16

Question 17

Pattern of Cervical Dilatation

• Active Phase

Answer 17

Question 18

Extent of 2nd Stage of Labor

Answer 18

Starts è full cervical dilatation & ends è delivery of fetus.

Question 19

Def of 2nd Stage of Labor

Answer 19

Stage of expulsion of fetus

Question 20

Duration of 2nd Stage of Labor

Answer 20

• In nullipara: 1-2 hours.
• In multipara: 0.5-1 hour.

Question 21

Powers participating in 2nd Stage of Labor

Answer 21

• Fetal axis pressure.
• Bearing down main force in 2nd stage

Question 22

Phases of 2nd Stage of Labor

Answer 22

• Vaginal descent phase
• Perineal Phase
• After Expulsion of Head

Question 23

Phases of 2nd Stage of Labor

• Vaginal Descent Phase

Answer 23

Question 24

Phases of 2nd Stage of Labor

• Perineal Phase

Question 25

Perineal Reflex

Answer 25

**Definition:** When head stretches perineum, there is reflex involuntary bearing down è each uterine contraction.

Question 26

Crowning

Answer 26

**Definition:** - Permanent distension of vaginal introitus by fetal head so that vulva appears like crown on head & head doesn't recede in () contractions due to passage of BPD through pelvic outlet. **Importance:** - Natural test for pelvic outlet (if occurred → no contracted outlet).

Question 27

After Expulsion of Head

Answer 27

- There is short period of rest or weak contractions then strong contractions occur leading to expulsion of shoulders, trunk & LLs.

Question 28

Def of **3rd Stage of Labor**

Answer 28

Stage of separation, descent & expulsion of placenta & membranes.

Question 29

Extent of **3rd Stage of Labor**

Answer 29

Starts after expulsion of fetus & ends è expulsion of placenta & membranes.

Question 30

Duration of **3rd Stage of Labor**

Answer 30

10-30 minutes in both nullipara & multipara.

Question 31

Phases of **3rd Stage of Labor**

Answer 31

- Separation of placenta - Descent of placenta - Expulsion of placenta

Question 32

Mechanism of **Separation of Placenta**

Answer 32

Question 33

Signs of Separation of Placenta

Answer 33

Question 34

Descent of Placenta

Answer 34

Into LUS & upper vagina.

Question 35

Expulsion of Placenta

Answer 35

- From vagina, either by patient's own expulsive efforts (bearing down) alone or aided by traction on cord.

Question 36

Methods of **Delivery of Placenta**

Answer 36

Question 37

Separation of Placenta - Incidence

Answer 37

Question 38

Separation of Placenta - Separation

Answer 38

Question 39

Separation of Placenta - Expulsion

Answer 39

Question 40

Separation of Placenta - Bleeding

Answer 40

Question 41

Separation of Placenta - Retention of Membranes

Answer 41