obs and gyn

Question 1

define onset of labour

Answer 1

the point at which painful uterine contractions become regular and cervical dilation and effacement begins to progress.

Question 2

what are braxton hicks contractions

Answer 2

irregular contractions that occur throughout the third trimester

Question 3

what is effacement

Answer 3

softening of the cervix by shortening of collagen fibres pulling the cervix upwards into the lower uterine segment until it is flat

Question 4

when does the cervical show occur

Answer 4

when the uterus becomes effaced or the membranes rupture

Question 5

What happens in the first stage of labour

Answer 5

Latent phase: irregular contractions spaced between 5-30 minutes become more regular and the cervix slowly dilates up to 4cm. The membranes should rupture at this point.
Active phase: cervix begins to dilate up to 1cm per hour in nulliparous women and 2cm in multiparous women, up to 10cm.
During the active phase the fetus should have begun descent, flexion and internal rotation.

Question 6

define engagement

Answer 6

where the lowest presenting part of the fetus aligns with the ischial spines in the pelvic outlet.

Question 7

At what rate should the cervix dilate in the active first stage of labour in nulliparous and multiparous women

Answer 7

1cm per hour in nulliparous women and 2cm per hour in multiparous women

Question 8

how long should the active stage of labour last before intervention is needed to progress the labour

Answer 8

Shouldnt last longer than 16 hours. Nice recommends if the cervix hasn’t dilated a further 2cm after 4cm within 4 hours then slow progress is diagnosed and intervention may be needed.

Question 9

what position is the fetus in when it enters the pelvic inlet

Answer 9

the saggital suture should be transverse for best fit. It should then begin to descend, internally rotate 90 degrees and flex the head to fit through the pelvic outlet

Question 10

what is the best position for the fetus to fit through the pelvic outlet

Answer 10

occipitoanterior

Question 11

define the second stage of labour

Answer 11

from full cervical dilation until the baby is born

Question 12

define the passive stage of the second stage of labour

Answer 12

from full cervical dilation until the head reaches the pelvic floor causing the desire to push

Question 13

what happens in the active stage of the second stage of labour

Answer 13

When the woman begins pushing. This should take around 40 minutes in nulliparous woman and 20 minutes in multiparous woman. if it lasts more than 1 hour intervention will be needed as it is unlikely to be delivered spontaneously

Question 14

if the second stage of labour fails to progress what interventions can be used

Answer 14

forceps
ventouse
c-section

Question 15

why is it dangerous if the second stage of labour fails to progress

Answer 15

• maternal exhaustion
• fetal hypoxia
• fetal trauma risk increased

Question 16

Explain the mechanism of delivery

Answer 16

• fetus descends, internally rotates and has a flexed head as it moves through the pelvis
  when it reaches the pelvis outlet the head extends to be born. The head then spontaneously rotates 90 degrees (externally) back to the transverse position. The shoulders will lie in the anteroposterior diameter and and the head should be pulled downwards to allow the birth of the anterior shoulder. the posterior shoulder is delivered by lifting the head upwards whilst maintaining traction.

Question 17

Name causes of failure to progress

Answer 17

PASSAGE - abnormal pelvis shape, pathology blocking the uterus e.g tumour.
POWER - uterine hypoactivity,
PASSENGER - cephalopelvic disproportion, malposition/malpresentation, an extended head