NORMAL LABOUR Flashcards
How many stages of labour are there?
3
When does the first stage of labour begin?
Painful regular contractions (prior to this there will be painless irrugelar uterine tightenings)
Cervical dilatation of 4 cm or more and effacement
What is effacement, in the context of labour?
When the cervix has spread so far that it now becomes part of the uterine lining.
Other than regular contractions and cervical dilatation, what else might happen that may signal (but not define) the beginning of labour?
Show - passage of a mucoid plug from the cervix, often blood stained
Rupturing of membranes
When does the first stage of labour end and the second stage begin?
Full dilation - 10 cm
What is monitored in the first part of labour?
Uterine contractions
Dilation of cervix
Descent of presenting part
What is the normal rate of cervical dilatation in nulliparous women in the first part of labour?
0.5-1 cm/h
What is the normal rate of cervical dilatation in multiparous women in the first part of labour?
1-2 cm/h
What is the name of the chart used to document the observations made in labour? What is the purpose of this chart?
Partogram - used to highlight slow progress, particularly a delay in cervical dilatation or failure of the presenting part to descend.
What are the three factors (3 P’s) that determine the progress through labour?
Passages
Passenger
Power
What are the boundaries of the pelvic inlet?
Pubic crest
Iliopectineal line
Sacral promontory
The widest diameter of the pelvic inlet lies in which line?
Transverse
How wide is the widest diameter of the pelvic inlet?
13 cm
What are the boundaries of the pelvic outlet?
Lower border of the pubic symphysis
Ischial spines
Tip of the sacrum/coccyx
The widest diameter of the pelvic outlet lies in which line?
Anteroposterior
How wide is the widest diameter of the pelvic outlet?
11 cm
What are the muscles of the pelvic floor that the fetus must pass through?
Levator ani group:
Pubococcygeus
Iliococcygeus
Internal obturator
Piriformis
What part of the anatomy is responsible for the propulsive contractions that deliver the fetus?
The upper uterine segment
What are the 3 layers of the myometrial component of the uterus?
Thin outer longitudinal layer
Thin inner circular layer
Thick middle spiral layer
When do uterine contractions start in pregnancy?
Quite early on. There are painless irregular contractions that will start from as early as the second trimester.
What do we call the painless, irregular contractions that start early on in pregnancy?
Braxton-Hicks contractions
What is progressive retraction, in the context of labour?
This describes the ability of the uterine muscles to not only relax and contract but to become progressively smaller resulting in dilatation of the cervix and eventually effacement.
What about the contractions during labour do we monitor ?
Strength
Frequency
Duration
In the first part of labour what is the usual range of rate of contractions?
Starts at about 2/3 contractions every 10 minutes and progresses to about 4/5 over 10 minutes. Each one lasting 60s.
As well as the uterus, which other muscles does the mother recruit in order to help with delivery of the baby?
Diaphragm
Abdominal muscles
What bones make up the cranium of the fetus?
2 frontal bones
2 parietal bones
1 occipital bone