labour and birth Flashcards
what is a normal labour ?
spontaneous labour that occurs between 37 and 42 weeks of gestation, with a single cephalic, term healthy, live fetus with no maternal or fetal complications
what is the duration of a normal labour in primigravida vs multigravida ?
primigravida: 12-18 hours
multigravida: 6-10 hours
what is a precipitate labour ?
an unusually rapid labour ( combined first and second stage of labour)
what are the physiological changes that happen prior to the onset of labour ?
- increased oxytocin and prostaglandins
- formation of gap junctions between myometrial cells
- formation of lower uterine segment
- increased myometrial tone with irregular contractions
- cervical softening ( effacement and dilatation)
what are the suggested theories about the inset of labour ?
decrease in progesterone levels decrease in oxytocinase levels uterine distention increase in prostaglandin levels increase in fetal cortisone
how can we distinguish false labour pains ?
braxton hicks contractions are irregular , infrequent and there is no cervical dilatation associated with it
how can we distinguish true labour pains from false labour pains ?
true labour pains do not go away with analgesia or sleep
true labour pains are more frequent, more regular and more intense in strength and is associated with cervical dilatation
how many stages of labour are there ?
three main stages
what is the first stage of labour ?
full cervical dilatation
what are the different stages in the first stage of labour ?
latent phase
accelerated phase
how long does the first stage of labour last in primigravida and multi women ?
prima- 18 hrs
multi- 6-10 hrs
what is the difference between the latent phase and the accelerated phase in the first stage of labour ?
latent phase refers to the gradual dilatation of the cervix until 4 cms
the active phase refers to the accelerated dilatation of the cervix from 4cm to 10 cms
why is the duration of the first stage of labour shorter inn multi women ?
effacement and dilatation of the cervix happen simultaneously
what is the normal rate of dilatation of the cervix in multi women vs prima women ?
- 2 cm per hour in prima
1. 5 cm per hour in multi
what is the most common presentation of delivery in foetuses ?
cephalic presentation
what does vertex mean ?
when the baby lies in an attitude of flexion the part of the head presenting is called the vertex
what diameters are present in a cephalic vertex presentation ?
biparietal 9.5 cm
subocciptobregmatic 9.5 cm
what is the second stage of labour ?
expulsion of the fetus ( which is refers to the full dilatation of the cervix to the birth of the baby )
how long does the second stage of labour last in prima and in multi ?
prima - 2 hours max
multi - 1 hour max
provided the woman has efficient uterine contractions
what are efficient uterine contractions ?
3 contractions every 10 minutes each lasting one minute
what is the difference between the passive and active stages of the second stage of labour ?
- the passive stage is from finding of the full dilatation of the cervix but before or in absence of involuntary contractions
- the active stage the baby is visible and expulsion contractions are present
how is the patient instructed to strain/bear down ?
they are asked to strain with their uterine contractions and to relax in between
what are the stages of fetal expulsion in order ?
- descend
- engagement
- increased flexion
- internal rotation of the head
- extension
- restitution
- external rotation of the head / internal rotation of the shoulders
in what stage is delivery seen ?
in the extension part
why does descend happen ?
due to uterine contractions and bearing down
what is engagement ?
widest part of the baby’s head passes through the widest part of the pelvis
during engagement if a PV examination was to be performed what would be the finding ?
the vertex would be felt on the level of the ischial spine
why does increased flexion happen ?
due to meeting of the head at the levator ani
why does extension of the head happen ?
the resultant force that happens due to the uterine contractions that happen downward and forward and the the contractions of the levator ani that happen up wards and forwards - resultant force is forward - extension
by what mechanism does delivery happen ?
extension
at what stage of labour should bearing down be avoided?
1st stage of labour
what is the role of amniotomy in labour ?
induces labour by increasing prostaglandins
what is the most preferred position of delivery for the mother ?
lithotomy postition
what is the purpose of the Ritgen maneuver ?
to avoid perineal tears , support the head early
when is an episiotomy indicated ?
performed when needed just before crowning of the head to avoid extensive perineal tears and facilitate head delivery
what position does the fetus usually start to descend in n?
left occipito-anterior
what is the third stage of labour ?
placental expulsion
how long does the third stage of labour last ?
10-30 minutes
why must placental delivery happen in a short period of time ?
to avoid the reforming of the cervix and retention of the placenta
what are the signs of placental abruption/ 3rd stage of labour ?
gushing of blood
suprapubic buldge
elongation of the cord
what are the two different mechanisms of placental delivery ?
Schultze mechanism - central
Duncan’s mechanism - peripheral
which method of placental delivery is better ?
Schultze mechanism ( incidence of retainment is lower)
what is the active method for the management of the third stage of labour ?
injection of methergine oxytocin
