2. Stages of Labour
• Series of events that take place in the genital organ in an effort to
expel the viable products of conception out of the womb through the
vagina into the outer world is called labour.
• It may occur prior to 37 completed weeks, when it is called preterm
labour.
• Delivery is the expulsion or extraction of the viable fetus out of the
womb.
3. Types of labour
• Normal labour (Eutocia)
• Abnormal labour (Dystocia)
4. Normal labour
Labour is called normal if it fulfils the following criteria.
spontaneous in onset and at term
With vertex presentation
Without undue prolongation
Natural termination with minimal aids
Without having any complication affecting the health of the
mother/baby.
6. Causes of onset of labour
• Utrine distension
• Feto-placental contribution
• Oestrogen
• Progestron
• Prostaglandins
• Oxytocin
• Neurological factors
7. Oestrogen
• Increases the release of oxytocin from maternal pituitary
• Promotes the synthesis of receptors for oxytocin in the myometrium
and decidual
• Increases the excitability of the myometrial cell membranes
9. Progestrone
• It is the alteration in the oestrogen:progesterone ratio rather than the
fall in the absolute concentration of progestron which is linked with
the prostaglandin synthesis.
10. Prostaglandins
•Prostaglandins are the important factor which
initiate and maintain labour
•The major sites of synthesis of prostaglandins
are amnion, chorion, decidual cells and
myometrium.
11. False Labour pain
Features
Dull in nature and usually confined to the lower abdomen and groin.
Continuous and unrelated with hardening of the uterus.
Without any effect on dilatation of the cervix.
Usually relieved by medications.
12. True labour pain
Features
• Painful uterine contractions (labour pain) at regular intervals.
• Contraction with increasing intensity and duration
• Show
• Progressive effacement and dilatation of the cervix
• Formation of the bag of waters
14. First Stage of Labour
• This starts from the onset of true labour pain and ends with full
dilation of cervix. It is in other words the cervical stage of labour.
• Its average duration is 12 hours in primigravida and 6 hours in
multigravida.
• Total cervical dilation in 10 cm.
15. Second Stage of labour
•It starts from the full dilation of the cervix and
ends with expulsion of fetus from the birth
canal.
•Avarag duration is 2 hours in primigravida
and 1 hour in multipara.
16. Third Stage of labour
•It begins after the expulsion of fetus and ends
with expulsion of placenta and membranes, it
also involves the control of bleeding.
•A third stage lasting more than 30 minutes
should be considered abnormal.
17. Fourth Stage of labour
• It begins with the delivery of the placenta and ends two hours later
