Labour, Delivery,lactation Flashcards
What is parturition ?
Transition for pregnant to no pregnant state
What is labour ?
Physiologic process by which foetus is expelled from uterus
What is delivery ?
Method of expulsion of foetus
Which 2 physiological changes initiate labour ?
Uterine lining (decidua+myometrium) more excitable
Cervical ripening
What is the birth canal composed of ?
Pelvic minor Soft tissue (uterus,cervix,vagina,vulva)
How is the first stage of labour defined ?
Interval between onset of labour and full dilatation of cervix
What are the phases of the first stage of labour ?
Latent phase : onset of labour , slow cervical dilatation ,softening
Active phase : faster rate of change + regular contractions
What is the aim of the first stage of labour ?
Creation of the birth canal and descend of foetus
What is stage 2 of labour ?
Time between full dilatation of cervix (10 cm ) and delivery
Which changes occur during stage 2 of delivery ?
Changes in uterine contractions (direction) to expulsive
Descent of the foetus (crowning of head)
What are the 2 phases of stage 2 of labour ?
Passive : descent and rotation of head
Active: maternal effort to expel foetus
What is the 3rd stage of labour ?
Expulsion placenta and downward contraction of uterus
Which changes must happen to start labour ?
- creation of birth canal (cervical ripening:effacement and dilatation )
- myometrium more excitable for initiation of contractions
Which hormone inhibits contractions ? How ?
Progesterone, depresses responsiveness of uterus to oxytocin and reduces uterine prostaglandin release
What are the effects of oestrogen on the myometrium and on other hormones ?
Increases gap junction : increases contractility
Also increases number of oxytocin receptors in myometrium
Induce prostaglandin synthesis
Which changes in hormones occur near term are responsible for onset of labour ?
Increase in oestrogen:progesterone ration
Lead to increased excitability due to increased oxytocin receptors and contractility of myometrium Increase prostaglandin production leads to cervical ripening and aids in contraction
What are the effects of prostaglandin and what induces its release ?
Promote labour :
Powerful contractor of myometrium
Involved in cervical ripening
Production by decidua,myometrium and membrane induced by increased oestrogen:progesterone ratio, oxytocin ,rupture of membrane , cervical stretching