Session 8 parturition and maternal mortality

• The Stages of Labour?

  • First Stage (stage of dilatation)
  • Interval between the onset of labour and full cervical dilation
  • Creation of the birth canal
  • Two phases: • Latent phase – onset of labour with slow cervical dilation to 4 cm. Variable duration
  • Active phase – faster rate of cervical change, 1- 1.2 cm /hour, regular uterine contractions.
  • Second Stage (stage of expulsion of fetus)
  • Delivery of the foetus.
  • Third Stage (stage of expulsion of placenta)
  • Delivery of the placenta and membranes
• Foetal lie?

  • Longitudinal
  • Oblique
  • Transverse
• Foetal presentation?

  • Cephalic
  • Breech
• Labour is possibly inhibited by progesterone.
• The possible rise in oestrogen to progesterone ratio increases prostaglandin production. Prostaglandins induce/promote labour.
• • Oxytocin increases uterine contractions
  • During pregnancy there are a low number of oxytocin receptors
  • During pregnancy oxytocin release is inhibited by Relaxin and progesterone.
  • From 36 weeks oestrogen stimulates the production of myometrial oxytocin receptors.
  • Impulses from cervix and uterus have a positive feedback effect on oxytocin release
• Bishop score - Assesses the likelihood that spontaneous onset of labour will occur in the next few days.

  Assess: • Cervical position • Cervical consistency • Cervical effacement • Cervical dilatation • Fetal station.
• Induction methods?

  • Oxytocin - IV
  • Prostaglandins - gel, pessary, tablet
  • Amniotomy • Thought to cause local release of endogenous PG • Done using amnihook.
• Cervix is made up of collagen in a proteoglycan matrix.
• Ripening of cervix involves:

  • Reduction in collagen
  • Increase in glycosaminoglycans
  • Reduced aggregation of collagen fibres
• Uterine segments?

  • Upper segment contracts (and retracts) powerfully and with each contraction becomes slightly shorter and thicker. This draws up the weaker, thinner and more passive lower uterine segment.This helps in dilation of the cervix.
  • The lower segment, cervix, vagina, pelvic floor and vulval outlet form the birth canal
• Braxton Hicks contractions, also known as practice contractions or false labor, are sporadic uterine contractions that may start around six weeks into a pregnancy.
• Antepartum haemorrhage is bleeding from 24+0 weeks until birth of the child.
• Haemorrhage from a low lying placenta. Placenta praevia. - vasa praevia
• Haemorrhage from a normally sited placenta - Abruptio placentae.
• Abruptio placenta?

  • Associated with BP. Increasing parity.
  • Abnormal separation of the placenta from the uterus resulting in blood loss.
  • Sudden onset of severe and constant abdominal pain.
  • Hard (“wooden”) and very tender uterus.
  • ABCD of resuscitation, restoration of blood volume.
• The APGAR score is a quick way for health professionals to evaluate the health of all newborns at 1 and 5 minutes after birth and in response to resuscitation. 
• Maternal death - during pregnancy or upto 42 days after labour.

  42-365 days - late maternal death