Parturition Flashcards
What is the lengh of pregnancy on average?
40 weeks
What is the date called that someone is due to give birth?
The EDD (estimated due date) or delivery date
What is considered a term pregnancy?
37 - 42 weeks
What is considered preterm birth?
Before 37 weeks
What is considered post-term?
After 42 weeks
When is the first trimester?
Under 14 weeks
What is considered the second trimester?
14 - 26 weeks
What is considered the third trimester?
27 - 40 weeks
How do we calculate gestational age?
- Last menstraul cycle
- US dating (most acurate) (crown-rump length - most accurate from up to 13 weeks)
- Symp-fundal height (unreliable)
- Palpating uterus (unreliable)
How does the amniotic sac prevent parturition?
Prostaglandins are not released
How does the cervix ripen?
- Cervix need to stretch and open up, becomes more watery
- Cervix becomes effaced
- Becomes shorter
- Process mediated by prostaglandins
What factors maintain the pregnant state?
- Cervix
- Uterine quiescence
- Amniotic fluid (keeps prostaglandins in)
What does stage 1 of labour involve?
Cervix relaxes, causing it to dilaate and thin out
What does stage 2 of labour involve?
Uterine contractions increase in strength and infant is delivered
What does stage 3 of labour involve?
Placenta is expelled
What maintains the quiescent uterus?
Progesterone and relaxin
What causes the uterine ‘awakening’?
Increase in gap junction connectivity (prostaglandins), increase in oxytocin receptor numbers (estrogen)
What triggers the oxytocin release?
Ferguson reflex
What hormone causes the epulsion of the placenta and the final uterine contractions?
Oxytocin
What are the 2 phases in the first stage of labour?
Latent phase - <4 cm Active phase - 4 - 10 cm (fully) - Rupture of membranes
How much do we expect the baby to move per hour in the active phase?
1 cm per hour
What are the 7 stages in the 2nd stage of labour (essentially pushing out the baby)?
- Engagement
- Descent
- FLexion
- INternal rotation
- Extension
- External rotaation
- Expulsion
What is the difference in engagement between someone who has given birth before and someone who is having their first birth?
Engagement happens a lot closer to birth in someone who has given birth before
What are some examples of abnormal presentations of the baby?
- Breech (bottom first) (frank or complete)
- Footling breech
- Shoulder
- Face
- Brow
What is the normal and preferred presentation of the baby?
Cephalic presentation
What does intrapartum monitoring monitor?
- Progress of childbirth
- On partograph
- Cervical dilation measured
- Strength and number of uterine contractions
- Colour of amniotic fluid
- Fetal HR
How is the fetal Heart rate listened into?
Pinard stethoscope
What is a CTG?
Cardiotocography
- Records fetal heart beat and uterine contractions during pregnancy
Where are the majority of oxytocin receptors?
Fundus of uterus
