L22 - Birth

Question 1

What initiates labour?

Answer 1

Raised oestrogen (pro-labour)
decreased progesterone (pro pregnancy)
oxytocin release by mothers post pit gland
prostaglandins from the decidua
together creating uterine contractions
mechanical stimulation of uterus and cervix caused by overstretching and pressure from the pp (presenting part)

Question 2

first stage of labour - latent phase

Answer 2

effacement of cervix
occurs before dilatation
contractions
intensity varies

Question 3

diagnosis of active labour

Answer 3

painful regular contractions 
cervical effacement 
dilatation of cervix of 4cm or more 
dilate 0.5 cm per hour
midwives check changes in body language/noise
vaginal exam every 4 hours

Question 4

Second stage of labour

Answer 4

looking for signs that want to birth

from full dilatation to delivery

Question 5

Describe the fontanelles ?

Answer 5

Anterior fontanelle - bregma
diamond shaped intersecting 4 sutures
2x3 cm
closes at 18 months

posterior fontanelle
Y shaped intersection of 3 sutures
closes at 6-8 weeks

Question 6

stage 3 of labour

Answer 6

delivery of placenta
blood loss 300-500ml
inspection of placenta to ensure completion
EITHER -
active management (CCT)
oxytocin - given in maternal thigh, causes sustained uterine contraction
aids delivery of placenta
OR -
physiological - mother naturally expels placenta and membranes with contractions

Question 7

why monitor fetus in labour?

Answer 7

to detect fetal hypoxia and deliver baby if needed

Question 8

How to monitor fetus during labour?

Answer 8

Screening the fetal heart rate by
Intermittent auscultation by Pinard or Sonicaid - every 15 mins to listen to baby HR for 16 seconds. if baby is stressed its HR will drop after a contraction. in second stage of labour listen every 5 minutes
Any abnormality means use CTG
CTG (cardiotocograph) - look at contractions and fetal heart. continous print out of fetal HR and contractions. abdominal US detects cardiac movements hence HR
A clip applied to fetal scalp FSE - detects R-R wave of fetal ECG
CTG is highly sensitive if baby okay. but poorly specific. if abnormal only few babies are hypoxic.
Need to check CTG findings with FBS - fetal blood sampling

Question 9

How do you do fetal blood sampling?

Answer 9

speculum into vagina
small prick made on babys head and blood collected via glass pipette
fill capillary tube
pH and base excess result
contraindications - HIV, HepB, fetal bleeding disorder, prematurity less than 32 weeks