Pregnancy and birth Flashcards Preview

203: Theme 2: Reproductive system, fetal development, pregnancy and birth > Pregnancy and birth > Flashcards

Flashcards in Pregnancy and birth Deck (21)
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1
Q

Initiation of labour

A

Remains uncertain

Multifactorial in origin

  • hormonal
  • mechanical

Fetal hypothalamus is triggered

Maternal post pituitary releases oxytocin

Decidua releases prostaglandins

2
Q

Hormones in the initiation of labour

A

Increase in pro-labour hormone

Decrease in progesterone pro-pregnancy hormone

Release of oxytocin by the mother’s posterior pituitary gland

Prostaglandins from the decidua

Together creating uterine contractions

Mechanical stimulation of the uterus and cervix caused by overstretching and pressure from the pp

3
Q

Stages of labour

A

Latent phase

1st stage of labour

2nd stage of labour

3rd stage of labour

4
Q

Latent phase of labour

A

Effacement of cervix

Contractions

Intensity varies

5
Q

Diagnosis of active labour

A

Painful regular contractions

Cervical effacement

Dilation of the cervix of 4cms or more

6
Q

Active labour/ first stage of labour

A

Established labour to full cervical dilation

Vaginal examinations

Average is 0.5cm/ hour

7
Q

Second stage of labuor

A

From full dilation to the delivery of the baby

8
Q

Pelvic inlet

A

The brim is oval except where the promontory projects

The anteroposterior diameter is 12cm

9
Q

Pelvic outlet

A

The outlet is diamond shaped

Has three diameters

  • anteroposterior
  • oblique
  • transverse
10
Q

Fontanelles

A

Anterior fontanelle (bregma)

  • diamond shaped intersection of 4 sutures
  • 2x3 cms
  • closes at 18 months

Posterior fontanelle

  • Y shaped intersection of 3 sutures
  • closes at 6-8 weeks
11
Q

Diameters of the fetal skull

A

Suboccipitobregmatic (9.5cms)- OA position

Occipitofrontal (11cms)- OP position

Supraoccipitomental (13.5cms)- brow

Submentalbrgmatic (9.5cms)- face

12
Q

Mechanisms of birth (9)

A
  1. Head at pelvic brim OT position
  2. Flexion of neck
  3. Head descends and engages
  4. Head reaches pelvic floor- rotates to OA
  5. Head delivers by extension
  6. Head restitutes
  7. Shoulders rotate into anterior/ posterior diameter of pelvis
  8. Anterior shoulder delivered by lateral flexion from downward pressure on baby’s head
  9. Posterior shoulder by upward lateral flexion
13
Q

Third stage of labour

A

Delivery of placenta

Normal estimated blood loss 300-500 mls

Inspection of placenta to ensure completion

14
Q

2 types of third stages of labour

A

Active management

Physiological

15
Q

Active management of third stage

A

Oxytocin i.m. given into maternal thigh

Cause sustained uterine contraction

Aids delivery of the placenta and contraction of the placental bed

Decreases risk of post-partum haemoorhage

16
Q

Physiological third stage

A

Mother naturally expels the placenta membrane with contractions

17
Q

Fetal monitoring in labour

A

To detect fetal hypoxia and deliver baby is needed

Intermittent auscultation by Pinard or Sonicad

CTG

FBS

18
Q

Intermittent auscultation

A

Every 15 mins before and after a contraction during the first stage

Every 5 mins in the second stage

Any abnormality heard would lead to the use of the CTG

19
Q

Cardiotograph

A

Continuous print out of fetal heart rate and contraction

  • abdominal ultrasound (detects cardiac movements)
  • a clip applied to the fetal scalp (detects R-R wave of fetal ECG)

Most usual is abdominal ultrasound

20
Q

Fetal blood sampling

A

CTG is highly sensitive but poorly specific

Use of CTG leads to 4 fold increase in C-sections for fetal distress

Need to check the CTG findings with FBS

21
Q

FBS

A

Stab on the fetal scalp

Blood collected via a glass pipette

pH and base excess result

Contraindications

  • infection such as HIV, hepatitis B
  • fetal bleeding disorder
  • prematurity less than 32 weeks