Labour + Delivery

Question 1

define labour + the stages of labour

Answer 1

labour= presence of regular painful uterine contractions becoming progressively stronger/more frequent; accompanied by effacement(aka cervical ripening) is softening of cervix (relaxin released by placenta late stage of pregnancy causes this) + progressive dilation of cervix

24-48hrs prior to labour u have a show which is a bloody mucoid plug discharge (can be clear or bloody) usually amniotic sac ruptures but not always

stages of labour:
* latent phase (0-3cm) amniotic cavity still intact [encourage woman to keep mobile/walk around]
* active phase (4-7cm) established labour phase (amniotic sac/water has BROKEN) contractions very close together= 45-60secs
* transition phase (8-10cm dilation) = contractions are slightly further apart 60-90secs
* complete phase (10cm)

n.b. epidurals seem to slow dilation but depends when given

Question 2

shape of bony pelvis + how this affects position of foetal head during labour

Answer 2

so left occiput anterior (LOA) {bby head slightly side on} is most common; bby head is slightly off center in pelvis w back of head towards mother’s thigh

left occiput transverse= more painful/slower labour progression; this is when bby head points DIRECTLY to mother’s thigh {bby head completely side on}

Question 3

positive feedback mechanism of birthing (ferguson reflex)

Answer 3

• baby head stretches cervix and feeds back on posterior pituitary gland
  *pituitary secretes oxytocin into blood which travels to uterine muscle
  *oxytocin stimss uterine contraction + pushes bby down stretching cervix further
  *+ve feedback until bby is born.. then continues for a bit to prevent bloodclots and subsides (techinically what stops the +ve feedback is the birth of the bby)

Question 4

how wide is a fully dilated cervix?

Answer 4

cervix needs to dilate to 10cm so bby can pass through

Question 5

what is parturition?

Answer 5

parturition begins 6-4 weeks before end of gestation (body is preparing for childbirth) has uncoordinated contractions= Braxton Hicks contractions of myometrium .. women mistake them for labour and will be sent home as this isnt labour yet

ripening of cervix thanks to relaxin hormone secreted by placenta

Question 6

what hormones causes uterine musculature more contractile

Answer 6

progesterone, oxytocin, PGE2 and PGF2

PGE2 (prostaglandin E2) produces a biphasic effect with an initial contraction and a following relaxation, while PGF2α (prostaglandin F2 alpha) consistently stimulates myometrial contraction

Question 7

in parturition the
primary force is [] contractions
the secondary force is [] contractions

Answer 7

in parturition the
primary force is uterine myometrium contractions
the secondary force is abdominal muscle contractions

Question 8

in early stages hCG is maintaining corpus luteum, when does the corpus luteum degenerate and progesterone + oestrogen is just produced by placenta

Answer 8

week 12 will begin to degenerate and will fully degenerate by week 20

Question 9

how does progesterone vs oestrogen effect uterine contractility

Answer 9

progesterone inhibits uterine contractility during early stage of pregnancy= prevents early expulsion of baby

oestrogen increases uterine contractility+ increases the gap junctions between smooth msucle cells in myometrium making it easier to transmit wave of contractility through myometrium

so oestrogen continues to increase towards late stage pregnancy whereas level of progesterone stays about the same

Question 10

what is meant by multiparous vs nulliparous

Answer 10

nulliparous women (i.e., women having no previous births) are at higher risk for adverse birth outcomes than multiparous women (i.e., women having had at least one previous birth).

Question 11

define antenatal

Answer 11

antenatal= before birth occurs

Question 12

what cardiotocography indication in birthing woman means she need emergency C section

Answer 12

it the cardiotocography shows late decelerations

Late deceleration is defined as a visually apparent, gradual decrease in the fetal heart rate typically following the uterine contraction. The gradual decrease is defined as, from onset to nadir taking 30 seconds or more.

this wld mean vagal stimulation or myocardial depression from placental insufficiency. Late decelartions + bradycardia= EMERGENCY C SECTION REQUIRED

Question 13

what is fetal macrosomia/ macrosomic baby

Answer 13

fetal macrosomia= newborn who’s much larger than average

Question 14

what is cervical ripening; what hormones are released

Answer 14

cervical ripening= increased softening of cervix= by softening the collagen in the cervix- this may not go back to full pre-pregnancy state; cervix will shorten and flatten so bby head can go thru cervix into vagina

its comparable to inflammatory reaction, the following are released:
* prostaglandins (PGE2. PG2a)
* oestrogens
* progesterone + antiprogesterones
* relaxin (relaxes ectracellular matrix)
* inflammatory mediators
*nitric oxide
*apoptosis