10 Flashcards
(44 cards)
1
Q
When do pregnancies end?
A
With the expulsion of the products of conception (i.e. fetus and placenta)
2
Q
What is labour?
A
- process where fetus, placenta and membranes are expelled through birth canal
- when the expulsion of products occurs after 24 weeks of gestation
- normal labour is spontaneous in onset at term (37-42 weeks)
See physiological labour slide 7-8
3
Q
If expulsion of placenta and fetus occurs before 24 weeks of gestation, what is it called?
A
- spontaneous abortion (miscarriage)
- parturition
See physiological labour slide 2
4
Q
What is the term for labour that occurs before the 37th week of gestation?
A
-premature or pre-term labour
5
Q
What environment is the most conducive to a normal physiological birth?
A
- calm, private, oxygenated
- little need for sterility
- need high levels for oxytocin for birth process and for feeding baby
- birth process is a continuum from in-utero to ex-utero for baby
- no break in concentration
See physiological labour slide 3
6
Q
What are the main processes during the first stage of labour?
A
- creation of a birth canal
- release of the structures which normally retain the fetus in utero
- enlargement and realignment of the cervix and vagina
7
Q
What is the main process during the second stage of labour?
A
-expulsion of the fetus
8
Q
What is the main process of the third stage of labour?
A
-expulsion of the placenta and changes to minimize blood loss from the mother
9
Q
Describe the uterine muscle fibres
A
- longitudinal muscles: push baby out
- circular muscles: around Fallopian tubes and cervical end for dilation
- oblique muscles that go across the uterus and contracts to cut blood supply of placenta
See physiological labour slide 4-5
10
Q
What occurs during the first stage of labour?
A
The fetus, placental membranes and uterus increase dramatically in size during gestation. The uterus first becomes palpable at around 12 weeks of gestation, by 20 weeks it has reached the level of the umbilicus, by 36 Pregnancies end with the expulsion of the products of conception; i.e. weeks it reaches the xiphisternum.
See physiological labour slide 9-10
11
Q
What is the “lie” of the fetus?
A
- describes the relationship of the long axis of the fetus to the long axis of the uterus
- commonest lie is longitudinal, with the head/buttocks posterior
- fetus normally has a flexed attitude
12
Q
What is the “presentation” of the fetus?
A
- describes which part of fetus is adjacent to the pelvic inlet
- if baby lies longitudinally the presenting part may be the head or the breech
13
Q
Describe what occurs during pre-labour
A
- lightening occurs 2-3 weeks prior to to the onset of labour
- expansion of the lower segment
- fetal head engages
- symphysis pubic widens, sarcomere-iliac joints relax
- pelvic floor relaxes
- increased vaginal secretions
- frequency of micturition
- Braxton hicks contractions
- taking up of the cervix
See physiological labour slide 11-12
14
Q
In what position does the baby usually lie in the fetus?
A
- commonly lies longitudinally in cephalon presentation
- well flexed so that the vertex presents to the pelvic inlet
- birth canal needs to have a diameter of about 10cm for fetus to pass through
15
Q
How is the birth canal dilated through cervical softening?
A
-The cervix has a high connective tissue content made up of collagen fibres embedded in a proteoglycan matrix.
-Ripening involves a marked reduction in collagen and marked increase in glycosaminoglycans (GAGs), which decrease the aggregation of collagen fibres. In consequence collagen bundles ‘loosen’.
-There is also influx of inflammatory cells, and increase in nitric oxide output. All of these
changes are triggered by prostaglandins, namely E2 and F2a
16
Q
How does the uterine smooth muscle help in dilation of birth canal?
A
- The myometrium is made up of bundles of smooth muscle cells.
- During pregnancy, the myometrium gets much thicker due primarily to increased cell size (10 fold) and glycogen deposition.
- An intracellular apparatus containing actin and myosin, triggered by a rise in intracellular calcium concentration, generates force.
- The rise in calcium concentration is produced by action potentials in the cell membrane.
- Action potentials spread from cell to cell via specialised gap functions, allowing co-ordinated contractions to spread over the myometrium.
- Some smooth muscle cells are capable of spontaneous depolarization and action potential generation, and so can act as ‘pacemakers’.
- The myometrium is therefore always spontaneously motile. In early pregnancy contractions may occur every 30 minutes or so, but are of low amplitude.
- As pregnancy continues, the frequency falls, with some increase in amplitude, producing noticeable ‘Braxton-Hicks’ contractions. -None of these contractions are normally forceful enough to have any effect on the fetus.
See physiological labour slide 14
17
Q
What are the two main hormones implicating the sudden increase and force of contractions during labour?
A
- prostaglandins: enhances the release of calcium from intracellular stores
- oxytocin: secreted from posterior pituitary under the control of neurons in the hypothalamus; acts by lowering the threshold for triggering action potentials
See physiological labour slide 15-23
18
Q
What is the Ferguson Reflex?
A
- increases as contractions increase and helps to increase oxytocin secretion
- Sensory receptors in the cervix and vagina are stimulated by contractions; excitation passes via afferent nerves to the hypothalamus, promoting massive oxytocin release.
- This ‘positive feedback’ makes contractions more forceful and frequent.
19
Q
What is brachystasis?
A
- At each contraction muscle fibres shorten, but do not relax fully.
- The uterus, particularly the fundal region therefore shortens progressively.
- This pushes the presenting part into the birth canal and stretches the cervix over it.
- Descent of the presenting part (commonly the fetal head) therefore occurs progressively during labour, until it engages in the pelvis.
See physiological labour slide 29, 34-35
20
Q
How is labour initiated?
A
-evidence suggested it is initiated by prostaglandins and oxytocin production which is triggered by fall in progesterone and oestrogen levels
21
Q
Describe the second stage of labour
A
-starts when cervical dilation reaches 10cm
-lasts up to 1 hour in the multiparous woman up to 2 hours in priming Ravi day
1. The descended head flexes as it meets the pelvic floor, reducing
the diameter of presentation.
2. There is then internal rotation.
3. The sharply flexed head descends to the vulva, so stretching the vagina and perineum.
4. The head is then delivered (‘crowning’), and as it emerges it rotates back to its original position and extends.
5. The shoulders then rotate followed by the head, and the
shoulders deliver, followed rapidly by the rest of the fetus.
See physiological labour slide 48-71
22
Q
What complications can happen to the baby’s shoulder during fetal delivery?
A
-shoulder dystocia
23
Q
Describe the third stage of labour
A
- With the fetus removed there is a powerful uterine contraction, which separates the placenta, positioning it into the upper part of the vagina or lower uterine segment.
- The placenta and membranes are then expelled, normally within about 10 minutes.
- This completes the third stage of labour.
- This contraction of the uterus also compresses blood vessels and reduces bleeding. It is normally enhanced by administration of an oxytocic drug.
See physiological labour slide 72-84
24
Q
What is the APGAR score?
A
- assesses fetal wellbeing soon after delivery
- generates a score from 1-10, higher the number the healthier the baby
25
In terms of the elements of labour, what is the powers, the passage, and the passenger?
The powers
-Delivery of the fetus is dependent upon contraction of the myometrium, which has undergone considerable hypertrophy and hyperplasia during pregnancy. Contraction and retraction of the multidirectional smooth muscle fibres causes progressive shortening, particularly in the fundus of the uterus. Uterine contractions can be assessed in terms of frequency, amplitude and duration.
THe passage
-The passage is formed by the bony pelvis and soft tissues. The pelvic inlet is shorter in the anterior - posterior plane (obstetric conjugate, 10.5cm). Between the pelvic inlet and outlet, the mid-cavity is circular (12cm diameter). The pelvic outlet is narrowest usually mediolaterally (11cm). The fetus flexes, extends and rotates as it passes through the birth canal. Resistance of the soft tissue can slow labour.
The passenger
-The size and presentation of the fetus is critical in labour. The orientation of the head of the fetus when entering the pelvis (in a cephalic delivery) is variable and as such the head diameter of the fetus is different in differing positions. However, moulding of the fetal cranium may occur since cranial sutures have not yet fused.
26
What is the post-partum period?
- period from delivery of the placenta to week 6 post natal
- period when the changes that occurred as a result of pregnancy revert to pre-pregnancy state
- period of great changes/modifications in lifestyle, psychology, activities, relationships, responsibility, etc.
- period of step-down medical input if any required during pregnancy
- potential for problems to occur
- period continued optimal management of any pre-existing medical conditions
27
How is the new mum looked after, post-delivery?
- post-natal care
- initially provided at home by comity midwife, where they provide advice on contraception, breastfeeding and checking episiotomy healing
- midwife visits for a period of not less than 10 days post delivery up to as long as necessary up to 28 days post delivery
- after that a health visitor will then take over
28
What happens during a post-natal examination?
- mothers encouraged to attend specific clinics with their baby once a week until 6 weeks of age
- assess mother-infant interaction
- assess the woman’s mental and physical health as well as feeding and behaviour of the baby
- direct questions about urinary, bowel and sexual function as well as incontinence
- dyspareunia or anxiety about sexual intercourse are issues that many women will not discuss VOLuNTARILY
- BP, urinalysis and a general, breast, abd and pelvic/perineal as required
- discuss adjustment to parenthood and any anxieties she may have
- cervical smear if required
See post-partum slide 6-7
29
What anatomical and physiological changes occur during post-partum?
- characterized by low-oestrogen levels
- female body reverting back to the pre-pregnancy state
- lower genital tract
- reduction in size of vulva, vagina and cervix
- poor lubrication of vagina
- transformation zone of the cervix withdraws into the endocervix
- internal os is closed
- bleeding: initial heavy flow (lochia rubra) but gradually reduces
- changes from red-brown/red-pink-heavy white (lochia alba)
- passage of clots NOT NoRMAL, except for the one passed on day 3 or 4
- endometrium regulates
- if no lactation, new endometrium by week 3, 1st period due by week 6
- if lactation, ovarian activity suppressed, therefore period delayed by several months
- skeletal muscle: devarication of the recta, resolves depending on pre-pregnancy laxity, parity, level of physical activity
- skeleton: ligament laxity resolves
- CVS function: increased PR (by 15bpm) at term and increased CO reverses by week 6
See post-partum slide 8-10
30
How is haematology affected during the post-part up period?
- Hb: reduction in plasma volume and increase in Hb level
- white cell count: very high levels in immediate post-partum and pregnancy-related changes are still present 6- weeks after delivery
- platelet count: in normal delivery platelet count rises rapidly to non-pregnant values but after operative or c-section, delivery may rise to high levels
- serum ferritin, transferrin and iron: levels are significantly decrease but will return to normal levels by 5-8 weeks postpartum irrespective of iron supplementation
See post-partum slide 11
31
How is endocrinology affected during postpartum period?
- gamma glutaryl transferase, AST, ALT: levels all increase after delivery
- plasma levels of cholesterol and triglycerides: levels are grossly elevated and only fall slowly to normal non-pregnant levels over many months
- prolactin levels: remains elevated in lactating women postpartum but fall into non-pregnant range by 2-3 weeks postpartum in non-lactating women
- thyroxine levels: thyroid function should return to the non-pregnant state by 6 weeks postpartum
See post-partum slide 12
32
Describe the psychology during postpartum period
- positive feelings in the puerperium such as satisfaction, increased closeness to partner, mother, baby, protectiveness towards baby
- negative feelings such as dissatisfaction, anxiety and rejection about baby, fears of harming baby, overwhelming responsibility
See post-partum slide 13-15
33
How does lactation occur?
- progesterone, oestrogen, prolactin, growth hormone and adrenal steroids cause hypertrophy in breast
- formation of new alveolae by budding from the milk ducts, with proliferation of milk-collecting ducts
- although high levels of lactose nic hormones (prolactin and placental lactogen), only minimal amounts of milk formed since oestrogen and progesterone inhibit its effects
- prolactin released by the action of suckling at a nipple and is only used for preparation of the breast
- oxytocin is responsible for release of breast milk as it contracts the myoepithelial cells to contract and expel milk into the milk-collecting ducts
- milk-collecting ducts have longitudinal muscle cells which dilate when stimulated and improve the free flow of milk towards the nipple
- milk secretion dependent on adequate emptying of the secreting glands since accumulation of milk will cause distension and atrophy of the glandular epithelium
- “let down” reflex since oxytocin is released in a pulsatile manner
See post-partum slide 16-19 and wkbook
34
What are the components of breast milk?
- low salt content
- high energy content
- less protein
- more lactose
- more digestible by human baby
- foremilk: higher water content
- hind milk: higher in fats and iron
See post-partum slide 20
35
What are the functions of breast milk?
- protection form infection
- lactoferrin in breast milk binds iron
- bacteriocidal enzymes are present
- specific immunoglobulins are present and are formed by the mother’s Peyer’s patches
- IGA formed in this way
See post-partum slide 21-22
36
When can a woman formula feed?
- during severe maternal illness
- maternal HIV
- mothers on meds that are contraindicated when breastfeeding
See post-partum slide 23
37
What breast problems can occur postpartum?
- nipple sensitivity and pain
- engorgement
- mastitis
- breast abscess
- breast lumps- benign or malignant
- breast lump always must be investigated
- self-examination
- if malignant, must be treated
See post-partum slide 24
38
What early problems of puerperium can occur?
- haemorrhage: primary or secondary
- retained placenta: infection, bleeding
- uterine inversion: obstetric emergency
- perineal trauma: bruises/tears, sequelae
- maternal collapse/cardiac arrest: amniotic fluid embolism, hypoglycaemia, hypotension
- thromboembolic disease: risk factors are surgery, obesity, just having a baby, immobility
- Pyrexia/sepsis: genital tract, urinary tract or lactation ducts
- mental health problem
See post-partum slide 25
39
What is postpartum haemorrhage?
- obstetric emergency
- can cause major blood loss and CVS shock
- secondary PPH presents as prolonged bleeding once mom has returned home
- is typically caused by infection and/or retained products of conception
- remember as 4 T’s: Tone, tissue, thrombin, trauma
40
What are the postnatal blues?
- common afteder delivery
- refers to altered mood experienced due to hormonal changes
- mom typically feels more tearful or anxious
- baby blues usually peaks at day 4 or 5
- managed by reassurance and support
See post-partum slide 26
41
What is postpartum depression
- usually occurs within 4 weeks of delivery with similarly symptoms to depression
- moms may feel reluctant to share so it is important to ask
- management depends on the severity of the condition
See post-partum slide 26
42
What is puerperal psychosis?
- usually occurs within 4 weeks of delivery
- rare but is a psychiatric emergency
- usually occurs in women with pre-existing mental illness
- severe symptoms: anxiety, mania, paranoid thoughts and delusions
- suicide risk
- management: specialist care, primarily pharmacological
See post-partum slide 27-31
43
What is puerperal mastitis?
- condition where milk accumulation in breast can lead to inflammation with or without infection
- typically occurs if mother doesn’t breastfeed with both breast and so milk can build up in lactiferous ducts of the unused breast
- if infection present it is usually caused by staph aureus and can lead to abscess formation
- treatment: continue feeding and increase the frequency on the affected side
44
How is sexuality and sexual function affected during the postpartum period?
- important to introduce contraception in post-natal period since family planning following childbirth helps reduce maternal and infant deaths
- timing of the return of fertility after childbirth is unpredictable and women can get pregnant before the return of menstruation
See post-partum slide 32-34
