Labour

DEFINITION
• Labour is defined as the process in
which the foetus and placenta are
expelled from the uterus via the birth
canal after a minimum period of 20
weeks.
• Normally, between 36 and 42 weeks of
gestation

SIGNS OF LABOUR
• Regular contractions felt in the abdomen or groin,
low in the back or in the legs
• Contraction tend to become longer, stronger and
closer together
• A ‘show’ of mucous discharge from the vagina,
which may be stained with blood.
• Braxton Hicks contractions
• Increased mucous discharge from the vagina
• Rupture of the membranes-the ‘bag of forewaters’
which surrounds the baby leaks or breaks. This is
less common, only about 10% of labours begin with
the waters leaking
• Some women experience constant minor backache,
with bouts of stronger back pain, during labour.

STAGES OF LABOUR
• Effacement is the shortening or thinning
of the cervix from a thickness of 5 cm (2
inches) before onset of labor to the
thickness of a piece of paper.
• Dilation is the opening of the cervix
from the diameter of a fingertip to
approximately 10 cm (4 inches).

• It is usually described as being from the onset of
regular contractions to full dilation of the cervix.
• Initially the cervix softens, shortens and begins to
dilate
• As contractions become longer, stronger and closer
together, dilation of the cervix continues. For most
women these contractions are painful and many
require some form of analgesia.
• Within the uterus, the uterine contractions exert an
intermittent upward pull on the lower segment of the
uterus and cervix, while at the same time applying
downward pressure on the foetus. This combination
opens the cervix, pushing the foetus against and
through it.
Stage 1

the cervix is fully dilated and there is no doubt that a
baby is about to be delivered. It has three phases:-
Cervical dilation phase: The cervix dilates from 0 to 3
cm (0 to 1 inch) and will almost completely efface.
Uterine contractions occur from the top down, causing
the cervix to open and pushing the fetus downward.
Middle phase. The cervix dilates from 4 to 7 cm (1 to 3
inches). Contractions are stronger and more regular.
Transition phase. The cervix dilates from 8 to 10 cm (3
to 4 inches) and dilation is complete. Uterine
contractions are very strong and close together.

Stage 2
• The second stage of labour is the time from full dilation
of the cervix until the birth of the baby.It involves
“pushing” and expulsion of the fetus
• As second stage progresses, the baby moves along
the birth canal. The contractions are usually stronger,
but may occur less frequently.
• The diaphragm and the abdominal muscles are
brought into action to help push the foetus out.
• Intra-abdominal pressure is the primary force expelling
the fetus; it is produced by voluntary contraction of the
abdominal muscles and diaphragm.
• Relaxation and stretching of the pelvic floor during
stage 2 are also necessary for successful vaginal
delivery.
• Uterine contractions may last as long as 90 seconds
during this stage.

1. Fetal descent. Position changes
(cardinal movements) by the fetus allow
it to pass through the pelvis and be
born.
i) Engagement. The greatest transverse
diameter of the fetal head passes
through the pelvic inlet (the superior
opening of the minor pelvis).
ii) Descent. Continued downward
progression of the fetus occurs.
iii) Flexion. The fetal chin is brought closer
to its thorax; this occurs when the
descending head meets resistance from
the walls and floor of the pelvis and the
cervix.
iv) Internal rotation. The fetus turns its
occiput toward the mother’s symphysis
pubis when the fetal head reaches the
level of the ischial spines.

Extension: The flexed fetal head
reaches the vulva; the fetus
extends its head, bringing the
base of the occiput in direct
contact with the inferior margin
of the maternal symphysis
pubis; this phase ends when the
fetal head is delivered.
External rotation: The fetus
rotates its occiput toward the
mother’s sacrum to allow the
fetal shoulders to pass through
the pelvis.
2. Expulsion: The fetal anterior
shoulder passes under the
symphysis pubis, and the rest
of the body follows.

Stage 3
• Placental stage (expulsion of the placenta).
• The third stage of labour is from the birth of the baby until
delivery of the placenta (after birth). It is usually the
shortest phase.
• After delivery, the uterus continues to contract and
shrink, causing the placenta to detach and be expelled.
– As the uterus decreases in size, the placenta
detaches from the uterine wall, blood vessels are
constricted, and bleeding slows. This can occur 5 to
30 minutes after the baby is delivered.
– A hematoma forms over the uterine placental site to
prevent further significant blood loss; mild bleeding
persists for 3 to 6 weeks after delivery.
• The uterus continues to contract and decrease in size for
3 to 6 weeks after delivery; the uterus always remains
slightly enlarged over its prepregnant size.

Duration of labour
• 12 – 14 hrs for 1st
stage, 1 hr for 2nd
stage
(primi)
• 6 – 10 hrs for 1st
stage, 30 min for 2nd
stage
(multi)

1st
Stage Management
• Energy conservation
• Monitoring of foetal & maternal well being
• Monitoring BP & HR (hourly)
• Emptying bladder 2 hrly
• Physically and mentally comfortable
• Periods of walking around
• Periods of sitting in chairs or beanbags
• Periods of resting, even dozing on a sofa or bed.
• Pleasant surroundings music and a warm bath or
shower may be helpful.
• Changes of position are important

2nd
Stage Management
• Avoid reclining (Vena Caval
syndrome)
• As crowning occurs, assistance may
be required for full distension
• Head extension facilitated & any cord
compression is looked for
• If delay occurs, mother is asked to
refrain from pushing
• May require nasal/ oral suction after
delivery

3rd
Stage Management
• Different schools of thought regarding
the time of clamping
• Immediate clamp: for rhesus –ve
mother
• Control haemorrhage
• Pressure applied to prevent uterus
from decending down
• Blood loss monitored

Interventions
• Relaxation
• Breathing
• Positioning
• Pain relieving agents

Ante-natal preparation
During pregnancy, relaxation helps the mother to cope with the
physical, psychological and emotional discomforts of pregnancy. It
induces rest and fatigue
During labour, relaxation is the single most important skill in the
control and conduct of labour. Between contractions , relaxation can
give the woman the rest she deserves.
Releasing tension-the art of relaxation: reciprocal relaxation
When a muscle contract relaxation is always produced in the
antagonist.
By using this principle it is possible to release tension in the stressed
muscle groups, generally those involved in the flexor response.
The orders to each joint are:
Move and feel the result of the movement
stop the movement
feel the result of the ‘letting go’. The feeling of ease(relaxation) is
registered in the appropriate area of the joint and skin.

Breathing
• WHY?
– Prevent hyperventilation
– Reduce apnoeic episodes
– Prevent respiratory alkalosis
• Goal:
– Controlled respiration (Consciously
altering rate & depth)

Breathing in 1st
Stage
• Deep & slow
• Pause between inspiration & expiration
• Altering with contractions
• TRANSITION PHASE: pushing is
delayed
– Sigh out softly ( ↓ urge to bear down)
– I won’t puuussshhh
– Puff puff and blow
– Reminder of coping strategies taught
antenatally

Breathing in 2nd
Stage
• Breathe in slowly → expire & push (5 –
10 sec) → maintain push while next
inspiration
• Breathe in, out, in → push with hold (<
6sec)
• 1 - 2 deep breathe at end of
contraction
• Avoid prolonged pushing

A useful teaching approach is:
•Ask the women how many times they think they breathe ou
in 1 minute – responses will vary greatly.
•Ask them to count each outward breath made during a
timed minute – again responses will vary greatly. This will
then reassure them with regard to the ‘normal’ range.
• Ask them to notice what happens when they breathe at
rest – cool air can be felt entering the nostrils, warm air
coming out.
•Ask them to focus on their own individual pattern of
breathing: a breath in – momentary tidal pause – a breath
out – and then a rest between breaths.
Ask them to feel where movement takes place as they
breathe; resting their fingers lightly on their ‘babies’, can
they feel a rise and fall of the abdomen? Explain how slow,
‘low’, or ‘deep’, calm ‘abdominal’ breathing has a soothing,
tension-releasing effect at times of stress.

Positions in 1st
Stage
• Tendency to lean forward to antevert
the uterus (Drive angle)
• Prone knee fall: uneven cervical
dilation (↓ anterior lip)

Positions in 2nd
Stage
• The prime considerations are the
baby’s safety, the mother’s comfort
and the position which enables her
to respond best to the bearing-down
reflex.
• Upright supported squatting
• Kneeling
• NOTE: head should never be
pushed down to chest

Position in 3rd
stage
• Supine (↓ chance of air embolism)
• Proper view of uterus
• Ease in application of cord traction
• The midwife may prefer the mother to
adopt a standing, kneeling or squatting
posture rather than lying back, to utilise
both gravity and intra-abdominal
pressure in helping the process

CAUSES OF PAIN DURING DIFFERENT STAGES OF LABOUR

Pain pathway
from the
uterus
A pain
gauge
site of
possible
back pain lower site
of the
abdomen
is the
most
common
site of
pain
S
T
A
G
E
1

Pain pathways.Nerves from the
cervix and pelvic floor pass to
sacral segments S2,S3 and S4
S
T
A
G
E
2

To show the changing pain zones of labour

Interventions for pain relief
• TENS
• Acupuncture
• Hypnosis
• Homeotherapy / aromotherapy
• Water births
• Inhalational / Epiduaral anaesthesia

TENS
• Burst TENS:
– Low frequency (<4Hz)
– Property of conventional & acupuncture like
TENS
• Brief TENS:
– High frequency (>100 HZ)
– Long pulse duration (>150 μs)
– Highest intensity as tolerable
– Used for short periods (10 – 15 min)
• Burst mode used all times, Brief mode
used only during intense pain

Placement of electrodes
• Rule out any contraindications
• Over relevant vertebral segments
– 1st
Stage: T11 – T12
– 2nd
Stage: T10 – L1
– Other pair: S2 – S4

Massage in labour
• Variable response
• Mechanism:
– Sensory stimulation ( pain gate)
– Deep sacral massage (release
endogenous opiates)
– Caring & non verbal support
• Massage to limbs
• Perineal massage

Massage Contd.
• Back massage:

Massage Contd.
• Abdomen massage:

Physiological and
Musculoskeletal changes
during pregnancy

“During pregnancy, multiple
physiologic adjustments are made to
maintain maternal hemostasis. In a
non-pregnant patient, many of these
alterations would be considered
pathological rather than
physiological.”

Effects of progesterone
1. Reduction in tone of smooth muscle:
(a) food may stay longer in the stomach; peristaltic activity is
reduced
(b) water absorption in the colon is increased.
(c) uterine and detrusor muscle tone is reduced
(e) dilatation of the ureters favoring urine stasis with
elongation to accommodate the increasing size of the
uterus; this may contribute to the likelihood of urinary tract
infections
(f) urethral tone reduced, which may result in stress
incontinence
(g) reduced tone in the smooth muscle of the blood vessel
walls leading to dilation of blood vessels, lowered diastolic
pressure.

2. Increase in temperature (0.5–1°C)
3.Development of the breasts’ alveolar and
glandular milk-producing cells.
4. Increased storage of fat.

Effects of oestrogens
1. Increase in growth of uterus and breast ducts.
2. Increasing levels of prolactin to prepare
breasts for lactation; oestrogens may assist
maternal calcium metabolism.
3. Increased water retention, may cause sodium
to be retained.

Effects of relaxin
1. Gradual replacement of collagen in target tissues (e.g. pelvic
joints, joint capsules, cervix) with a remodelled modified
form that has greater extensibility and pliability.
2. Inhibition of myometrial activity during pregnancy up to 28
weeks when women become aware of Braxton Hicks
contractions.
3. May have a role in the remarkable ability of the uterus to
distend and in the production of the necessary additional
supportive connective tissue for the growing muscle fibres.
4. Towards the end of pregnancy, rising levels of relaxin effect
softening of the collagenous content of the cervix (Verralls
1993).

Human chorionic gonadotrophin (hCG)
•Fertilization of the ovum prevents the regression of the
corpus luteum. Instead, the corpus luteum enlarges,
stimulated by the glycoprotein hormone, hCG, produced
by the trophoblast (the developing placenta).
• This hormone can be detected in maternal blood 6-9
days after conception and may be detectable in the urine
1-2 days later.
• Its detection in the urine provides a highly sensitive
and specific test for the diagnosis of pregnancy. The
secretion of β-hCG begins to fall by 10-12 weeks,
although it remains detectable in the urine throughout
pregnancy.

• HCG is considered to play a role in the early
pregnancy discomforts like Morning Sickness and
fatigue.
• HCG in the early days of pregnancy helps to support
the pregnancy by stimulating the ovaries to produce
progesterone, resulting in the cessation of the
menstrual cycle during pregnancy.

CARDIAC OUTPUT ↑ during pregnancy ≈
1.51/min.
•Changes in cardiac output(Stroke Volume X
Heart rate) includes
40% increase in first trimester, persisting
throughout pregnancy.
Stroke volume is increased by 30%.
Heart rate is increased by 15 beats per
minute.
•The increased output is directed to the uterus,
kidneys, and the gastrointestinal tract.
•Cardiac output increases during labour and
returns to normal levels by two weeks post
partum.

• When the pregnant women lies supine
the cardiac output is decreased
because of uterine compression of the
inferior vena cava and is known as
supine hypotension or vana caval
syndrome.
• May relieve by side lying.
• In right side lying COP increase by
10%
• In left side lying COP Increase by
20%. So most preferred position.

BLOOD PRESSURE
•Little change in systolic BP
•Decrease in Diastolic BP in mid
pregnancy, which returns to normal in
late pregnancy
•Normal value of BP for pregnancy <
140/90
•Pregnancy Induced Hypertension
(PIH)diagnosed when
– SBP >30mmhg
– DBP > 15mmhg

• Venous blood pressure
• Rise in venous BP in LL
• Due to hydrostatic pressure &
mechanical pressure in pelvis.
• Resulting into LL oedema,
varicosities, & distension of the
veins.

• Blood Volume:
• Plasma volume increases by 50% while
red cell mass increases by 20-30%,
resulting in a total blood volume increase
of 40% from 4.0 litres to 5.5 litres.
• The effective haemodilution is known as
physiological anemia.
• This increase in blood volume allows the
women to withstand the average blood
loss at delivery of 500 ml without adverse
effects.

• Peripheral vasodilation:
• This occurs because of progesterone which
reduces the effect of angiotensin in blood.
• Women`s with Raynaud`s diseases may
experience relief from the painful condition.
• Nasal mucous membrane may be congested which
may results in epistaxis(Nose Bleeding),palmar
erthyema, vascular spiders and hemangioma may
occur on the skin.
• Peripheral Resistance:
• A 20% decrease occurs as a result of increased
cardiac output and unaltered blood pressure levels.
• Blood flow increases especially in the hands and
feet, causing sensation of warmth and a partial
immunity to cold.

Heart
•Elevated diaphragm – raises & rotates the heart to lateral
& higher ( shift of apex)
•Electrocardiograph(ECG) changes may occur which
mimic ischemic heart diseases.
•Increased tendency to supraventricular tachycardia, atrial
or ventricular systole disturbances, rhythm disturbances.
Myocardial Contractility:
•This increases throughout pregnancy due to lengthening
of the muscle fibers, causing mild ventricular hypertrophy.
•Increased blood volume and venous return results in an
increased diameter of the left atrium.

RESPIRATORY SYSTEM
• There is increased congestion in lung
capillaries + Increased respiratory center
sensitivity
• Also basal O2 consumption increases to
30-40ml/min.
• Minute vol. ventilation increases to 40%.
• Diaphragm movement is restricted
Hyperventilation & shortness of breath

• displace the diaphragm upwards,
often by 4 cm or more.
• respiratory excursion is limited at the
lung bases and greater movement is
observed in the mid-costal and apical
regions, and women frequently
experience considerable
breathlessness on even modest
exertion towards the end of the
pregnancy.

• The immune system is slightly depressed but it is still
capable of developing antibodies.
• Pregnant women are more prone to develop
diseases such as pneumococcal pneumonia,
influenza or poliomyelitis.
• They may be more predisposed to reactivation of
latent viruses e.g. cytomegalovirus or herpes virus.
• The baby is protected against trans placental and
post natal infections by passive antibodies from six
weeks of pregnancy to nine months of age. As a
foetus, the baby receives immunoglobulin-G(IgG) by
placental transfer, gaining passive immunity.
• Of the 4 immunoglobulins, IgG is the only one which
can crosses the placenta.

• Morning sickness, nausea and /or Vomitting occur
most commonly in early pregnancy but may occur
throughout pregnancy in some women.
• Excessive vomiting in pregnancy(hyperemesis
gravidarum) affects a small percentage of women and
may requires hospital administration.
• Vomiting is associated with human Chorionic trophin
(HCG) which rises in early trimester and may cause
vomiting.
• Odours and some foods are the causes of vomiting in
some women.
• Appetite increases in early pregnancy and may persist
throughout the pregnancy. The upward pressure of the
foetus on the stomach reduces the capacity for large
amounts of food in late pregnancy, which may be
compensated for by snacking more frequently on
smaller amounts of food.

• Occasionally pregnant women reports abnormal
carvings for substances such as coal and
chalk(pica). More commonly are the cravings for the
foods which are salted and spiced rather than
sweet.
• The reduced speed of oesophageal peristalsis,
• a hormonally mediated slackness of the cardiac
sphincter,
• displacement of the stomach
• an increased intra-abdominal pressure as
pregnancy progresses
All favour the gastric reflux or ‘heartburn’ of which so
many women complain

WEIGHT GAIN IN
PREGNANCY
• First 20 wks of pregnancy – 0-2kg
• Up to 30wks – 1kg/month
• b/w 30-40 wks - 1kg/fortnight
• Women can gain from >5-<20 kg.
• <5kg wt gain is related to –
INTRAUTERINE GROWTH
RETARDATION.

• Pigmentation –
 darkening of the areola on the breasts.
 Linea nigra (vertical stripe in abdominal midline)
 Chloasma ( increased facial pigmentation) or mask of
pregnancy
 Striae gravidum ( stretch marks),
 Occurs in abdomen, breasts, thighs, buttocks.
 Caused by changes in the elastic fibers & collagen in
the dermis.
 The dermis ruptures & overstretches the epidermis
resulting into scarring.

• This marks are permanent ,but changes from blue/red
wide marks to smaller silvery lines over times.
• Note: Massage, creams, oils and lotions will not
prevent or remove the scars, but may helps to
decrease the tight dry feelings of the stretched skin.
Hair Loss:
• After the birth of the baby, the mother may notices
increased hair loss and it is associated with marked
reduction in hair loss ,as a result of an increased
growth phase of the hair follicles.
• Hair Growth and loss usually return to pre pregnancy
rates by 20 weeks post partum

CHANGES IN BREASTS
• Early pregnancy – tenderness & fullness b/c of
hormone relaxin, progesterone & oestrogen.
• Around 12 wks – begin to make1st
milk (colostrum)
• Breasts wt increases by 500-800gm.
• Blood supply increases.
• Nutritionally mother needed an extra 2000kj/day to
fulfill the demands of breast feeding.
• Mature milk production commences 24- 96hrs post
partum.
• Stimulation of nipple by frequent feeding in 1st
24 hrs
causes early changeover from colostrum to mature
milk by stimulating prolactin production
• Colostrum is rich in protein & antibodies, assists in
providing immunity, particularly to gastroentritis in
baby.

• Progesteron effects smooth muscle causes
dilatation of URETERS.
• URETERS also elongated to accommodate with
increasing size of uterus.
• Also URETERS get compressed by uterus in late
pregnancy
So slowing of urine flow & increase frequency.
• Throughout pregnancy there is a increase in blood
supply to the urinary tract in order to cope with the
additional demands of the foetus for waste disposal.
• There is an increase in size and weight of the
kidneys, and dilation of the renal pelvis.

Uterus:
•In the non pregnant women, the uterus is approximately
the size of a pear, weighs around 60 grams and can hold 6
milliliters.
•By 40 weeks of pregnancy, the uterus weighs 1000 grams
and can holds 5000 milliliters.
– The contractile protein actin-mysin is responsible for
most of the increase in muscle fibers. Later in
pregnancy, the fibers also stretches, causing thinning
of the uterine wall, especially in the lower segments.
•As pregnancy progress, the uterus contractions becomes
stronger under the influence of the hormone
prostaglandins which is being released from the decidua.
These contractions are also called as Braxton Hicks.
•The sensitivity of the uterus to oxytocin increases in
pregnancy by up-to 100 times.

Cervix:
•The cervix enlarges because of increasing
vascularity and softens under the influence of
oestrogen and progesterone as the pregnancy
progress.
Vagina:
•The vagina changes in colour and firmness
,similar to the cervix.

• Mood lability, anxiety, insomnia,
nightmares, food fads and aversions,
slight reductions in cognitive ability and
amnesia
• Water retention quite frequently causes
unusual pressure on nerves, particularly
those passing through canals formed of
inelastic material like bone and fibrous
tissue (e.g. the carpal tunnel), with
resulting neuropraxia.

• Relaxin, progesterone, oestrogen , cortisol
• Increases jt laxity & range
• More in multigravidae than primigravidae
• Takes 3-4 mnths for body to return
prepregnant state.
• Postural changes due to – increase
abdominal size thoracic & lumber
curves increases LBP
• increase abdominal size COG shifts
anteriorly. Waddling gait.

• The increased body weight must result in more
pressure through the spine, and increased
torsional strains on joints. Women become
clumsier and are inclined to trap and fall.
• In the third trimester there is increased water
retention, which may result in a varying degree
of oedema of ankles and feet in most women,
reducing joint range.

• Factors related to the development back pain
during pregnancy
• Symptoms Proposed causative factors
• LBP 1.weight gain during pregnancy
2.Rapid postural changes
3.Vascular effects
4.Previous back pain experienced
during menstruation
5.Back pain in previous
pregnancies
6.Repetitive lifting/bending
• S.I pain 1.pelvic insufficiency due to

Major regions associated with this pain -
• Pain above the lumbar region only.
• Pain in the lumbar region with or
without radiation to one or both legs.
• Pain over the S.I area sometimes with
radiation to the side
• Pain in the symphysis pubis was
apparent in all groups.

• Diastasis recti – muscle of abdominal wall
adapt to increasing foetal growth &
stretching of muscle fiber
• Widening & splitting of linea alba &
softening of aponeurosis & fibrous sheath.

Labour

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