2. Definition of Obstructed labour
(Dystocia)
• Definition:
The word dystocia is derived from the Greek root ”Tókos”
which means ”childbirth” thus dystocia means
difficult labour.
• The World Health Organization (WHO) defines
obstructed labour as the labour in which “the presenting
part of the fetus cannot progress into the birth canal,
despite strong uterine contractions .”
3. Epidemiology of Dystocia
• In the United States, 8-11% of all deliveries are complicated by
an abnormal first stage of labor. Dystocia accounts for 12% of
all deliveries in women without a previous CS history, and
causes 60% of cesarean deliveries.
• Obstructed labour accounts for one fifth of all maternal
mortality and morbidity causes in developing countries.
• In the years of 1990 and 2010, this condition accounted for
19,000 and 11,000 deaths respectively.
• Literature reviews suggests that in many countries maternal
mortality due to dystocia is as prevalent today as it was 30
years ago.
4. Epidemiology continued
• A community based retrospective study
conducted in Ghana found that out of 324
maternal deaths, 26% was contributed to
obstructed labour.
• Another study made in Guinea-Bissau, using
verbal autopsies, found that 19% out of 350
maternal deaths was due to obstructed labour.
5. Epidemiology continued
• In Uganda a study of 2006 found that 22% of all
maternal deaths was due to obstructed labour
• Globally it accounts for 8% of all maternal
deaths annually.
• The WHO has set a goal to reduce the incidence
of obstructed labour related maternal mortality
by the year 2015 with 75%
6. Predisposing Factors to Dystocia
• Maternal causes:
- Rickets during growth causing osteomalacia leading to
contracted pelvis
- Polio like illness causing bone deformities affecting the
structure of the hip
- Short stature (<150 cm)
- Female genital mutilation
- A serious RTA damaging normal pelvic anatomy
- Vaginal stenosis or tumour
- Rigid perineum
- Pelvic tumour
7. Predisposing Factors to Dystocia
• Fetal causes:
- Macrosomia, either generalised or localised
- Large fetal head (Hydrocephalus) or other
congenital fetal anomalies
- Locked or conjoined twins
- Non longitudinal fetal lie, eg transverse or
oblique
- Erect position of fetal head instead of flexed
8. Pathophysiology of Dystocia
• Normal uterine contraction physiology:
• The purpose of uterine contractions is to deliver the fetus and the
placenta, and thus does not mind any obstructive event.
• The whole process of delivery comprises a series of contractions
occuring in a regular pattern. Each contraction lasts for about 60
seconds and can reach a pressure of 50 mmHg.
• Every contraction requires a huge amount of ATP to allow the
smooth muscles of the uterine cavity to contract.
• The whole process of muscle contraction can be summerized in this
process called the ”cross-bridge cycle”:
- Depolarisation signal Calcium influx into the cells (due to ion
channel opening) Activation of Myosin Light Chain Kinase
(Which phosporylates myosin) Muscle contraction (due to cross-
briding of actin with myosin)
9. Pathophysiology of Dystocia
• The cross-bridge cycle consumes ATP, and the hydrolysis
of this constituent will produce acids.
• The maternal body of a healthy pregnant can sustain
contracting for house to deliver the fetus. But when the
hours becomes days, this will lead to depletion of the
metabolic reserves, and thus ATP levels will become low.
• There will be in lactic acid production (mainly due to
the inability to excrete protons) this will ultimately
lead to diminished uterine contractility Obstructed
labour!
10. Clinical Features of Dystocia
The patient has been labouring for more than 12 hours without any
progress to delivery.
11. Clinical Featires of Dystocia
-The patient is in distress and maybe exhausted
-The Urinary bladder might be full but inable to evacuate its
contents
-The patient is dehydrated, and her urine might be blood
stained.
12. Clinical Features of Dystocia
The membranes are ruptured and amniotic fluid
might be stained with meconium
13. Clinical Features of Dystocia
Palpation of gravid abdomen may reveal unusal
shapes and fetal parts can not be felt. There might
be a high retration ring (Bandl’s ring)
14. Clinical Features of Dystocia
The FSH are either absent or there might be fetal
distress with accelerations and decelerations.
15. Evaluation of a Woman with Dystocia
• Hours of labour progress and vaginal
examination?
• Bleeding? Liquor colour?
• Fetal activity?
• Uterine consistency?
• Any tetanic contractions?
16. Evluation of a Woman with Dystocia
• Examination:
- There is usually an edematous and swollen vulva
- The cervix is fully dilated to palpation
- The presenting fetal part may be moulded or
obstructed in the pelvis
- Check for the position of the head and colour of
the liquor
- The vagina is dry and there may be purulent
discharge
17. Managment of Dystocia
• Fluid replacement as the patient is most likely to
be dehydrated
• Plot every single change regarding the delivery
on a partogram
• Administer tocolytics to prevent contractions
that may render the condition worse
• Take CBC, and cross matching for eventual C/S
18. Managment of Dystocia
• Important essential steps to be taken:
- Broad spectrum antibiotic administration
- Vital signs check every 15 minutes
- Catheterization to determine the amount of
urine output and colour
19. Managment of Dystocia
• Obstetric interventions:
- Attempting vaginal delivery: Done when head is low
or the fetus is dead, usually by forceps extraction.
- Administration of oxytocin, unless there are strong
uterine contractions and any enhancement can
affect the fetal life.
- Cesarean section: Done for alive fetus with
impaction and is usually the managment of choice
for obstructed labour in general
- The remaining third stage of labour should be aided
actively
22. Complications of Dystocia
• Fetal complications:
- Fetal asphyxia
- Fetal death
- Congenital infections such as pneumonia and
septicemia
- Intracranial hemorrhage due to excessive head
moulding
- Acidosis
23. Prevention of Dystocia
• Community education about this phenomenon
• Proper ANC visits to ensure fetal and maternal
wellbeing during the progress of pregnancy and
to assess for any riskfactor to obstructed labour
• Assessment of the risk factors: eg. pelvic outlet
structure or fetal size