Obstetrics Simplified - Diaa
It is a state of inadequate oxygenation and inadequate elimination of
- Maternal causes:
- Anoxia due to:
- Cardiac failure.
- Pulmonary diseases.
- Anaesthetic agents causing hypotension.
- Severe anaemia.
- Eclamptic fit.
- Placental causes:
- Placental compression as in:
- Tonically contracted uterus.
- Prolonged labour after rupture of membranes.
- The old method to control bleeding from a placenta
- Placental insufficiency: due to acute causes as separation or
- Umbilical cord:
- True knots.
- Tight coils around the neck.
- Prolapsed cord leading to its compression and vasospasm
of its vessels.
- Compression by the forceps’ blades.
- Rupture of vasa praevia.
- Haematoma of the cord.
- Avulsion of the cord.
- Foetal causes:
- Cerebral oedema and ischaemia leading to decreased blood supply
to the respiratory centre in the medulla. This may result from:
- Intracranial haemorrhage.
- Depressed skull fracture.
Diagnosis = Signs of Foetal Distress
- Foetal heart rate changes: in the form of;
- Tachycardia: > 160 beats / min. due to sympathetic stimulation
caused by mild hypoxia.
- Bradycardia: < 100 beats / min due to vagal stimulation
caused by moderate hypoxia.
- Cardiac arrhythmia (irregular FHR): due to severe hypoxia.
It is the most dangerous one.
- Late deceleration.
- Loss of beat - to - beat variation.
- Meconium stained amniotic fluid:
Asphyxia causes increased intestinal movement and relaxation of the foetal
anal sphincter with passage of the intestinal contents
Grades of meconium and its management:
||A good volume of liquor, lightly
stained with meconium.
||Review the clinical presentation
e.g. FHR. Stop oxytocin + left lateral position.
||A reasonable volume of liquor with
a heavy suspension of meconium.
||Foetal blood sample is indicated.
||Thick undiluted meconium resembles
||Caesarean section unless easy vaginal
delivery is imminent.
N.B. The fresh thick dark brown meconium that is seen on the examining
fingers in breech presentation is not an indicator of foetal distress.
- Foetal acidosis: scalp blood pH < 7.2.
- Foetal movements: increased in early distress.
- Cord pulsation: is weak, if cord is prolapsed.
- Stop oxytocin drip: if it is in use.
- Left lateral position of the mother: to relieve aorto-caval
compression → improves venous return
→ improves cardiac output
→ improves uteroplacental blood flow.
- Oxygen: is given by mask to the mother in a rate of 6 litres
/ min. increases the O2 supply to the foetus.
- Immediate delivery:
- is indicated if the foetal distress is not improved by the conservative
methods. This is achieved by:
- Vacuum extraction, forceps delivery or breech extraction:
if the cervix is fully dilated and vaginal delivery is amenable.
- Caesarean section: if rapid vaginal delivery is not amenable.
- Causes in the respiratory centre:
- Paralysis: due to cerebral haemorrhage.
- Depression: by drugs as morphine, pethidine or anaesthesia.
- (Causes in the lungs:
- Congenital atelectasis.
- Respiratory distress syndrome: due to deficient lung surfactant.
- Causes in the respiratory passages:
- Obstruction by: meconium, liquor, blood, mucus.
- Causes in the respiratory muscles:
- Congenital debility.
- Weakness in prematures.
It depends upon the type (stage) of asphyxia:
||Mild (early stage)
||Severe (late stage)
|Colour of skin
||May be present
||Strong, 80-120/ min
||Weak, <80 /min
||A degree of muscle tone
||Good, easy resuscitation
||Bad, difficult resuscitation.
Apgar score: It is a clinical assessment of the newborn’s condition,
its need for resuscitation and the response to it. It is done at 1 and 5
minutes from delivery.
||Some limb flexion
|Reflex (Response to nasal
||Cough or sneeze
||Blue or pale
||Body pink, limbs blue
The score at 1 minute determine the need for resuscitation:
||Only nasopharyngeal aspiration.
||Position the baby + O2 mask.
+ cardiac massage + drugs.
The 5 minutes-score is an indicator of future CNS efficiency.
Prophylaxis of Asphyxia Neonatorum
Proper antenatal care.
Proper intranatal monitoring.
No morphia 4 hours or pethidine 2 hours before delivery.
Minimise the foetal exposure to anaesthesia during
labour and ensure adequate oxygenation with it.
Episiotomy in proper time.
Avoid birth trauma.
Vitamin K 10 mg to the mother during labour.
Clear the air passages of the foetus immediately
It is remembered by ABCD arrangement:
Air passages suction:
is stimulated by slapping the soles of the foetus,
flexion and extension of the legs and rubbing the back.
Mouth to mouth breathing: A one layer piece of
gauze is placed on the infant’s mouth close its nose with the fingers
and expire gently into the mouth. The expired O2 and CO2 will stimulate
the respiratory centre.
Endotracheal intubation and intermittent positive
pressure ventilation not exceeding 20 cm water.
Sodium bicarbonate: 1 mEq/kg is given IV to correct
Naloxone: 10 m g/kg is given IV as an antidote
to morphine or pethidine
Epinephrine: 0.1 ml/kg of 1:10.000 dilution is
injected into the umbilical vein or intracardiac.
Antibiotics: to guard against pneumonia which
is liable to develop after prolonged resuscitation.
Print this page
Edited by Aldo Campana,