NOTES FOR UNDERGRADUATES AND POSTGRADUATES IN GYNE

1. DR.PRIYA SAXENA

2.  The term fetal distress has been replaced by more appropriate ‘non-
reassuring fetal status’ which includes alteration of fetal heart rate on
electronic fetal monitoring like atypical and abnormal tracing (more severe).

3. PATHOPHYSIOLOGY
 Physiological control of heart rate includes a variety of interconnected
mechanisms which depend upon blood flow as well on oxygenation.
 In a normal fetus with adequate oxygenation, aerobic glycolysis and citric
acid cycle are predominant
 In case of chronic placental insufficiency and intrauterine hypoxia:
 Formation and deposition of lactic acid and pyruvic acid occurs through
anerobic glycolysis cause myocardial hypoxia, respiratory acidosis and
metabolic acidosis.
 Fetal tachycardia and bradycardia occur due to initial stimulation and later
depression of the cardiac pacemaker.
 Fetus may pass meconium due to vagal stimulation which enhances
intestinal activity and causes opening of anal sphincter.
 Total sudden cessation of oxygenation will affect the pontine region and
can cause sudden fetal death.

4. TYPES
 Acute fetal distress: in which distress occurs suddenly due to acute events
 Chronic fetal distress: occurs slowly usually due to chronic placental
insufficiency and fetal growth restriction

5. CAUSES
 Hypertonic uterine action
 Maternal position (supine position)
 Cord compression
 Cord prolapse
 Placental abruption
 Vasa previa
 Scar dehiscence or rupture of uterus
 Uterine overactivity due to uterotonics (oxytocin,prostaglandins)
 Maternal hypotension
 Certain drugs(eg-narcotic and non-narcotic analgesics)

6. DIAGNOSIS OF FETAL DISTRESS
 Abnormal fetal heart rate pattern are as follows:
o Persistent severe variable decelerations
o Persistent and non-remedial late decelerations
o Persistent severe bradycardia
 Meconium staining of the liquor
 Abnormal ph <7.20
 Low apgar score at 1 minute

7. MANAGEMENT
 Turn the woman on her side
 Administer oxygen (6-8 L/min) to improve fetal oxygen
 Check pulse , BP and temperature of the mother.
 Correct hypotension, if present by infusion of crystalloids dextrose saline or
Ringer lactate solution.
 Immediate delivery by cesarean section or instrumental delivery

8. THANK YOU