Fetal distress

LIN QI DE 2005.9.5

Fetal distress is defined as depletion of oxygen and accumulation of carbon dioxide,leading to a state of “hypoxia and acidosis ” during intra-uterine life.

Definition

Maternal factors1) Microvascular ischaemia(PIH)2) Low oxygen carried by RBC(severe

anemia)3) Acute bleeding(placenta previa,

placental abruption) 4) Shock and acute infection5) obstructed of Utero-placental blood

flow

Etiology

Placenta 、 umbilical factors

1) Obstructed of umbilical blood flow2) Dysfunction of placenta3) Fetal factors4) Malformations of cardiovascular

system5) Intrauterine infection

Etiology

Hypoxia 、 accumulation of carbon dioxide ￬

Respiratory Acidosis￬

FHR ￪ → FHR ￬→ FHR ￪ ￬

Intestinal peristalsis￬

Relaxation of the anal sphincter￬

Meconium aspiration￬

Fetal or neonatal pneumonia

Pathogenesis

Acute fetal distress

ChronicFetaldistress

Pathogenesis

IUGR(intrauterine

growth retardation)

Clinical manifestation

Acute fetal distress (1)FHR FHR>180 beats/min (tachycardia) <100 beats/min (bradycardia) (LD) Repeated Late deceleration Placenta dysfunction (VD) Variable deceleration Umbilical factors

FHR:120~160 bpm / FHR variability

Early deceleration ， ED

Late deceleration ， LD

Variable deceleration ， VD ）

Clinical manifestationAcute fetal distress (2) Meconium staining of the amniotic fluid

grade I 、 II 、 III (3) Fetal movement Frequently→decrease and weaken (4) Acidosis FBS (fetal blood sample) pH<7.20 pO2<10mmHg (15~30mmHg)

CO2>60mmHg (35~55mmHg)

Clinical manifestation

Chronic fetal distress

(1) Placental function

(24h E3<10mg or E/C<10)

(2) FHR

(3) BPS

(4) Fetal movement

(5) Amnioscopy

Management Remove the induced factors

actively Correct the acidosis: 5%NaHCO3 250ML

Terminate the pregnancy (1) FHR>160 or <120 bpm meconium staining (II~III) (2) Meconium staining grade III amniotic fluid volume<2cm (3) FHR<100 bpm continually

Management Terminate the pregnancy (4) Repeated LD and severe VD (5) Baseline variability disappear

with LD (6) FBS pH<7.20 Forceps delivery Caesarean section