Persistent fetal circulation

Persistent fetal circulation is a condition caused by a failure in the systemic circulation and pulmonary circulation to convert from the antenatal circulation pattern to the "normal" pattern.

In a fetus, there is high pulmonary vascular resistance and low pulmonary blood flow as the fetus does not use the lungs for oxygen transfer. Once the baby is born, the lungs are needed for oxygen transfer and need high blood flow which is encouraged by low pulmonary vascular resistance.

It can be associated with pulmonary hypertension.^[1] Because of this, the condition is also known as "persistent pulmonary hypertension of the newborn".^[2]

Epidemiology

1-2 infants per 1000 live births^[3]

Types

Normal vascular anatomy with functional vasoconstriction

Good prognosis as reversible

Causes - hypoxia, meconium aspiration, respiratory distress syndrome

Decreased diameter of pulmonary vessels with hypertrophy of vessel walls

Poor prognosis as fixed abnormality

Causes - post term pregnancy, placental insufficiency, NSAID use by mother

Decreased size of pulmonary vascular bed

Poor prognosis as fixed abnormality

Causes - space occupying lesions i.e. pleural effusions, diaphragmatic hernia

Functional obstruction of pulmonary blood flow

Good prognosis if reversible

Causes - polycythemia, hyperfibrinogenemia ^[4]

Treatment

Treatment aims to increase the amount of oxygen in the blood and reverse any causes of hypoxia.

• oxygen therapy
• mechanical ventilation
• NO Inhalation
• Prostaglandins (intravenous)

References

External links

• http://www.kumc.edu/instruction/medicine/pedcard/cardiology/pedcardio/pfcdiagram.gif
• Dunn PM (March 1994). "Professor Charles D Meigs (1792-1869) of Philadelphia and persistent fetal circulation". Arch. Dis. Child. Fetal Neonatal Ed. 70 (2): F155–6. doi:10.1136/fn.70.2.F155. PMC 1061019. PMID 8154909. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1061019.