What Is Ductus Arteriosus?
The ductus arteriosus (DA) is an opening between two of the major blood vessels of the heart. When your baby is still inside the womb, the placenta does the work of exchanging oxygen (O2) and carbon dioxide (CO2) through the mother's circulation. The baby’s lungs are not used for breathing.
What Is Patent Ductus Arteriosus (PDA)?
When your baby is born and starts breathing, the DA closes and gas exchange occurs in your baby’s lung. Sometimes the DA does not close, especially in very preterm babies. The PDA is called “persistent ductus arteriosus” if it remains open after the time of its expected closure which normally occurs 1-3 days after birth in a term baby.
How Common Is PDA?
PDA is a common problem in premature infants. From 20% of premature infants born between 32 - 36 weeks' gestation, and up to 60% in those born at less than 28 weeks' gestation have PDA.
What Are The Signs And Symptoms Of PDA?
A heart murmur may be the only sign that a baby has PDA. A heart murmur is an extra or unusual sound heard during the heartbeat. Sometimes, they may develop low blood pressure (hypotension).
Some babies may develop signs of overfilling of the lungs (“wet lungs”) due to shunting across the PDA and recycling of the blood through the lungs. These signs may include: fast breathing, working hard to breathe, or shortness of breath. Premature babies will require an increase in their respiratory support to cope with their “wet lungs”.
How Is PDA Diagnosed?
PDA is diagnosed by Doppler echocardiography (echo). An echo is a painless test that uses sound waves to create a moving picture of your baby's heart. This is very similar to the ultrasound scans done on the mother during pregnancy.
What Is The Treatment Of PDA?
The goal of treatment is to close the PDA to prevent complications. The decision to treat the PDA depends on the size of the duct and the clinical condition of your baby. Small ducts may not require treatment and usually close without specific medical treatment.
Specific treatment for PDA:
In premature babies, an anti-inflammatory drug called ibuprofen may be used. Ibuprofen has been shown to be effective in closing the PDA. Sometimes a few courses of the medication may be required if the PDA fails to close or re-opens again.
If a PDA does not respond to medication, or is due to causes other than prematurity, surgery may be needed. This surgery is called ligation and involves placing a suture or clip around the ductus to close it.
Supportive treatment includes:
Increased oxygen, increased respiratory support either in the form of CPAP or ventilation and/or limiting fluid intake to decrease the effect of “wet lungs” and sometimes use a diuretic to get rid of the excess fluid
Prognosis and Long Term Outcome
Most babies tolerate the treatment of PDA well. The long term outcome is more dependent on the age and birth weight of your baby. Need for surgery does have some impact on the long term neuro developmental outcome of preterm babies. There is no significant inheritance pattern for PDA.