This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

Primary objective: to assess the effectiveness and safety of invasive PDA closure strategies in preterm infants compared to medical management (pharmacotherapy or conservative) or no treatment.

Secondary objective: to analyse subgroups based on the following.

Postnatal age at intervention (less than four weeks versus late rescue)

Initial mode of treatment versus after failed medical management (based on courses and timing of pharmacotherapy)

Invasive closure following primary pharmacotherapy versus repeat pharmacotherapy

Within seven days versus after seven days

TCPC coil versus occluder

Gestational age (< 32 weeks versus 32 to 36 weeks)

Birth weight (< 1500 g or < 1000 g)

Weight at the time of the procedure (< 1000 g or > 1000 g)