Association of patent ductus arteriosus and severe hypothyroidism in term newborns: coincidence or causal?

We report on 3 term newborns with the association of patent ductus arteriosus (PDA) and severe hypothyroidism attributed to thyroid agenesis (n = 2) or feto-maternal pit-1 deficiency (n = 1). This association suggests that sufficient thyroid hormone availability is among the prerequisites for normal postnatal ductal closure. Unravelling the maturational effects of thyroid hormone on the ductus arteriosus might also be relevant in preterm infants as further studies of the perinatal thyroid axis may clarify the potential role of thyroid hormone in PDA closure in preterm infants. Based on our observation, hypothyroidism should be considered in term infants with PDA.