Abstract
OBJECTIVE: Delayed-interval delivery (DID) is the delivery of the first fetus in a multiple gestation pregnancy without prompt delivery of the remaining fetus(es). We aimed to assess infant outcomes of DID. STUDY DESIGN: We performed a retrospective cohort study of infants born 22-28 weeks' gestation or weighing 401-1500 g. DID was defined as a passage of >24 h between the birth of firstborn and retained infants. Rates of mortality, morbidity, and developmental outcomes were compared within DID multiples, to other multiples not born by DID, and all infants in the Generic Database and follow-up datasets (excluding DID-born). RESULTS: DID-born multiples were younger and smaller than other multiples. Retained infants had no significantly different rates of mortality and morbidities compared to their firstborn counterparts, apart from less bronchopulmonary dysplasia. CONCLUSIONS: DID showed no evidence of harm and a potential benefit of decreased bronchopulmonary dysplasia mediated by increased gestational age and birthweight.