Neonatal outcomes in preterm multiples receiving delayed cord clamping

Objective To compare neonatal outcomes in singletons versus multiples, first-born versus second-born multiples and monochorionic versus dichorionic/trichorionic multiples <33 weeks' gestational age (GA) who received delayed cord clamping (DCC). Design Retrospective, observational study of 529 preterm infants receiving >= 30 s DCC. Generalised estimating equations and mixed effects models were used to compare outcomes in singletons versus multiples and monochorionic versus dichorionic/trichorionic multiples. Wilcoxon signed-rank and McNemar tests were used to compare first-born versus second-born multiples. Setting Level III neonatal intensive care unit, California, USA. Patients 433 singletons and 96 multiples <33 weeks' GA, born January 2008-December 2017, who received DCC. Results 86% of multiples and 83% of singletons received DCC. Multiples had higher GA (31.0 weeks vs 30.6 weeks), more caesarean sections (91% vs 54%), fewer males (48% vs 62%) and higher 12-24 hour haematocrits (54.3 vs 50.5) than singletons. Haematocrit difference remained significant after adjusting for birth weight, delivery type and sex. Compared with first-born multiples, second-born multiples were smaller (1550 g vs 1438 g) and had lower survival without major morbidity (91% vs 77%). Survival without major morbidity was not significant after adjusting for birth weight. Compared with dichorionic/trichorionic multiples, monochorionic multiples had slightly lower admission temperatures (37.0 degrees C vs 36.8 degrees C), although this difference was not clinically significant. There were no other differences in delivery room, respiratory, haematological or neonatal outcomes between singletons and multiples or between multiples' subgroups. Conclusions Neonatal outcomes in preterm infants receiving DCC were comparable between singletons and multiples, first and second order multiples and monochorionic and dichorionic/trichorionic multiples.