March 2013.

Methods	Randomised controlled trial. Random permuted blocks of 10.
Participants	Inclusion criteria Pregnant women likely to give birth to a singleton preterm infant between 24 and 28 completed weeks of gestation. 113 women and babies randomised, 56 to UCM and 57 to ECC. 38 (33.6%) were then excluded leaving 75 women, 36 UCM and 39 ECC. Exclusions mainly due to women going past 28 weeks' gestation. Exclusion criteria Antenatally diagnosed major fetal congenital anomaly; known Rh sensitisation; hydrops fetalis; known recent maternal exposure to parvovirus; elevated peak systolic velocity of the fetal middle cerebral artery or clinical suspicion of placental abruption at delivery due to excessive maternal bleeding or uterine hypertonicity.
Interventions	Intervention: UCM An extended hand’s width length of cord (from the tip of the thumb to the tip of the pinky finger, 20 ± 2 cm) was used as the standard. Infants in the cord milking group were placed at or below the level of the placenta if born vaginally or at the same level as the placenta if born by CS. 20 cm of the umbilical cord was actively milked towards the umbilicus 3 times before clamping the cord. Infants in the control group had the cord clamped and cut immediately after delivery. N = 36 babies Comparator: ECC Immediate clamping N = 39 babies Additional information Gestational subgroup: < 32‐34 weeks' gestation Resuscitation with cord intact: not available Access to NICU: yes Length of delay: n/a Baby placed: below level of placenta When uterotonic given: no information UCM: cord intact during UCM Comparison 7 UCM vs ECC (subgroup by gestation) Subgroup 1: < 32‐34 weeks' gestation Comparison 8 UCM vs ECC (subgroup by type of intervention) Subgroup 1: cord intact during UCM
Outcomes	Primary Red cell transfusion at 28 days Secondary Apgar scores, umbilical cord pH, type of resuscitation, initial neonatal Hb and Hct, initial neonatal BP, time (in days) from birth to transfusion, total volume of RBCs transfused in the first 28 days of life, need for phototherapy, number of days of phototherapy and known complications of prematurity such as RDS, IVH (including stage), PVL, chronic lung disease, RoP, hyperkalaemia, sepsis, NEC (defined by Bell’s criteria) and death
Notes	Setting: East Virginia, USA. Single tertiary centre. Dates: September 2009 to June 2011 Declaration of interest: authors declare no conflicts of interest. Trial funding source: this work was conducted with support from Harvard Catalyst. The Harvard Clinical and Translational Science Center (National Center for Research Resources and the National Center for Advancing Translational Sciences, National Institutes of Health Award 8UL1TR000170‐05 and financial contributions from the Harvard University and its affiliated academic healthcare centres. Further information Dr Melisa March kindly provided clarification and additional data in a personal communication on 19 November 2015.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	‘An independent statistician provided the randomisation sequence.’ Personal communication with Dr March provided the following information: Quote: “A statistician provided random permuted blocks of 10 using a SAS program."
Allocation concealment (selection bias)	Low risk	'Serially numbered opaque envelopes'
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "The neonatologists and pediatric support staff were not blinded to treatment assignment given that they were required to be present for the delivery."
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote: "The neonatologists and pediatric support staff were not blinded to treatment assignment given that they were required to be present for the delivery....no notation of study participation was made in the neonate’s chart in order to minimize the possibility that postnatal treatment decisions would be influenced by study participation."
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	33.6% of women were excluded because they gave birth beyond 28 weeks' gestation. This was 16 in each group and so we believe this is unlikely to cause serious bias but unclear.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Low risk	Baseline characteristics were similar in the groups. Compliance: 1 woman in the cord milking group had the cord inadvertently clamped and cut immediately. This was dealt with by ITT.