Katheria 2015.

Methods	Randomised controlled trial, stratified by gestation and mode of birth
Participants	Inclusion criteria Babies less than 32 weeks' gestation born by CS Entry criteria included a gestational age of 23 0/7 to 31 6/7 weeks Multiple pregnancies included (though monochorionic multiples excluded) We did include infants with perinatal depression because it would not be feasible to detect perinatal depression at the time of delivery N = 197 babies randomised: 43 for vaginal birth analysis and 154 for CS analysis Exclusion criteria Monochorionic multiples; incarcerated mothers; placenta previa; concern for abruptions; Rh sensitization; hydrops, congenital anomalies; or the obstetrician declining to perform the intervention (i.e. unaware of the study protocol)
Interventions	Intervention: DCC DCC was performed by holding the infant at or ∼20 cm below the level of the placenta and waiting at least 45 secs before clamping the cord In both arms, infants were dried and wrapped with sterile towels until the cord was clamped Total number randomised for CS analysis: N = 79 Total number randomised for VB analysis: N = 20 Comparator: UCM UCM was performed by holding the infant at or approximately 20 cm below the level of the placenta. The cord was pinched as close to the placenta as possible and milked toward the infant over a 2‐second duration. The cord was then released and allowed to refill with blood for a brief 1‐ to 2‐secs pause between each milking motion. This was repeated for a total of 4 times. After completion, the cord was clamped, and the neonate was handed to the resuscitation team. In both arms, infants were dried and wrapped with sterile towels until the cord was clamped N = total number randomised for CS analysis: N = 75 N = total number randomised for VB analysis: N = 23 Additional information Gestational subgroup: < 32‐34 weeks' gestation Resuscitation with cord intact: not available Access to NICU: yes Length of delay: 45 secs Baby placed: low Uterotonic: no information UCM: with cord intact Comparison 5 DCC with neonatal resuscitation after cord clamping vs UCM (subgroup by gestation) Subgroup 1: < 32‐34 weeks' gestation Comparison 6 DCC with neonatal resuscitation after cord clamping vs UCM (subgroup by type of intervention) Subgroup 2: DCC at < 1 min with baby low (+ gravity)
Outcomes	Primary: Systemic blood flow Secondary: Hemodynamic outcomes; Hb at birth; polycythaemia; urine output in first 24 hrs; need for transfusion; peak bilirubin; NEC; RoP: spontaneous intestinal perforation; oxygen at 36 weeks (corrected); any IVH; severe IVH (≥ grade 3); sepsis; death
Notes	Setting: California, USA. 2 tertiary centres (Sharp Mary Birch Hospital for Women and Newborns (SMBHWN) and Loma Linda University Medical Center) Dates: interim analysis August 2013 ‐ August 2014. Declaration of interest: “The authors have indicated they have no potential conflicts of interest to disclose.” and“The authors have indicated they have no financial relationships relevant to this article to disclose.” Trial funding source: “All phases of this study were supported by a National Institutes of Health (NIH) grant 5R03HD072934‐02. Funded by the National Institutes of Health (NIH).” Further information: Multiples (twins or triplets) received the same random assignment. Hemodynamic measurements were only performed at site 1 (SMBHWN). Received information from A Katheria on 10.04.16 regarding methodology. The study included women giving birth vaginally and by caesarean, and the main publication reports on women giving birth by caesarean section, We have reported only on death before discharge as this is the only data currently available on the whole cohort (Katheria 2017). We are in communication with A Katheria to obtain further outcome data on the whole cohort. Neurodevelopmental outcomes at 22‐26 months corrected age are reported in Katheria 2018. Data were available on 74% of the babies. We report in 'Data and analysis' the outcome 'Moderate to severe neurodevelopmental impairment' assessed by Bayley 111 and defined by the authors as: “ ≥ 1 of the following: a Cognitive composite score of < 70, GMFCS of ≥ 2, blindness (vision of < 20/200), or hearing impairment interfering with the ability to communicate with amplification.”. The paper focuses on the individual components of cognitive, language and motor skills. They report a significantly better scores for babies who had UCM for the cognitive and the language components.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote:“Computer‐generated randomisation was stratified by age and mode of birth”
Allocation concealment (selection bias)	Low risk	Quote: “Infants were randomly assigned by opaque, sealed envelopes immediately before delivery”. Also the envelopes were handed out in a pre‐defined blinded order to provide allocation concealment (personal communication from A Ketheria).
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote:"The obstetricians were made aware of the randomization by the neonatology team immediately before delivery of the infant."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote:"Blinded echocardiograms and head ultrasounds were performed mainly (.90%) by the principal investigator (A.C.K.). None of the investigators performing echocardiograms were involved in the randomization or the recording of the intervention. All images were analyzed and measured offline by using EchoPAC software (GE HealthCare, Horten, Norway) and were analyzed without knowledge of the assigned group by the principal investigator. The blinding was achieved by allowing only the ALS nurse attending the delivery and the obstetrician performing the intervention to be aware of the allocation arm."
Incomplete outcome data (attrition bias) All outcomes	High risk	Only reported outcomes on caesarean births and not the vaginal births (a few outcomes in a supplementary on‐line sheet).
Selective reporting (reporting bias)	High risk	Not all outcomes listed in trial protocol are reported on, e.g. omitted admission to NICU and inotropic support, etc.
Other bias	Unclear risk	Similar at baseline. ITT but stopped trial following interim analysis.