Carlsen 2013.

Methods	Parallel‐group RCT to determine if telephone‐based support could improve breastfeeding outcomes in obese mothers
Participants	Setting: Denmark, hospital that does not have Baby Friendly Hospital certification Recruitment: December 2010‐June 2012 Inclusion criteria: women‐infant dyads with a healthy singleton infant, born at term (> 258 days of gestation), < 48 h postnatal age. Women intending to breastfeed with no previous history of breast surgery. All women had participated in the Treatment of Obese Pregnant study (TOP‐study) at the hospital, which had inclusion criteria of pre‐pregnancy BMI ≥ 30 kg/m² and an aim to minimise gestational weight gain (i.e. gain max 5 kg). Exclusion criteria: sick infants requiring admission to NICU and infants with congenital diseases or malformations
Interventions	Breastfeeding support intervention n = 108, usual care n = 118 Telephone‐based breastfeeding support by a International Board Certified Lactation Consultant for 6 months The telephone‐based advisory support service was performed by a single International Board Certified Lactation Consultant. Contacts followed a structured design posing questions of physical and psychological aspects related to breastfeeding and well‐being of the mother and child. Advice was given if the mother was deemed to have insufficient breastfeeding knowledge. Any breastfeeding difficulties were discussed and possible solutions identified. The first contact was approximately 20 min (within the first week), follow‐up contacts were 5‐10 min (x 3 in 1st month, every other week thereafter until 8 weeks and then monthly). The direct contact number of the lactation consultant also given to the women; the lactation consultant was available 7 days/week, so there were extra contacts for specific difficulties. All participants were offered a minimum of 9 consultations in the first 6 months (or until they had ceased all breastfeeding).
Outcomes	Exclusively breastfeeding and any breastfeeding data were collected by telephone at 3 and 7 days, 2 and 4 weeks, 3, 4 and 6 months Exclusive breastfeeding was defined as breastfeeding only supplemented with vitamins, mineral supplements, or water. Partial breastfeeding was defined as breastfeeding supplemented with formula milk or solid food. Infant weight, length, head circumference and abdominal circumference measured at the level of the umbilicus were taken at birth and 6 months. In addition at 6 months triceps and subscapular skinfold thickness were measured using a Harpendens skinfold calliper. All measures (except weight) were taken in triplicate and a mean obtained.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Mother‐newborn dyads were allocated (1:1) to the intervention by telephone support or control standard care by using a web‐based independent program."
Allocation concealment (selection bias)	Low risk	Independent web‐based program used therefore low risk of allocation being known prior to randomisation.
Blinding of participants and personnel (performance bias) All outcomes	High risk	It was not possible to blind participants or the lactation consultant to group allocation. This could have led to performance bias and affected outcomes, as breastfeeding outcomes were self‐reported.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The intervention was blinded to the study staff, which collected data on breastfeeding status and infant growth. The lactation consultant was not involved in measuring infants."
Incomplete outcome data (attrition bias) All outcomes	Low risk	All women recruited accounted for in the study flow diagram. < 20% attrition rate for breastfeeding and infant growth outcomes at 6 months
Selective reporting (reporting bias)	Unclear risk	This study was assessed from a published report without access to the protocol, therefore we cannot be certain whether all pre‐specified outcomes were reported.
Other bias	Low risk	Group sizes differed (108 vs 118) however simple randomisation was undertaken, so we judged this to have occurred by chance.