title: A randomised controlled demonstration trial of multifaceted nutritional intervention and or probiotics: the healthy mums and babies (HUMBA) trial.
abstract: Maternal obesity is associated with adverse pregnancy outcomes and has lifelong negative implications for offspring health. The Institute of Medicine recommends limited gestational weight gain (GWG) in obese women for optimal maternal and infant outcomes. However, there is a gap regarding an effective and sustainable intervention strategy to achieve this goal. The aim of the healthy mums and babies (HUMBA) demonstration trial is to assess whether a multifaceted nutritional intervention and/or an oral probiotic treatment in obese pregnant women can reduce excessive GWG and optimise pregnancy outcomes.
  
  
  
  The study is a two by two factorial randomised controlled demonstration trial conducted in Counties Manukau health region, New Zealand, a multi-ethnic region with a high prevalence of obesity. A total of 220 non-diabetic obese women with a singleton pregnancy will be recruited between 120and 176weeks. At recruitment, women are randomised to receive either a culturally tailored multifaceted dietary intervention or routine dietary advice, and either an oral probiotic or placebo capsule. Randomisation is undertaken via a web-based protocol, randomize.net, with a 1:1 ratio using stratification by body mass index (BMI) category (BMI of 30-34.9 or BMI ≥35 kg/m2). The dietary intervention includes 4 customised nutrition education visits by a trained community health worker combined with motivational text messaging. Probiotic capsules consist of Lactobacillus rhamnosus GG and Bifidobacterium lactis BB12 at a dose of 7 × 109colony-forming units one per day until birth. Probiotic and placebo capsules are identically pre-packed and labelled by a third party, and are prescribed in a double blinded fashion. Research assessments are conducted at enrolment, 28 weeks, 36 weeks, at birth and at 5 months post-delivery. The primary outcomes for the study are proportion of women with excessive GWG and infant birthweight.
  
  
  
  The HUMBA demonstration trial will assess the efficacy of a culturally tailored multifaceted dietary intervention and probiotic treatment in limiting excessive GWG and optimising birthweight in a multiethnic sample of obese pregnant women. If successful, either one or both of the interventions may be incorporated into future studies powered to investigate important pregnancy outcomes.
  
  
  
  Australian New Zealand Clinical Trials Registry registration number: ACTRN12615000400561 , Universal Trial Number: U1111-1155-0409. Date registered: 29thApril 2015.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medical and Health Science, University of Auckland, Private Bag 92019, Auckland, New Zealand.|South Auckland Clinical School, Faculty of Medical and Health Science, The University of Auckland, Auckland, New Zealand.
authors.forename: Karaponi
authors.initials: K
authors.lastname: Okesene-Gafa
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medical and Health Science, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Minglan
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medical and Health Science, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Rennae S
authors.initials: RS
authors.lastname: Taylor
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medical and Health Science, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: John M D
authors.initials: JMD
authors.lastname: Thompson
authors.affiliation: The Liggins Institute, The University of Auckland, Auckland, New Zealand.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Crowther
authors.affiliation: The Liggins Institute, The University of Auckland, Auckland, New Zealand.|Department of Paediatrics, Child and Youth Health, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Christopher J D
authors.initials: CJD
authors.lastname: McKinlay
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medical and Health Science, University of Auckland, Private Bag 92019, Auckland, New Zealand. l.mccowan@auckland.ac.nz.|South Auckland Clinical School, Faculty of Medical and Health Science, The University of Auckland, Auckland, New Zealand. l.mccowan@auckland.ac.nz.
authors.forename: Lesley M E
authors.initials: LME
authors.lastname: McCowan
mesh_terms: D015992:Body Mass Index; D004032:Diet; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D009765:Obesity / Q000628:therapy*; D010353:Patient Education as Topic; D011247:Pregnancy; D011248:Pregnancy Complications / Q000628:therapy*; D019936:Probiotics / Q000627:therapeutic use*; D012107:Research Design; D060145:Text Messaging; D015430:Weight Gain / Q000187:drug effects*
keywords: Birthweight; Gestational weight gain; Nutritional intervention; Obesity; Probiotics; Randomised controlled trial; Study protocol