Randomised controlled trial of preconception lifestyle intervention on maternal and offspring health in people with increased risk of gestational diabetes: study protocol for the BEFORE THE BEGINNING trial

Abstract

IntroductionGestational diabetes mellitus (GDM) is associated with increased risk for type 2 diabetes in the mother and cardiometabolic diseases in the child. The preconception period is an optimal window to adapt the lifestyle for improved outcomes for both mother and child. Our aim is to determine the effect of a lifestyle intervention, initiated before and continued throughout pregnancy, on maternal glucose tolerance and other maternal and infant cardiometabolic outcomes.Methods and analysisThis ongoing randomised controlled trial has included 167 females aged 18–39 years old at increased risk for GDM who are contemplating pregnancy. The participants were randomly allocated 1:1 to an intervention or control group. The intervention consists of exercise (volume is set by a heart rate-based app and corresponds to ≥ 1 hour of weekly exercise at ≥ 80% of individual heart rate maximum), and time-restricted eating (≤ 10 hours/day window of energy intake). The primary outcome measure is glucose tolerance in gestational week 28. Maternal and offspring outcomes are measured before and during pregnancy, at delivery, and at 6–8 weeks post partum. Primary and secondary continuous outcome measures will be compared between groups based on the ‘intention to treat’ principle using linear mixed models.Ethics and disseminationThe Regional Committees for Medical and Health Research Ethics in Norway has approved the study (REK 143756). The anonymised results will be submitted for publication and posted in a publicly accessible database of clinical study results.Trial registration numberClinical trial govNCT04585581.

Feasibility of time-restricted eating during pregnancy and effect on glycemic control in people with increased risk of gestational diabetes – a randomized controlled trial

“…21 The on-going BEFORE THE BEGINNING trial will determine the feasibility of TRE also in early pregnancy. 22 There was no effect of TRE on any of the measured cardiometabolic outcomes in our study. A reason for this could be that 5 weeks may be insu cient to induce any signi cant glycemic changes in pregnant individuals.…”

Multigenerational diabetes mellitus

“…Furthermore, pre-pregnancy adherence to Mediterranean diet also decreases the risk of developing GDM, regardless of weight and other risk factors, in particular, avoidance of pre-conception consumption of processed and fatty meats ( 141 , 142 ). “Before the Beginning”, an RCT of preconception lifestyle intervention that is currently ongoing, is examining the effect of time-restricted eating and exercise on maternal glucose tolerance at 28 weeks gestation ( 143 ).Time-restricted eating has been demonstrated to be a feasible lifestyle intervention in those with obesity and T2D outside of pregnancy ( 144 ), however adherence in pregnancy may be more challenging outside of the more intensive support offered during an RCT.…”

Feasibility of time-restricted eating during pregnancy and effect on glycemic control in people with increased risk of gestational diabetes – a randomized controlled trial

“…21 The on-going BEFORE THE BEGINNING trial will determine the feasibility of TRE also in early pregnancy. 22…”