Background: With the increased birth rate of twins during the recent decades and improved prognosis of preterm infants, there is a need to explore measures that could optimise their growth and neurodevelopmental outcomes. It has been postulated that co-bedding simulates the twins' intrauterine experiences in which co-regulatory behaviours between the twins are observed. These behaviours are proposed to benefit the twins by reducing their stress, which may promote growth and development. However, uncertainties exist on the benefit-risk profile of co-bedding in practice.
Objectives: We aimed to assess the effects of co-bedding on growth, and other clinically relevant physiological and neurodevelopmental outcomes for stable preterm twins.
Search methods: We used the standard search strategy of the Cochrane Neonatal Review Group (CNRG). We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2012, Issue 7), MEDLINE (via PubMed), EMBASE (hosted by EBCHOST), CINAHL and references cited in our shortlisted articles using keywords and MesH headings, up to July 2012.
Selection criteria: We included randomised controlled trials with randomisation either at the level of each twin pair and/or at the level of neonatal unit. We excluded cross-over studies.
Data collection and analysis: We extracted data using the standard methods of the CNRG. Two review authors independently assessed the relevance and risk of bias of the retrieved records. We contacted the authors of the included studies if important information was missing from their published papers. We expressed our results using risk ratio (RR) and mean difference (MD) where appropriate with their 95% confidence intervals (CIs). We adjusted the unit of analysis from individual infants to twin pairs by averaging the measurement for each twin pair (continuous outcome) or by counting the outcome as positive if any of the twins developed the outcome (dichotomous outcome).
Main results: Five studies met the inclusion criteria; however, data were only available for analysis in four studies. Four of the five included studies were small and had significant limitations in design. As each study reported the outcomes differently, data for most of the outcomes were effectively contributed by a single study. There were no differences between co-bedded twins and twins that received separate care in the rate of weight gain (MD 0.20 grams/kg/day, 95% CI: -1.60 to 2.00), apnoea, bradycardia and desaturation (A/B/D) episodes (RR: 0.85, 95% CI: 0.18 to 4.05; 1 study), length of hospital stay (MD -4.90 days, 95% CI: -35.23 to 25.43) and infection rates (typical RR: 0.84, 95% CI: 0.30 to 2.31; 3 studies). There were also no differences in parental perceptions of care. Co-bedded twins appeared to spend more time crying, but they also seemed to spend more time in quiet sleep. There was low or very low quality of evidence across all the outcomes.
Authors' conclusions: There was insufficient evidence on the benefits and harms of co-bedding stable preterm twins to make any recommendation in practice. There is a need for future studies that are adequately powered to detect clinically important differences in growth and neurodevelopment. Such studies should also assess harms including infections and medication errors, and caregiver satisfaction.