Table 2 Participant factors which influence recruitment

Understanding of risk

▪ Women and parents may underestimate the risks involved in trial participation and overestimate the benefits [16–19, 23]

▪ Typically risks to the baby dominate over risks to the mother in decisions to participate in trials [19, 21–24]

Recruitment process and procedures

▪ The process of recruiting women and babies into trials has an impact on the decision to participate [17, 18, 22, 23]

▪ Communication skills of recruiters are important both to those recruiting and to potential research participants [16, 22, 24–29]

▪ There is conflicting evidence about the provision of written information such as patient information sheets [16–18, 22, 24]

▪ The timing and method of approach may impact on women's and parent's decision to participate [17, 19, 22, 30]

▪ Practical issues faced by potential participants include:

   - work and childcare commitments[28, 36]

   - transport issues [28, 36]

   - privacy and confidentiality concerns [28]

   - practical concerns about the trial medications/treatments [22, 28, 31]

Participants understanding of the research process and methodological issues

▪ Women and parents may not understand specific elements of trial design such as randomisation, blinding and the use of placebos [8, 16, 17, 21–23, 32, 33]

Patient characteristics

▪ Characteristics of patients may be related to women's and parent's decisions to participate in research:

   - altruism [20, 22, 23, 28, 34, 35]

   - attitudes and beliefs about research [28, 36]

   - cultural background [12, 37, 38]

   - language barriers [12, 37, 38]