Recruiting and enrolling pregnant adolescents for research.

Difficulty obtaining a sample is not justification for failure to study a hard-to-enroll population, particularly a vulnerable population such as pregnant adolescents. Recruitment of a representative, adequate sample of pregnant adolescents for a recent instrument development study provided multiple challenges. Although carefully developed, the sampling plan required several modifications to achieve the sample (n=145). Those challenges and the ensuing modifications to the sampling plan are discussed in relation to (a) access/institutional concerns, (b) the human subject's protection considerations, and (c) developmental/personal concerns of the pregnant adolescents. Recommendations for sampling strategies for future research are offered.