Appendices 2 and 3 are not available in the digital version of this thesis. Research related to this thesis is published in the following papers: 1. Reulen RC, Zeegers MP, Wallace WHB, Frobisher C, Taylor AJ, Lancashire ER, Winter DL, Hawkins MM. Pregnancy outcomes among adult survivors of childhood cancer in the British Childhood Cancer Survivor Study. Cancer Epidemiol Biomarkers Prev 2009:18:2239-47. 2. Reulen RC, Taylor AJ, Winter DL, Stiller CA, Frobisher C, Lancashire ER,McClanahan FM, Sugden EM, Hawkins MM. Long-term population-based risks of breast cancer after childhood cancer. Int J Cancer 2008;123:2156-63. 3. Reulen RC, Zeegers MP, Lancashire ER, Winter DL, Hawkins MM. Offspring sex ratio and gonadal irradiation in the British Childhood Cancer Survivor Study. Br J Cancer 2007;96:1439-41. 4. Reulen RC, Winter DL, Lancashire ER, Zeegers MP, Jenney ME, Walters SJ, Jenkinson C, Hawkins MM. Health-status of adult survivors of childhood cancer: A large-scale population-based study from the British childhood cancer survivor study. Int J Cancer 2007;121:633-40. 5. Reulen RC, Zeegers MP, Jenkinson C, Lancashire ER, Winter DL, Jenney ME, Hawkins MM. The use of the SF-36 questionnaire in adult survivors of childhood cancer: evaluation of data quality, scoring reliability, and scaling assumptions. Health Qual Life Outcomes 2006:4:77. 6. Hawkins MM, Lancashire ER, Winter DL, Frobisher C, Reulen RC, Taylor AJ, Stevens MC, Jenney M. The British Childhood Cancer Survivor Study: Objectives, methods, population structure, response rates and initial descriptive information. Pediatr Blood Cancer 2008:50:1018-25.