RAADP treatments are expected to be effective in preventing sensitisation. A dose of 1250 IU at 28 and 34 weeks is expected to be most effective and a single dose of 1500 IU at 28–30 weeks is expected to be least effective. Acknowledgments We are grateful to Giancarlo Manzi for initial analyses of the dose comparison data. We thank the reviewer for their helpful comments. References 1. Urbaniak SJ, Greiss MA (2000) RhD haemolytic disease of the fetus and the newborn. Blood Reviews 14: 44–61. 2. Stockman JA, de Alarcon PA (2001) Overview of the state of the art of Rh disease: history, current clinical management, and recent progress. Pediatric Hematology/Oncology 23: 385–93. 3. Whitfield CR, Raafat A, Urbaniak SJ (1997) Underreporting of mortality from RhD haemolytic disease in Scotland and its implications: retrospective review. BMJ 315: 1504–5. 4. Chilcott J, Lloyd Jones M, Wight J, Forman K, Wray J, et al. (2003) A review of the clinical effectiveness and cost-effectiveness of routine anti-D prophylaxis for pregnant women who are rhesus-negative. Health Technology Assessment 7(4). 5. Pilgrim H, Lloyd-Jones M, Rees A (2009) Routine antenatal anti-D prophylaxis for RhD-negative women: a systematic review and economic evaluation. Health Technology Assessment 13(10). 6. Bowman JM, Chown B, Lewis M, Pollock JM (1978) Rh isoimmunization during pregnancy: antenatal prophylaxis. Canadian Medical Association Journal 118: 623–7. 7. Bowman JM, Pollock JM (1978) Antenatal prophylaxis of Rh isoimmunization: 28-weeks’-gestation service program. Canadian Medical Association Journal 118: 627–30. 8. Bowman JM, Pollock JM (1987) Failures of intravenous Rh immune globulin prophylaxis: an analysis of the reasons for such failures. Transfusion Medicine Reviews 1: 101–12. 9. Hermann M, Kjellman H, Ljunggren C (1984) Antenatal prophylaxis of Rh immunization with 250 mg anti-D immunoglobulin. Acta Obstetricia et Gynecologica Scandinavica Suppl 124: 1–15. 10. Huchet J, Dallemagne S, Huchet C, Brossard Y, Larsen M, et al. (1987) Application ante´-partum du traitement pre´ventif d’immunisation Rhe´sus D chez les femmes Rhe´sus ne´gatif. Journal de Gyne´cologie obste´trique et biologie de la reproduction 16: 101–11. 11. Lee D, Rawlinson VI (1995) Multicentre trial of antepartum low-dose anti-D immunoglobulin. Transfusion Medicine 5: 15–9. Effectiveness of Antenatal Anti-D Prophylaxis Author Contributions Conceived and designed the experiments: JS HS MLJ ST RT DS. Performed the experiments: RT ST MLJ HS JS. Analyzed the data: MS RT ST. Contributed reagents/materials/analysis tools: DA SU RW MLJ GS DS RT ST. Wrote the paper: RT. Critically edited the manuscript: RT MLJ DA GS DS HS JS MS SU RW ST. 12. MacKenzie IZ, Bowell P, Gregory H, Pratt G, Guest C, et al. (1999) Routine antenatal Rhesus D immunoglobulin prophylaxis: the results of a prospective 10 year study. British Journal of Obstetrics and Gynaecology 106: 492–7. 13. Mayne S, Parker JH, Harden TA, Dodds SD, Beale JA (1997) Rate of RhD sensitisation before and after implementation of a community based antenatal prophylaxis programme. BMJ 315: 1588. 14. Tovey LAD, Townley A, Stevenson BJ, Taverner J (1983) The Yorkshire antenatal anti-D immunoglobulin trial in primigravidae. The Lancet 2: 244–6. 15. Trolle B (1989) Prenatal Rh-immune prophylaxis with 300 mg immune globulin anti-D in the 28th week of pregnancy. Acta Obstetricia et Gynecologica Scandinavica 68: 45–7. 16. de Craen AJM, van Vliet HAAM, Helmerhorst FM (2005) An analysis of systematic reviews indicated low incorporation of results from clinical trial quality assessment. Journal of Clinical Epidemiology 58: 311–3. 17. Moja LP, Telaro E, D’Amico R, Moschetti I, Coe L, et al. (2005) Assessment of methodological quality of primary studies by systematic reviews: results of the metaquality cross sectional study. BMJ 330: 1053–5. 18. Greenland S (2005) Multiple-bias modelling for analysis of observational data (with discussion). Journal of the Royal Statistical Society, Series A 168: 267–306. 19. Turner RM, Spiegelhalter DJ, Smith GCS, Thompson SG (2009) Bias modelling in evidence synthesis. Journal of the Royal Statistical Society, Series A 172: 21–47. 20. Clemen R, Winkler R (1999) Combining probability distributions from experts in risk analysis. Risk Analysis 19: 187–203. 21. Higgins JPT, Thompson SG, Deeks JJ, Altman DG (2003) Measuring inconsistency in meta-analyses. BMJ 327: 557–60. 22. Thompson SG, Sharp SJ (1999) Explaining heterogeneity in meta-analysis: a comparison of methods. Statistics in Medicine 18: 2693–708. 23. Szczepura A, Osipenko L, Freeman K (2011) A new fetal RHD genotyping test: Costs and benefits of mass testing to target antenatal anti-D prophylaxis in England and Wales. BMC Pregnancy and Childbirth 11: 5. PLoS ONE | www.plosone.org 10 February 2012 | Volume 7 | Issue 2 | e30711