Comment on

• No beneficial effect of preimplantation genetic screening in women of advanced maternal age with a high risk for embryonic aneuploidy.

  Twisk M, Mastenbroek S, Hoek A, Heineman MJ, van der Veen F, Bossuyt PM, Repping S, Korevaar JC. Twisk M, et al. Hum Reprod. 2008 Dec;23(12):2813-7. doi: 10.1093/humrep/den231. Epub 2008 Jun 21. Hum Reprod. 2008. PMID: 18567895 Clinical Trial.
• Preimplantation genetic screening in women of advanced maternal age caused a decrease in clinical pregnancy rate: a randomized controlled trial.

  Hardarson T, Hanson C, Lundin K, Hillensjö T, Nilsson L, Stevic J, Reismer E, Borg K, Wikland M, Bergh C. Hardarson T, et al. Hum Reprod. 2008 Dec;23(12):2806-12. doi: 10.1093/humrep/den217. Epub 2008 Jun 25. Hum Reprod. 2008. PMID: 18583331 Clinical Trial.
• Preimplantation genetic screening does not improve delivery rate in women under the age of 36 following single-embryo transfer.

  Staessen C, Verpoest W, Donoso P, Haentjens P, Van der Elst J, Liebaers I, Devroey P. Staessen C, et al. Hum Reprod. 2008 Dec;23(12):2818-25. doi: 10.1093/humrep/den367. Epub 2008 Oct 17. Hum Reprod. 2008. PMID: 18930977 Clinical Trial.
• What next for preimplantation genetic screening? More randomized controlled trials needed?

  Mastenbroek S, Scriven P, Twisk M, Viville S, Van der Veen F, Repping S. Mastenbroek S, et al. Hum Reprod. 2008 Dec;23(12):2626-8. doi: 10.1093/humrep/den376. Epub 2008 Oct 23. Hum Reprod. 2008. PMID: 18948310