Comment on

• Temporal trends and regional variations in severe maternal morbidity in Canada, 2003 to 2007.

  Liu S, Joseph KS, Bartholomew S, Fahey J, Lee L, Allen AC, Kramer MS, Sauve R, Young DC, Liston RM. Liu S, et al. J Obstet Gynaecol Can. 2010 Sep;32(9):847-855. doi: 10.1016/S1701-2163(16)34656-4. J Obstet Gynaecol Can. 2010. PMID: 21050517
• Temporal trends in maternal mortality in Canada I: estimates based on vital statistics data.

  Lisonkova S, Bartholomew S, Rouleau J, Liu S, Liston RM, Joseph KS; Maternal Health Study Group of the Canadian Perinatal Surveillance System. Lisonkova S, et al. J Obstet Gynaecol Can. 2011 Oct;33(10):1011-1019. doi: 10.1016/S1701-2163(16)35050-2. J Obstet Gynaecol Can. 2011. PMID: 22014778
• Temporal trends in maternal mortality in Canada II: estimates based on hospitalization data.

  Lisonkova S, Liu S, Bartholomew S, Liston RM, Joseph KS; Maternal Health Study Group of the Canadian Perinatal Surveillance System. Lisonkova S, et al. J Obstet Gynaecol Can. 2011 Oct;33(10):1020-30. doi: 10.1016/s1701-2163(16)35051-4. J Obstet Gynaecol Can. 2011. PMID: 22014779