Please cite this paper as: Bogers et al. (2012) Complications of the 2009 influenza A/H1N1 pandemic in pregnant women in The Netherlands: a national cohort study. Influenza and Other Respiratory Viruses 6(5), 309–312. The 2009 influenza A/H1N1 pandemic caused an increase in complications in pregnant women. To be well prepared for a next pandemic, we investigated the obstetric and maternal complications of this pandemic. In our national cohort of 59 pregnant women who were admitted to the hospital, no major complications apart from preterm birth and admission to the neonatal intensive care unit were observed. Although the small size of this study precludes us drawing any definitive conclusions, comparing our results with those in other countries suggests that the influenza A/H1N1 pandemic had a relatively benign course in pregnant women in The Netherlands.