The aim of the study was to estimate the risk factors associated with the 2009 H1N1 influenza infection, during pregnancy; to describe complications and obstetric and perinatal outcomes of pregnancies during the H1N1 pandemic in 2009; to identify if there is teratogenicity at birth after antiviral treatment. Medical records of 168 pregnant women treated in Reina Sofia University Hospital (Cordoba, Spain) for suspected influenza A H1N1 from September 2009 to February 2010 were analysed. Using the PCR test, 76 pregnant women were diagnosed with H1N1 + infection, and infection was ruled out in the remaining 92. To manage the pandemic, recommendations of the Centres for Disease Control and Prevention were followed. Results showed that the majority of pregnant women were attended at the hospital between October and December 2009 (91.27%). Most of them were in the third-quarter of pregnancy (42.9%). In our sample, being aged between 29 and 37 years reduces the risk of acquiring infection (odds ratio, OR 0.379, 95% confidence interval, CI 0.188-0.763). However, in pregnant women who have required hospitalisation, the risk of infection increased five-fold (OR = 4.999; 95% CI = 1.178-21.212). No differences were found between obstetric and perinatal outcomes of both affected and unaffected or treated and untreated cohorts. No teratogenicity was observed at birth. It was concluded that maternal age and 3rd trimester pregnancy were found related to the risk of acquiring H1N1. No differences in obstetric outcomes or worse perinatal outcomes were found in patients affected by the pandemic. Early prophylactic treatment may be related to better maternal-fetal results.