Risk Factors Associated with Outcomes of Seasonal Influenza in Pregnant Women Referring to Healthcare Centers in Iran in 2015 - 2016

Influenza causes high mortality rate among pregnant women, while morbidity and mortality cases of this disease and its side effects among pregnant women can be simply prevented by vaccination and reducing risk factors such as cardiovascular diseases, diabetes, hypertension, etc.

Hence, this study was conducted to investigate the risk factors and mortality rate of seasonal influenza among pregnant women referring to healthcare centers in Iran during 2015 - 2016.

This case-control study was conducted to examine the odds ratio of seasonal influenza among pregnant women with seasonal influenza who had referred to all healthcare centers in Iran with severe respiratory disease symptoms during 2015-2016. The statistical population consisted of 2,080 pregnant women of whom, 24 dead women constituted the case group and 100 randomly selected living women constituted the control group. A researcher-made checklist was used for data collection. The collected data were analyzed using the statistical test of the odds ratio with SPSS-22 software.

Mean (standard deviation) of age was 31 (2.3) and 34 (3.8) in living and dead pregnant women, respectively. The most frequent type of conflicting influenza virus was H1N1 in both case and control groups (83% and 71%, respectively). There was a significant difference between case and control groups in the risk factors including diabetes (P = 0.003), blood pressure (P = 0.001), obesity (P = 0.026), cardiovascular diseases (P = 0.001), renal diseases (P = 0.013), and respiratory diseases (P = 0.012). Among these risk factors, the highest odds ratio (OR) was related to cardiovascular diseases (OR = 24), blood pressure (OR = 16.3), and diabetes (OR = 12.9), in sequence. Oseltamivir prescribed to all patients in the control group and 92% of patients in the case group. Seven patients in the control group and none in the case group had a history of influenza vaccination.

It is necessary to take steps and underpin training programs to reduce the risk factors of seasonal influenza among pregnant women based on the national vaccination guidelines.