Females, particularly in developing countries, tend to have higher rates of obesity [77] . According to the WHO, in 138 of 195 countries, females are over 50% more likely to be obese than males [78] . In some countries, the body mass index for women is 5-8 points higher than for men [78] . The higher rates of obesity and diabetes in females may be significant factors contributing to higher 2009 H1N1-related morbidity in women. It has not yet been determined whether prepregnancy obesity or excess weight gain during pregnancy represent equivalent risks. Precise parameters for documenting obesity in pregnant women have not been established [79] .