Subsequent to the NIH report a large review from the USA of almost 6 million births was published that suggested that neonatal mortality is significantly higher (1.77 vs. 0.62 per 1,000 live births) in babies born by CS. The authors propose that the compression of the fetal lungs during the birthing process may be one of the factors that is beneficial for subsequent survival; this effect is missing when the baby is delivered by CS.[5] A study published in the February 13, 2007 issue of the Canadian Medical Association Journal found that women that have "planned" cesareans had an overall rate of severe complications more than three times that of women that planned vaginal deliveries.[6]