Multiple studies have been performed concerning the safety of home births for both the child and the mother. Standard practices, licensing requirements and access to emergency hospital care differ between regions making it difficult to compare studies across national borders. A 2014 US survey of medical studies found that perinatal mortality rates were triple that of hospital births, and a US nationwide study over 13 million births on a 3-year span (2007–2010) found that births at home were roughly 10 times as likely to be stillborn (14 times in first-born babies) and almost four times as likely to have neonatal seizures or serious neurological dysfunction when compared to babies born in hospitals, while a 2007 UK survey found that perinatal mortality rates were only slightly higher in that country than planned hospital births for low-risk pregnancies. Higher maternal and infant mortality rates are associated with the inability to offer timely assistance to mothers with emergency procedures in case of complications during labour, as well as with widely varying licensing and training standards for birth attendants between different states and countries.