Premature birth

Premature birth is when a baby is born before the normal end of pregnancy. In humans, a pregnancy normally lasts for about nine months or 266 days.

Babies who are born before 37 complete weeks of pregnancy (calculated from the last menstrual period) are said to be premature. In the United States, about 12% of the babies are born prematurely (that is about one in every eight babies).^[1] In 2003, there were over 490,000 premature births.

Worldwide rates of prematurity are more difficult to get. In developing countries, there is often no professional medical care for these babies. This makes it difficult to tell how far along the pregnancy really was. For this reason, the World Health Organization tracks rates of low birth weight instead. In 2000, 16.5% of babies born in developing countries were of low birth weight.^[2] About one-third of these low birth weight deliveries are due to premature delivery.

1. ↑ Martin J.A. et al 2006. Births: final data for 2004. National Vital Statistics Reports. 55, #1.National Center for Health Statistics.
2. ↑ "WHO Data and statistics". Archived from the original on 2007-02-16. Retrieved 2008-09-05.