In 2007, the most current year for which U.S. birth statistics are available, there was a record number of new children delivered in the country: 4,316,233. The twin birth rate was 32.2 per 1,000 births, or 3.22%. When applied to the overall number of births for the year, this rate translates to 277,965 sets of twins.
Chances of Triplet Births
After rising 70% from 1980 to 2004, the statistical twinning rate has remained constant in 2005, 2006 and 2007. Even more strangely perhaps, the triplet birth rate, which increased some 400% between 1980 and 1998, has since been declining. By way of comparison to the twinning rate, the 2007 statistical rate of triplet births was 148.9 per 1,000, or 14/100th’s of one percent (0.14). The round number out of all this is just 6,042 sets of triplets for the U.S. in 2007.
Preterm Birth Rate
Although the federal government has set the goal of reducing the national pre-term birth rate to 7.6%, the most recent year for which those statistics are available – 2008 – determined that it was actually 12.7%. One of the factors thought to be contributing to this is the higher statistic rate of twin pregnancies, with which come essentially twice the potential complications.
Interesting Twin Fact
At the very other end of the statistical spectrum, historically speaking, are a pair of parents thought to have been the most prolific progenitors for their respective genders. In the 18th century, a Russian woman peasant was reported to have had 69 children over the course of her bearing lifetime. Only two failed to survive, which is remarkable in itself given the era. But the really astonishing statistic of her run as a mother between 1725 and 1765 is the statistical occurrence of twins and triplets. She had 16 pairs of the former, seven pairs of the latter and, reportedly, also four sets of quadruplets.
National Vital Statistics Report – 2010, Retrieved November 23, 2010 from http://www.cdc.gov/nchs/data/nvsr/nvsr58/nvsr58_24.pdf
Business Week – “Still Too Many Preterm Births in U.S., Report Finds”, November 17, 2010, Retrieved November 23, 2010 from http://www.businessweek.com/lifestyle/content/healthday/646077.html
The Guardian – “Making Babies in the 21st Century”, November 5, 2010, Retrieved November 23, 2010 from http://www.guardian.co.uk/commentisfree/audio/2010/nov/04/reproductive-technologies-sex-21st-century
“Can the chance of having twins be modified by diet? [Lancet. 2006] – PubMed result.” National Center for Biotechnology Information. N.p., n.d. Web. 21 Apr. 2010. http://www.ncbi.nlm.nih.gov/pubmed/16679141.
“Multiple Pregnancies.” Utah Department of Health Main Web Site. N.p., n.d. Web. 21 Apr. 2010. http://health.utah.gov/mihp/pregnancy/preged/duringpreg/multiplepreg.htm.
“Twins, Triplets, Multiple Births: MedlinePlus.” National Library of Medicine – National Institutes of Health. N.p., n.d. Web. 21 Apr. 2010. http://www.nlm.nih.gov/medlineplus/twinstripletsmultiplebirths.html.