Teenagers who become pregnant are at a higher risk of further pregnancies in their teenage years, new research suggests.
"Our results clearly demonstrate that young women who become pregnant can be considered a high-risk group for subsequent, unplanned, mistimed, or unwanted pregnancies," said lead researcher Lisa McDaid from University of East Anglia (UEA) in England.
The findings emphasize the importance of embedding preventative actions and behaviors among this group after a birth or abortion, McDaid noted.
The researchers found that nearly a quarter of teenagers in England and Wales who have had an abortion have been pregnant before.
The researchers analyzed national abortion figures for England and Wales from 1992 to 2013, published by the Office of National Statistics and the Department of Health.
In 2013, approximately 23 percent of teenage women having an abortion had been pregnant before.
A minority, less than five percent, had two or more previous pregnancies, though this number almost doubled between 1992 (937) and 2002 (1823).
During the period studied, the number of teenagers having an abortion as a result of a subsequent pregnancy increased by 33 percent, from 5,260 in 1992 to 6,631 in 2013.
Most of this increase took place before 2004 and the figure appears to have stabilized.
The number peaked in 2008, when 9,834 had experienced a previous pregnancy.
McDaniel said that as not all teenage conceptions are first-time conceptions, it had been important to accurately identify the number of teenagers who become pregnant for a second time or more.
The study was published in the Journal of Adolescent Health.