At least half of the babies born to teenage girls are fathered by adults, according to a new national study by the Alan Guttmacher Institute.
The study, which many researchers said is the most comprehensive of its kind, implies that a startling number of teenage girls are having sex with men who are breaking state statutory rape laws.Some family-planning experts said the study also demonstrated that pregnancy-prevention programs, many of them in schools, fail to reach many of those responsible for unplanned pregnancies.
Drawing from a survey of nearly 10,000 mothers between ages 15 and 49 who were interviewed from 1989 to 1991, researchers found that half of the fathers of babies born to mothers between ages 15 and 17 were 20 or older and that 20 percent of the fathers were six or more years older. In general, the survey found, the younger a mother was, the greater the age difference between her and her partner.
"To most people, these numbers are counterintuitive," said David J. Landry, a co-author of the study and a senior research associate at the institute, based in New York. "This research highlights that teenage pregnancy is not just limited to teenagers but that in fact adult males bear a lot of the responsibility."
The sample base for the study, to be published on Thursday in Family Planning Perspectives, a publication of the institute, came from a survey by the National Center for Health Statistics, which interviewed mothers between 1989 and 1991.
The research supports recent data that found similar patterns on state levels. For example, a California survey of 47,000 births to teenage mothers in 1993 found that two-thirds of the babies were fathered by men who were of post-high-school age. With high school girls, fathers tended to be an average of 4.2 years older than their partners, and with mothers in junior high school, they were on average 6.7 years older.
In most states, including New York, rarely applied laws of consent prohibit people 18 or older from having sex with those under 16, and punishment is generally greater with the breadth of age difference. (In California, the age of consent is 18.)
"One begins to see the fact that this is sexual abuse among many of these teenagers," said Mike Males, a graduate student at the University of California at Irvine and a co-author of the California survey with his adviser, Kenneth S.Y. Chew.
Indeed, their study found that among California mothers ages 11 to 15, only 9 percent of their partners were other junior high school boys. Forty percent of the fathers were high school boys, and 51 percent were adults, it found.