WEDNESDAY, March 8 (HealthDay News) — Since January 2000, Texas state law has mandated that doctors notify the parents of any girl under the age of 18 seeking an abortion at least 48 hours before the procedure.

Similar laws, all hotly contested, exist in one form or another in 34 states.

Now, one of the most rigorously conducted studies to date on the issue of parental notification finds that the rate of teen abortions in Texas dropped by 11 percent among 15-year-olds, 20 percent among 16-year-olds, and 16 percent among 17-year-olds in the first two years after the bill was enacted.

The study, published in the March 9 issue of the New England Journal of Medicine, uncovered another phenomenon: After Texas introduced the parental notification law, rates for late-term (after 12 weeks’ gestation) abortion rose among girls who were a few months shy of their 18th birthday at the time of conception.

According to the study authors, this suggests that many were waiting till they reached that milestone so they could legally have the procedure without informing their parents.

The seo services analysis is based on state records of approximately 14,000 abortions and 65,000 births per year involving 15- to 19-year-old Texan girls. The study compares changes in teen births and abortions between the years 1998-1999 (two years before the parental notification law went into effect) and 2000-2002 (two years after).

The take-home message is clear: “These comparisons suggest that the laws are causing kids to have fewer abortions and carry their pregnancies to term,” said lead researcher Ted Joyce, a professor of economics at Baruch College, part of the City College of New York.

The findings come on the heels of a similar, six-state review by The New York Times that was published Monday. Unlike the Texas study, the Times analysis found no clear pattern — only a “scattering of divergent trends,” with abortion rates rising in some states after laws were passed, but falling in others.

Joyce’s Texas study is less ambiguous, finding a legislation-linked trend toward fewer abortions. Not surprisingly, reaction to the results depends on one’s view on abortion.

“This study validates that parental notification laws are having a positive effect in reducing the number of abortions,” said Wendy Wright, executive vice president of the Washington, D.C.-based conservative group Concerned Women for America. Wright said the Texas law, and similar legislation elsewhere, is just “one element of an overall cultural shift that disfavors abortion.”

On the other hand, Danielle Tierney, director of public affairs for Planned Parenthood of Austin, Texas, said most of the decline in abortions noted in the study can probably be explained by national trends toward fewer teen pregnancies and the increased use of emergency contraception.

At the same time, however, “we are concerned about the inherent dangers posed by parental notification laws,” Tierney said. She said her group is particularly troubled by the laws’ effect “on teens who don’t come from model families — where there might be abuse, or simply the lack of a responsible adult or parent in a teen’s life.”

According to Joyce, the new study is an improvement on earlier efforts because it stops comparing “apples and oranges.” In the past, he said, it had been tough to figure out how legislation affected teen abortion rates because younger teens (such as 15- and 16-year-olds) think and act very differently than 18-year-olds — the usual group studied.

“So, what we did — because Texas is such a big state — is we had the numbers to compare kids who are 17-and-6-months of age at the time of conception, to those who are 18-and-3-months at the time of conception,” he said. Not only does this “tighte