There, he said, women are paying about $22 per month for prescriptions that cost $10 a few months ago. "Some of our students have two jobs, have children," Jessop said. "To increase this by 100 percent or more overnight, which is what happened, is a huge shock to them and to their system."

At some schools women could see prices rise several hundred dollars per year.

About 39 percent of undergraduate women use oral contraceptives, according to an estimate by the American College Health Association based on survey data.

Many students could shift to generics but experts said they might still pay twice the previous rate.

"It's terrible, because these are students who are working very hard to pay for their tuition and books at a time when tuition costs are edging up as well," said Linda Lekawski, director of the university health center at Texas A&M, where the old price for birth control pills of about $15 per month is expected to triple. "This is one thing they've been able to benefit from for years."

Before the act, pharmaceutical companies supplied the medications to certain health care providers such as universities and public clinics at a heavily discounted price. Now, the incentives for the companies to offer the drugs at the lower prices have been eliminated and without them the companies have removed the discounts rather than maintaining the lower price and taking the loss.

IF YOU have ever sat alone in a bar, depressed by how good-looking everybody else seems to be, take comfort-it may be evolution playing a trick on you. A study just published in Evolution and Human Behavior by Sarah Hill, a psychologist at the University of Texas, Austin, shows that people of both sexes reckon the sexual competition they face is stronger than it really is. She thinks that is useful: it makes people try harder to attract or keep a mate.

Dr Hill showed heterosexual men and women photographs of people. She asked them to rate both how attractive those of their own sex would be to the opposite sex, and how attractive the members of the opposite sex were. She then compared the scores for the former with the scores for the latter, seen from the other side. Men thought that the men they were shown were more attractive to women than they really were, and women thought the same of the women.

Dr Hill had predicted this outcome, thanks to error-management theory-the idea that when people (or, indeed, other animals) make errors of judgment, they tend to make the error that is least costly. The notion was first proposed by Martie Haselton and David Buss, two of Dr Hill's colleagues, to explain a puzzling quirk in male psychology.

Basically, Adjudin nips wannabe sperm cells in the bud. Those cells, called germ cells, ordinarily develop into sperm. But they need the help of other cells, called Sertoli cells, to reach that destiny.

Adjudin interferes with the process.

Cheng's team previously reported from other animal tests that Adjudin, given orally by itself, was too toxic to be a suitable contraceptive because it caused liver inflammation and muscle shrinkage (atrophy).

So the scientists bundled Adjudin with a synthetic version of the sex hormone FSH (follicle-stimulating hormone) and injected it into the bellies of four male rats.

US researchers in Cleveland and New Orleans, and doctors in Mumbai, India, looked at more than 360 men undergoing checks at a fertility clinic who were classified into three groups according to their sperm count.

Men who used a mobile for more than four hours a day had a 25 per cent lower sperm count than men who never used a mobile.

The men with highest usage also had greater problems with sperm quality, with the swimming ability of sperm - a crucial factor in conception - down by a third.

They had a 50 per cent drop in the number of properly formed sperm, with just one-fifth looking normal under a microscope.

Professor Ashok Agarwal, director of the Reproductive Research Centre at the Cleveland Clinic, Ohio, who led the study, said "Almost a billion people are using cell phones around the world and the number is growing in many countries at 20 to 30 per cent a year.