LONDON (AP) -- A new study calls into question the use of two common infertility treatments for couples who have unexplained problems having children.

Doctors in Scotland tested a drug that stimulates ovulation and artificial insemination against doing nothing in couples who had no obvious reasons for their inability to conceive.

Among the three groups, researchers found little difference in the numbers of couples who had babies. The study was published Friday in the British Medical Journal.

"These treatments are a leap of faith," said Dr. Siladitya Bhattacharya, a professor of reproductive medicine at the University of Aberdeen and the study's lead author. "None of the treatments studied had any significant benefit over no treatment at all."

Infertility affects about one in seven couples. Doctors usually try fertility pills or artificial insemination before moving on to more complicated and expensive techniques like in-vitro fertilization. Bhattacharya said that he and the five study centers no longer offer the two tested treatments for unexplained infertility problems.

A third of the 580 couples in the study were simply counseled on the need to have regular sex. Another group got clomifene citrate, which stimulates the ovaries to release eggs. It is sold as Clomid, Serophene, and Milophene, among other names.

For the third group, doctors performed artificial insemination, injecting sperm into the womb using a syringe.

Women who were pregnant after six months were then monitored until they gave birth.

In the no treatment group, 32 couples had babies. That compares to 26 babies for the women who took fertility pills and 43 for those who had artificial insemination. Experts said the slight differences were not statistically significant.

"It's not in the realm that you would expect it to be if these interventions were really performing," said Allan Pacey, of the University of Sheffield and secretary of the British Fertility Society. He was not linked to the study.

Still, Pacey said that artificial insemination was still useful in certain situations, such as when donor sperm is used.

Fertility drugs like clomifene have long been shown to work in women who have difficulties ovulating. Side effects include nausea, headaches, and hot flashes. It also increases the chance of having twins.

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