Couples having trouble conceiving a baby may not have much better luck when they use common fertility treatments, according to a study in BMJ.

A team from the University of Aberdeen found 850 women who had trouble getting pregnant without an obvious expectation. They were placed randomly into three groups, one that continued trying with no medical intervention; one that used clomifene citrate, often known as Clomid; and one that tried artificial insemination without stimulating the ovaries.

Overall, 101 women became pregnant and had a live birth during the course of the study.

The live birth rate among the group that tried naturally was 17 percent. For those on Clomid, it was 14 percent. For those on artificial insemination, it was 23 percent.

The researchers said in a news release that to show any meaningful gains, the difference would have to be more than 6 percent.

But, women who were receiving either of the two treatments said they felt reassured by the process.

"These interventions, which have been in use for many years, are unlikely to be more effective than no treatment," the researchers wrote.