Science / Medicine : Caution on Pregnancy Tests

Women using home pregnancy tests apparently get incorrect results about 10% of the time because they make mistakes using the tests, raising unfounded hopes and fears, researchers said last week.

Based on a new study evaluating two popular home pregnancy tests, the researchers said the tests themselves are highly accurate when used properly, but they are so complicated that users often produce errors.

“The bottom line is the kits themselves are accurate and perform well. But in the hands of lay people who are not used to doing home testing, many mistakes can be made,” said Jocelyn Hicks, chairwoman of laboratory medicine at Children’s Hospital National Medical Center in Washington. Hicks recommended the tests and instructions be simplified.

Spokesmen for the companies that make the two tests involved in Hicks’ study said they were confident in the accuracy of their products and the clarity of the instructions.

Hicks obtained 200 urine samples from urban adolescents and gave them to a variety of non-technical hospital employees, such as secretaries and janitors, to test with two popular home pregnancy tests. A test, sold as e.p.t. Plus and made by Warner-Lambert Co. of Morris Plains, N.J., produced incorrect results --false positives and false negatives--in 9.5% of the cases. A test called ADVANCE and made by Ortho Pharmaceutical Corp. of Raritan, N.J., produced false results in 12.5% of the cases, the researchers said.