Merck contraceptive spawns 600 pregnancy complaints in U.K.

A Merck ($MRK) birth control implant is drawing fire in the U.K., where about 1,600 women have reported adverse events over the last 10 years, including almost 600 who became pregnant. The Medicines and Healthcare Products Regulatory Agency said that Implanon had been cited in connection with 2,888 suspect reactions in all.

It should be noted that these reports came over the span of a decade, when 1.3 million units of the drug were prescribed, a company spokesman told Dow Jones. "Implanon is more than 99 percent effective," he said, emphasizing the company stands behind the contraceptive's safety and efficacy.

About 800,000 women currently use Implanon, which contains a synthetic progestogen, etonogestrel, Britain's Department of Health told the news service. Besides the unwanted pregnancies, women reported pain at the site of the three-year implant, as well as subsequent scarring.

- read the Dow Jones piece