Getting implanted with Bayer AG’s Essure permanent contraceptive device leaves women at 10% greater risk of requiring post-procedure surgery than undergoing laparoscopic sterilization. This has been revealed by a study published in the British Medical Journal (BMJ) on Tuesday.

The study’s findings might cast significant doubt on the safety of the contraceptive device from the house of Bayer. The device was approved 13 years back (in 2002) as a simpler alternative to surgical sterilization. However, it got acquired by Bayer AG only two years back, in 2013.

Recently, we have seen Essure face a lot of scrutiny from US health regulators following frequent patients complaints and calls demanding the device’s removal from the market.

The study revealed that within a year of undergoing the initial procedure, as much as 2.4% Essure patients had to undergo a post-procedure surgery. The percentage of such operation is as low as 0.2% among patients who underwent laparoscopic sterilization (the least invasive tube-tying process). This means 21 additional surgeries took place for every 1,000 patients implanted with the Bayer device.

The leader of the study Dr, Art Sedrakyan, who teaches healthcare policy and research at the Weill Cornell Medicine, New York, said that small risk imposed on a large number of patients eventually translated into big numbers. He added that in some of the cases the patients required some major surgeries including hysterectomies. For those who don’t know: hysterectomy involves surgical removal of the uterus.

During the study, researchers analyzed coding data offered by medical records of around 52,000 women in New York State’s outpatient ambulatory surgical centers. The said facts and figures were collected between the years 2005 and 2013.

Sedrakyan said that if the data obtained from New York was to be extrapolated for anticipating the situation all through the United States, one would have come across around 150,000 patients undergoing similar post-procedure surgeries.

Here, it must be mentioned that both Essure and laparoscopic sterilization were found to be equally effective. The risk of getting pregnant was found to be 1% among both groups of patients.

Bayer, as expected, has defended the efficacy and safety of its contraceptive device. The company has said that one should not draw any conclusion based on just one database from a single US state.