Further to the correspondence between Drs Mansour and Rowlands1 2 and the recent articles about contraceptive implants published in this Journal,3 4 we would like to bring to Journal readers' attention details of a patient who was referred to the Sexual & Reproductive Health Clinic at the Royal Bolton Hospital, Bolton, UK with an impalpable implanon. The patient is in her mid-20s and she had been fitted with an Implanon twice before and had not encountered problems. This, her third Implanon, was inserted in June 2010 by her local family planning clinic and was palpated by both herself and the physician. There was no other significant surgical or medical history. In August 2010, the patient had a dream in which she believed that she had removed the implant. She subsequently could not feel the implant in her arm. She returned to her physician who also could not palpate the Implanon. She was advised to use combined oral contraceptive pills and was referred to the Royal Bolton Hospital. An ultrasound scan and etonogestrel assay were conducted and both were negative. The patient may have in fact removed the implant in her sleep or an intermediary state when perturbed by the foreign body in her arm. This was the interpretation she preferred and believed. Since both the patient and the doctor confirmed that the implant had been palpated when it was inserted this does suggests that in this instance the Implanon had been removed by the patient.

However, had the patient become pregnant, she could have cited incompetence on the part of her physician. An example of the possible consequences is provided by the case of Rees v Darlington Memorial Hospital.5 In this case a pregnancy resulted after a failed sterilisation procedure, and by October 2003 the respondent had been awarded £15 000.

With implant insertion it takes days to weeks for the pierced superficial tissue to reform. Therefore, removal of the Implanon at this time by the patient could be possible. With the implant considered to be immovable, if it is lost or taken out, and a pregnancy results and the Implanon is subsequently discovered not to have failed but to have been absent then the National Health Service (NHS) is liable. The widespread recommendation is that this possibility should be given more attention. In the face of the increasing number of cases of litigation when a pregnancy has resulted, the Medical Defence Union has even posted on its website advice for general practitioners on inserting implants (21 March 2011).6 Recent media coverage may have precipitated part of this trend as there are currently benefits inherent in defrauding the NHS, and currently the service is susceptible.

Precautions must centre on ensuring that the implant was in place to begin with. The level of training given to physicians inserting Implanon should be of a high standard, and perhaps signatures should be obtained from the patients concerned certifying that the implant is present and palpable.

The possibility of the patient removing the implant is a real one and could lead to medico-legal consequences. Further countermeasures should be considered and addressed in the guidelines.