Researchers conducted this study to determine risk factors affecting the incidence of IUD insertion-related complications and failures and, in particular, whether postcoital IUD insertions have a higher incidence of complications than routine IUD insertions.

The study design was retrospective case notes analysis.

The study examined 545 case notes of patients having IUD insertions at East Cheshire NHS Trust family planning clinics between 1 October 1997 and 31 December 2000.

Failed insertions were statistically more likely in women who had never previously had a vaginal delivery and when a less experienced doctor performed the insertion. Nulliparous women were at a statistically increased risk of cervical problems and bradycardia. Cervical problems at insertion also increased significantly with age. Patients who were amenorrhoeic at insertion were more likely to suffer an early IUD expulsion.

The study concluded that of the potential risk factors, nulliparity was the most important. IUD insertion failures and complications were no more common in postcoital than routine IUD insertions. In general, complications were unpredictable, indicating the need for constant vigilance and the inserting doctor being trained and prepared to deal with any difficulty arising.