It is hypothesized that bladder distension causes the uterine axis to become more aligned with the cervical canal. It has been demonstrated among women undergoing assisted conception that having a full bladder facilitates the passage of an intrauterine catheter.

The researchers did this study to determine if insertion of intrauterine contraceptive devices is easier in women who have a full bladder at the time of insertion.

The sample size consisted of two hundred women requesting intrauterine contraception with a pre-filled bladder. They were randomized to delayed emptying or immediate emptying.

There was no significant difference with reported ease of insertion between the groups. Doctors reported that insertions were either ‘very easy’ or ‘quite easy’ in 82% and 83% of women in the immediate and delayed emptying groups, respectively. There was no significant difference in reported pain scores, with mean pain scores of 3.8 and 4.4 in the delayed and immediate emptying groups, respectively.

The study concluded that bladder filling does not have a significant effect on the ease of insertion of an intrauterine method of contraception. Insertion is mostly associated with low levels of discomfort.