The purpose of the study was to evaluate the pregnancy and complication rates of this new device, with its increased area of copper, compared with other published results, in the clinical setting of British general practice and family planning clinics.

Doctors working in general practice and at family planning clinics throughout the UK who collaborate in the UK Family Planning and Reproductive Health Research Network were responsible for fitting 574 Nova T380® intrauterine contraceptive devices (IUDs). The Nova T® (and formerly the identical Novagard®) IUDs have copper with a surface area of 200 mm2. The Nova T380® has copper with a surface area of 380 mm2.

The study concluded that increased surface area of copper was associated with a reduced pregnancy rate compared to the Nova T®, though no statistical comparison is possible. Although the present study was not a direct comparative study with the Nova T®, the result lends weight to the notion that increasing the copper reduces the pregnancy rate. The discontinuation rate for bleeding problems and bleeding with pain and the expulsion rates were higher than in published Nova T® studies.

Reference: https://srh.bmj.com/content/28/2/69