Researchers did this study to assess the incidence of IUDs’ visible strings after post placental insertion following vaginal or cesarean delivery and to establish a management protocol of follow-up visits strings are not visualized.

This prospective study of a cohort of 348 women who underwent post placental insertion of Copper-T 380A IUDs following vaginal or cesarean delivery was conducted in India. All women whose IUD strings could not be pictured at the cervical os were identified at any given follow-up. We analyzed the cumulative incidence of visible lines and procedures to locate the IUD when lines were not visible.

At 1-year follow-up, the IUD was in situ in 313/348 women. There were eight expulsions and 15 IUD removals. Among women with IUDs in situ, the strings were not visible in 73 cases. Pelvic ultrasound confirmed the intrauterine position of the IUDs in these cases. At one year, string visibility was significantly lower after intra-cesarean insertions than vaginal insertions.

The study concluded that the visualization of strings after post placental vaginal insertion is more common than after intra-cesarean insertion. Pelvic ultrasonography can be used to verify the presence of the device in cases of missing strings.

Reference: https://srh.bmj.com/content/43/3/186