Uterine Length in Adolescents with Developmental Disability: Are Ultrasound Examinations Necessary before Insertion of the Levonorgestrel Intrauterine System?

Abstract Study Objective (1) To determine if there are any differences in uterine length between adolescents with developmental disability (DD) compared with their normally developing (ND) peers that might necessitate ultrasonography before insertion of levonorgestrel intrauterine system (LNG-IUS) in patients with DD; and (2) to characterize the LNG-IUS insertion procedure in adolescents with disabilities. Design, Setting, Participants, and Interventions This was a retrospective cohort study of 223 female adolescents with or without DDs. Seventy-five adolescents had DD; 33 underwent intrauterine system insertion in the operating room and 42 did not. A comparative cohort of 148 ND adolescents who had pelvic ultrasound examinations for abnormal uterine bleeding were included. The study period was between January 2006 and July 2013 at the Hospital for Sick Children, Toronto, Canada. Cases were identified from surgical databases and medical records. Main Outcome Measures Mean uterine length on pelvic ultrasound, demographic characteristics (age, age at menarche, time from menarche to ultrasound, weight), and descriptive statistics on intrauterine system insertion. Results There was a statistically significant difference ( P  = .03) in uterine length between adolescents with and without DD (6.7 vs 7.1 cm). However, this was not a clinically significant difference because insertion of the LNG-IUS in patients with DD was successful in patients with uteri more than 5 cm long. There was no difference ( P  = .97) in uterine length of adolescents with DD whether they had LNG-IUS insertion or not (6.7 cm). Adolescents with DD were younger than adolescents without DD at time of ultrasound examination ( P  = .01). However, among patients with DD, those who underwent intrauterine system insertion were older ( P  = .001). Incidence of uterine anomaly in patients with DD is low (2.7%) and was the same as in ND adolescents. Rates of complications and expulsions were low and there were no failures of LNG-IUS insertion in adolescents with DD. Conclusion Routine pelvic ultrasound examinations are not necessary before insertion of the LNG-IUS for menstrual suppression in adolescents with DD. Renal abnormalities, obstructive symptoms, and very small stature might necessitate imaging. Insertion using anesthesia is often straightforward and successful with minimal complications.