OBJECTIVE: To assess the relationship of preinsertion vaginal ultrasound assessment and menstrual and gynecologic history as predictors of difficult or painful intrauterine device insertion in nulligravid women.
METHODS: Nulligravid women seeking contraception were invited to participate in this nonrandomized study and given the choice between the levonorgestrel-releasing intrauterine system or a copper-releasing intrauterine device. All 165 enrolled women were interviewed and a pelvic examination, including vaginal ultrasonography, was performed before insertion. Insertion difficulties and pain intensity were recorded and assessed against uterine measurements and background characteristics.
RESULTS: Most insertions were assessed as easy (n=144 [89.4%]) and only two (1.2%) failed. Most women had uterine measurements smaller than the studied devices. Odds for difficulties at insertion decreased with every increasing millimeter in total uterine length (odds ratio [OR] 0.86, 95% confidence interval [CI] 0.78–0.96, P=.006) and cervical length (OR 0.85, 95% CI 0.74–0.97, P=.02) and similarly with every decreasing degree of (straighter) flexion angle (OR 0.96, 95% CI 0.94–0.99, P=.005). No absolute threshold measurements could be determined. Still, the majority of insertions in small and flexed uteri were uneventful. Severe insertion pain was common (n=94 [58.4%]). Severe dysmenorrhea was the only predictor of insertion pain (OR 8.16 95% CI 2.56–26.02, P<.001).
CONCLUSION: Ultrasonographic evaluation does not give additional information compared with clinical pelvic examination and sound measure. Although smaller uterine length measurements and steeper flexion angle more often predicted difficulties, the majority of insertions were uneventful in women with small measures. Dysmenorrhea was the only predictor of pain.
CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT01685164.
LEVEL OF EVIDENCE: II
Most intrauterine device insertions are uneventful, but short uterine length and steep flexion angles are associated with insertion difficulties, and dysmenorrhea is associated with painful insertions.
Department of Obstetrics and Gynecology, University of Helsinki, Helsinki University Central Hospital, and Centralized Family Planning, Department of Social Services and Health Care, City of Helsinki, Helsinki, Finland.
Corresponding author: Oskari Heikinheimo, MD, PhD, Department of Obstetrics and Gynecology/Kätilöopisto Hospital, Helsinki University Central Hospital, PO Box 610, 00029-HUS, Helsinki, Finland; e-mail: firstname.lastname@example.org.
Supported by Helsinki University Central Hospital research funds and the Swedish Cultural Foundation in Finland and Nylands Nation who provided funds to Janina Kaislasuo.
Presented in part at the Annual Meeting of the Society for Gynecologic Investigation, March 26–29, 2014, Florence, Italy, and at the Nordic Congress for Obstetricians and Gynecologists, June 9–12, 2014, Stockholm, Sweden.
Financial Disclosure Dr. Suhonen has received lecture fees from Bayer and MSD Finland, and she is a member of the Advisory Board for Contraception MSD Finland. Dr. Heikinheimo serves occasionally on advisory boards for Bayer Healthcare, Gedeon Richter, and MSD/Merck and has designed educational events with these companies. The other authors did not report any potential conflicts of interest.
The authors thank Pasi Korhonen, PhD, Adjunct Professor of Biostatistics, for consultation assistance in statistical testing for uterine measurement analysis.