Transvaginal ultrasonographic assessment of the expulsion rate of intrauterine devices inserted in the immediate postpartum period: a pilot study.

Objective: To compare the expulsion rates of intrauterine devices (IUDs) inserted in the immediate postpartum after vaginal birth and cesarean section.

Methods: Nineteen patients who had a vaginal birth and 19 patients who had a cesarean section at Hospital de Clínicas de Porto Alegre, Brazil, were selected for copper T 380A IUD insertion. With the aim of detecting clinically unnoticed dislodged devices, ultrasound examinations were performed at 1 month and between 3 and 12 months after delivery. The IUDs were considered completely expelled when found outside the endometrial cavity (e.g., in the cervical canal) or outside the uterus (in the vagina).

Results: Expulsion rates were statistically different between the two groups: after a vaginal birth, 50% (ultrasound only) + 27.8% (clinical examination); and post-cesarean section, 0% (p < .001; OR 5.75, 95% CI 2.36-14.01).

Conclusion: Considering that the contraceptive efficacy of IUDs is associated with their intrauterine location, the high expulsion rates seen when they are inserted immediately after vaginal delivery contraindicate their use in this setting. The use of IUDs immediately after a cesarean section is still a reasonable alternative because its expulsion rate was zero. Ultrasound assessment of IUD positioning performed better than clinical examination, which failed to detect expulsion after postpartum insertion in 75% of the cases (9 from 12 cases).