Table 3.

Pregnancy-Related Claims Within 12 Months of Intrauterine Contraceptive Placement Compared to Tubal Ligation

	Unadjusted incidence rate per 100 woman-years (95% CI)	Unadjusted incident rate ratio (95% CI)	Adjusted* incident rate ratio (95% CI)
Laparoscopic tubal ligation	2.64 (2.43–2.86)	Referent	Referent
Levonorgestrel IUC	2.40 (2.23–2.59)	0.91 (0.82–1.02)	0.72 (0.64–0.82)
Copper IUC	2.99 (2.76–3.24)	1.13 (1.01–1.27)	0.92 (0.82–1.05)

Pregnancy-related claims exclude luteal-phase pregnancies, defined as any pregnancy claims within 30 days following tubal ligation or IUC procedure or any delivery claim within 180 days following the procedure; this study focused on contraceptive procedures performed more than 42 days following any births.

^*Generalized estimating equations for multivariable Poisson regression, adjusted for age group, race/ethnicity, region, year of procedure, endometrial ablation within 7 days of tubal ligation, Medi-Cal program, months of Medi-Cal enrollment in 2 years pre-procedure (log transformed), and baseline health measures (evidenced by claims in 2 years prior to the index contraceptive procedure indicating obesity, pregnancy (categorized as none, ectopic pregnancy, non-ectopic pregnancy), pelvic inflammatory disease, Charlson comorbidity index, and any contraceptive claims. We censored participants from these analyses at the time of any claims for IUC removal, initiation of another form of contraception, pregnancy, or luteal phase, infertility services or consultation, hysterectomy, oophorectomy, or end of data availability on 12/31/2014

Values shown in bold are statistically significant, at the level of p < 0.05