Characteristics and hormonal contraception use patterns of levonorgestrel 13.5 mg intrauterine device users in Sweden 2014-2016.

OBJECTIVES: The levonorgestrel-releasing intrauterine device containing 13.5 mg of levonorgestrel (LNG 13.5 mg IUD), Jaydess, was approved for contraception by the European Medicines Agency in 2013. We aimed to describe the characteristics of new users of LNG 13.5 mg IUD in Sweden within the first 3 years after approval (2014-2016). STUDY DESIGN: We conducted an observational, population-based study using data from the Swedish national registers. Women with the first pharmacy dispensation of LNG 13.5 mg IUD between 2014 and 2016 were followed until December 31, 2020. Descriptive analyses included demographic characteristics, duration of the use of first-time LNG 13.5 mg IUD, and contraceptive switching patterns. RESULTS: We included 38,327 women, with mean age at first-time LNG 13.5 mg IUD use of 26 (SD: 7) years. Over 80% were prescribed LNG 13.5 mg IUD by a midwife. The most common comorbidities in the year prior to LNG 13.5 mg IUD use (2%-3% prevalence) were depression, anxiety, premenstrual syndrome, and menorrhagia. The median duration of first-time LNG 13.5 mg IUD use was 2.6 years, and after use, more than 50% of women opted to continue using a hormonal intrauterine device. CONCLUSIONS: In this postmarketing drug utilization study, there were over 38,000 first-time LNG 13.5 mg IUD users in Sweden between 2014 and 2016, with an estimated median duration of use of 2.6 years. First-time LNG 13.5 mg IUD users consisted mostly of young, healthy individuals with a history of hormonal contraceptive use. Over half of the women continued using a hormonal IUD after the first LNG 13.5 mg IUD. IMPLICATIONS: The median duration of LNG 13.5 mg IUD use was 2.6 years, approaching the 3-year indicated use limit. The majority of users continued with another hormonal intrauterine device after LNG 13.5 mg IUD use.

Risks of Uterine Perforation and Expulsion Associated With Intrauterine Devices.

OBJECTIVE: The APEX-IUD (Association of Perforation and Expulsion of Intrauterine Devices) study evaluated the association of postpartum timing of intrauterine device (IUD) insertion, breastfeeding, heavy menstrual bleeding, and IUD type (levonorgestrel-releasing vs copper) with risks of uterine perforation and IUD expulsion in usual clinical practice. We summarize the clinically important findings to inform counseling and shared decision making. METHODS: APEX-IUD was a real-world (using U.S. health care data) retrospective cohort study of individuals aged 50 years and younger with IUD insertions between 2001 and 2018 and with electronic health record data. Cumulative incidences of uterine perforation and IUD expulsion were calculated. Adjusted hazard ratios (aHRs) and 95% CIs were estimated from proportional hazards models with control of confounding. RESULTS: Among the study population of 326,658, absolute risk of uterine perforation was low overall (cumulative incidence, 0.21% [95% CI 0.19-0.23%] at 1 year and 0.61% [95% CI 0.56-0.66% at 5 years]) but was elevated for IUDs inserted during time intervals within 1 year postpartum, particularly among those between 4 days and 6 weeks postpartum (aHR 6.71, 95% CI 4.80-9.38), relative to nonpostpartum insertions. Among postpartum insertions, IUD expulsion risk was greatest for insertions in the immediate postpartum period (0-3 days after delivery) compared with nonpostpartum (aHR 5.34, 95% CI 4.47-6.39). Postpartum individuals who were breastfeeding had a slightly elevated risk of perforation and lowered risk of expulsion than those not breastfeeding. Among nonpostpartum individuals, those with a heavy menstrual bleeding diagnosis were at greater risk of expulsion than those without (aHR 2.84, 95% CI 2.66-3.03); heavy menstrual bleeding also was associated with a slightly elevated perforation risk. There was a slightly elevated perforation risk and slightly lower expulsion risk associated with levonorgestrel-releasing IUDs compared with copper IUDs. CONCLUSION: Absolute risk of adverse outcomes with IUD insertion is low. Clinicians should be aware of the differences in risks of uterine perforation and expulsion associated with IUD insertion during specific postpartum time periods and with a heavy menstrual bleeding diagnosis. This information should be incorporated into counseling and decision making for patients considering IUD insertion. FUNDING SOURCE: Bayer AG. CLINICAL TRIAL REGISTRATION: EU PAS register, EUPAS33461.

Utilisation, effectiveness, and safety of immediate postpartum intrauterine device insertion: a systematic literature review.

BACKGROUND: Intrauterine devices (IUDs) are highly effective contraception. IUDs inserted directly following delivery provide immediate birth control and may decrease unintended pregnancies, including short-interval pregnancies, thereby mitigating health risks and associated economic burden. METHODS: This systematic literature review included published global data on the utilisation, effectiveness, and safety of postpartum intrauterine devices (PPIUDs) of any type. English language articles indexed in MEDLINE, Embase, and Cochrane from January 2010-October 2021 were included. RESULTS: 133 articles met the inclusion criteria (46% interventional studies; 54% observational; n=87 from lower-income countries; n=46 from higher-income countries). PPIUD use was low in higher-income countries (6/10 000 US deliveries in 2013-2016) and varied widely in lower-income countries (2%-46%). Across both higher- and lower-income countries, in most studies (79%), >80% of women with PPIUDs had an IUD in place by 3 months; at 6 and 12 months, 76% and 54% of included studies reported that >80% of women had an IUD in place; reason for discontinuation was infrequently reported. Pregnancies were rare (96 pregnancies across 12 191 women from 37 studies reporting data) and were generally unrelated to device failure, but rather occurred in women no longer using a PPIUD. Expulsions occurred mainly in the early outpatient period and ranged widely (within 3 months: 0-41%). Abnormal bleeding, infections, or perforations were rare. CONCLUSIONS: PPIUDs are safe and effective. Long-term follow-up data are limited. Future research elucidating reasons underlying lack of PPIUD use is warranted.

Demographic, Reproductive, and Medical Risk Factors for Intrauterine Device Expulsion.

OBJECTIVE: To explore to what extent intrauterine device (IUD) expulsion is associated with demographic and clinical risk factors. METHODS: The APEX-IUD (Association of Perforation and Expulsion of IntraUterine Devices) study was a U.S. cohort study using electronic health records from three integrated health care systems (Kaiser Permanente Northern California, Southern California, and Washington) and a health care information exchange (Regenstrief Institute). These analyses included individuals aged 50 years or younger with IUD insertions from 2001 to 2018. Intrauterine device expulsion cumulative incidence and incidence rates were estimated. Using Cox regression models, hazard ratios with 95% CIs were estimated before and after adjustment for risk factors of interest (age, race and ethnicity, parity, body mass index [BMI], heavy menstrual bleeding, and dysmenorrhea) and potential confounders. RESULTS: In total, 228,834 individuals with IUD insertion and no delivery in the previous 52 weeks were identified (184,733 [80.7%] with levonorgestrel-releasing intrauterine system). Diagnosis of heavy menstrual bleeding-particularly a diagnosis in both recent and past periods-was the strongest risk factor for IUD expulsion. Categories with the highest risk of IUD expulsion within each risk factor included individuals diagnosed with overweight, obesity, and morbid obesity; those in younger age groups, especially among those aged 24 years or younger; and in those with parity of four or more. Non-Hispanic White individuals had the lowest incidence and risk, and after adjustment, Asian or Pacific Islander individuals had the highest risk. Dysmenorrhea was not independently associated with expulsion risk when adjusting for heavy menstrual bleeding. CONCLUSION: Most risk factors for expulsion identified in this study appear consistent with known physiologic factors that affect uterine anatomy and physiology (age, BMI, heavy menstrual bleeding, parity). The increased risk of IUD expulsion among individuals of color warrants further investigation. Intrauterine devices are an effective long-term contraceptive; expulsion is uncommon, but patients should be counseled accordingly. FUNDING SOURCE: Bayer AG. CLINICAL TRIAL REGISTRATION: EU PAS register, EUPAS33461.

Intrauterine device-related uterine perforation incidence and risk (APEX-IUD): a large multisite cohort study.

BACKGROUND: Reports of perforation risk related to intrauterine devices (IUDs) inserted immediately post partum and among non-post-partum individuals are scarce, and previous studies with only 12-month follow-ups underestimate the risk. Breastfeeding at IUD insertion and insertion within 36 weeks post partum have been associated with increased risk of uterine perforation. The aim of these analyses was to compare the incidence and risks of IUD-related uterine perforations by non-post-partum and post-partum intervals at IUD insertion, and among post-partum individuals, to assess the impact of breastfeeding on these outcomes. METHODS: We did a multisite cohort study in the USA, using electronic health records (EHR). Study sites were three health-care systems and a site that used data from a health-care information exchange. The study population included individuals who were aged 50 years or younger and had an IUD insertion between Jan 1, 2001, and April 30, 2018. Individuals were excluded if they had not been in the health-care system for at least 12 months before IUD insertion. The primary outcome for this analysis was any IUD-related uterine perforation diagnosis for the first IUD insertion in this time period. Both complete and partial IUD-related perforations were identified. Chart abstraction was done to validate EHR-based algorithms or confirm perforations. The crude rate and cumulative incidence of uterine perforation were evaluated by non-post-partum and post-partum intervals at IUD insertion in the full cohort, and by breastfeeding status in a subcohort of post-partum individuals. Cox models estimated crude and adjusted hazard ratios (aHRs). FINDINGS: Data from 326 658 individuals in the full cohort and 94 817 individuals in the post-partum subcohort were analysed. In the full cohort, we identified 1008 uterine perforations (51·2% complete), with the 5-year cumulative incidence being the lowest in the non-post-partum group (0·29%, 95% CI 0·26-0·34). The aHR for the post-partum interval relative to non-post partum ranged from 2·73 (95% CI 1·33-5·63; 0 to 3 days post partum) to 6·71 (4·80-9·38; 4 days to ≤6 weeks post partum). The post-partum subcohort of individuals with breastfeeding information had 673 uterine perforations (62% complete), with a 5-year cumulative incidence of 1·37% (95% CI 1·24-1·52) and an increased risk with breastfeeding (aHR 1·37, 95% CI 1·12-1·66). INTERPRETATION: Although the risk for uterine perforation with IUD insertion 4 days to 6 weeks or less post partum is nearly seven times that of insertion non-post partum, perforation remains an incredibly rare event for all clinical time points. Despite a slight increased risk of perforation with breastfeeding at IUD insertion, the benefits of breastfeeding and effective contraception generally outweigh risks and should have little clinical impact. Therefore, IUD insertion timing should be based on individual desire for IUD contraception and patient convenience to assure an IUD insertion can occur. Careful follow-up of individuals at higher risk of uterine perforation is warranted. FUNDING: Bayer AG.

Association between intrauterine device type and risk of perforation and device expulsion: results from the Association of Perforation and Expulsion of Intrauterine Device study.

BACKGROUND: Intrauterine devices, including levonorgestrel-releasing and copper devices, are highly effective long-acting reversible contraceptives. The potential risks associated with intrauterine devices are low and include uterine perforation and device expulsion. OBJECTIVE: This study aimed to evaluate the risk of perforation and expulsion associated with levonorgestrel-releasing devices vs copper devices in clinical practice in the United States. STUDY DESIGN: The Association of Perforation and Expulsion of Intrauterine Device study was a retrospective cohort study of women aged ≤50 years with an intrauterine device insertion during 2001 to 2018 and information on intrauterine device type and patient and medical characteristics. Of note, 4 research sites with access to electronic health records contributed data for the study: 3 Kaiser Permanente-integrated healthcare systems (Northern California, Southern California, and Washington) and 1 healthcare system using data from a healthcare information exchange in Indiana (Regenstrief Institute). Perforation was classified as any extension of the device into or through the myometrium. Expulsion was classified as complete (not visible in the uterus or abdomen or patient reported) or partial (any portion in the cervix or malpositioned). We estimated the crude incidence rates and crude cumulative incidence by intrauterine device type. The risks of perforation and expulsion associated with levonorgestrel-releasing intrauterine devices vs copper intrauterine devices were estimated using Cox proportional-hazards regression with propensity score overlap weighting to adjust for confounders. RESULTS: Among 322,898 women included in this analysis, the incidence rates of perforation per 1000 person-years were 1.64 (95% confidence interval, 1.53-1.76) for levonorgestrel-releasing intrauterine devices and 1.27 (95% confidence interval, 1.08-1.48) for copper intrauterine devices; 1-year and 5-year crude cumulative incidence was 0.22% (95% confidence interval, 0.20-0.24) and 0.63% (95% confidence interval, 0.57-0.68) for levonorgestrel-releasing intrauterine devices and 0.16% (95% confidence interval, 0.13-0.20) and 0.55% (95% confidence interval, 0.44-0.68) for copper intrauterine devices, respectively. The incidence rates of expulsion per 1000 person-years were 13.95 (95% confidence interval, 13.63-14.28) for levonorgestrel-releasing intrauterine devices and 14.08 (95% confidence interval, 13.44-14.75) for copper intrauterine devices; 1-year and 5-year crude cumulative incidence was 2.30% (95% confidence interval, 2.24-2.36) and 4.52% (95% confidence interval, 4.40-4.65) for levonorgestrel-releasing intrauterine devices and 2.30% (95% confidence interval, 2.18-2.44) and 4.82 (95% confidence interval, 4.56-5.10) for copper intrauterine devices, respectively. Comparing levonorgestrel-releasing intrauterine devices with copper intrauterine devices, the adjusted hazard ratios were 1.49 (95% confidence intervals, 1.25-1.78) for perforation and 0.69 (95% confidence intervals, 0.65-0.73) for expulsion. CONCLUSION: After adjusting for potential confounders, levonorgestrel-releasing intrauterine devices were associated with an increased risk of uterine perforation and a decreased risk of expulsion relative to copper intrauterine devices. Given that the absolute numbers of these events are low in both groups, these differences may not be clinically meaningful.

Association between menorrhagia and risk of intrauterine device-related uterine perforation and device expulsion: results from the Association of Uterine Perforation and Expulsion of Intrauterine Device study.

BACKGROUND: Intrauterine devices are effective instruments for contraception, and 1 levonorgestrel-releasing device is also indicated for the treatment of heavy menstrual bleeding (menorrhagia). OBJECTIVE: To compare the incidence of intrauterine device expulsion and uterine perforation in women with and without a diagnosis of menorrhagia within the first 12 months before device insertion STUDY DESIGN: This was a retrospective cohort study conducted in 3 integrated healthcare systems (Kaiser Permanente Northern California, Southern California, and Washington) and a healthcare information exchange (Regenstrief Institute) in the United States using electronic health records. Nonpostpartum women aged ≤50 years with intrauterine device (eg, levonorgestrel or copper) insertions from 2001 to 2018 and without a delivery in the previous 12 months were studied in this analysis. Recent menorrhagia diagnosis (ie, recorded ≤12 months before insertion) was ascertained from the International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification codes. The study outcomes, viz, device expulsion and device-related uterine perforation (complete or partial), were ascertained from electronic medical records and validated in the data sources. The cumulative incidence and crude incidence rates with 95% confidence intervals were estimated. Cox proportional hazards models estimated the crude and adjusted hazard ratios using propensity score overlap weighting (13-16 variables) and 95% confidence intervals. RESULTS: Among 228,834 nonpostpartum women, the mean age was 33.1 years, 44.4% of them were White, and 31,600 (13.8%) had a recent menorrhagia diagnosis. Most women had a levonorgestrel-releasing device (96.4% of those with and 78.2% of those without a menorrhagia diagnosis). Women with a menorrhagia diagnosis were likely to be older, obese, and have dysmenorrhea or fibroids. Women with a menorrhagia diagnosis had a higher intrauterine device-expulsion rate (40.01 vs 10.92 per 1000 person-years) than those without, especially evident in the first few months after insertion. Women with a menorrhagia diagnosis had a higher cumulative incidence (95% confidence interval) of expulsion (7.00% [6.70-7.32] at 1 year and 12.03% [11.52-12.55] at 5 years) vs those without (1.77% [1.70-1.84] at 1 year and 3.69% [3.56-3.83] at 5 years). The risk of expulsion was increased for women with a menorrhagia diagnosis vs for those without (adjusted hazard ratio, 2.84 [95% confidence interval, 2.66-3.03]). The perforation rate was low overall (<1/1000 person-years) but higher in women with a diagnosis of menorrhagia vs in those without (0.98 vs 0.63 per 1000 person-years). The cumulative incidence (95% confidence interval) of uterine perforation was slightly higher for women with a menorrhagia diagnosis (0.09% [0.06-0.14] at 1 year and 0.39% [0.29-0.53] at 5 years) than those without it (0.07% [0.06-0.08] at 1 year and 0.28% [0.24-0.33] at 5 years). The risk of perforation was slightly increased in women with a menorrhagia diagnosis vs in those without (adjusted hazard ratio, 1.53; 95% confidence interval, 1.10-2.13). CONCLUSION: The risk of expulsion is significantly higher in women with a recent diagnosis of menorrhagia. Patient education and counseling regarding the potential expulsion risk is recommended at insertion. The absolute risk of perforation for women with a recent diagnosis of menorrhagia is very low. The increased expulsion and perforation rates observed are likely because of causal factors of menorrhagia.

Association of the Timing of Postpartum Intrauterine Device Insertion and Breastfeeding With Risks of Intrauterine Device Expulsion.

IMPORTANCE: Intrauterine device (IUD) expulsion increases the risk of unintended pregnancy; how timing of postpartum IUD insertion and breastfeeding are associated with risk of expulsion is relevant to the benefit-risk profile. OBJECTIVE: To evaluate the association of postpartum timing of IUD insertion and breastfeeding status with incidence and risk of IUD expulsion. DESIGN, SETTING, AND PARTICIPANTS: The Association of Perforation and Expulsion of Intrauterine Devices (APEX-IUD) cohort study included women aged 50 years or younger with an IUD insertion between 2001 and 2018. The breastfeeding analysis focused on a subcohort of women at 52 or fewer weeks post partum with known breastfeeding status. The study was conducted using data from electronic health records (EHRs) at 4 research sites with access to EHR: 3 Kaiser Permanente sites (Northern California, Southern California, Washington) and the Regenstrief Institute (Indiana). Data analysis was conducted from June to November 2019. EXPOSURES: Timing of IUD insertion post partum was categorized into discrete time periods: 0 to 3 days, 4 days to 6 or fewer weeks, more than 6 weeks to 14 or fewer weeks, more than 14 weeks to 52 or fewer weeks, and non-post partum (>52 weeks or no evidence of delivery). Breastfeeding status at the time of insertion was determined from clinical records, diagnostic codes, or questionnaires from well-baby visits. MAIN OUTCOMES AND MEASURES: Incidence rates and adjusted hazard ratios (aHRs) were estimated using propensity scores to adjust for confounding. RESULTS: The full cohort included 326 658 women (mean [SD] age, 32.0 [8.3] years; 38 911 [11.9%] Asian or Pacific Islander; 696 [0.2%] Hispanic Black; 56 180 [17.2%] Hispanic other; 42 501 [13.0%] Hispanic White; 28 323 [8.7%] non-Hispanic Black; 137 102 [42.0%] non-Hispanic White), and the subcohort included 94 817 women. Most IUDs were levonorgestrel-releasing (259 234 [79.4%]). There were 8943 expulsions. The 5-year cumulative incidence of IUD expulsion was highest for insertions 0 to 3 days post partum (10.73%; 95% CI, 9.12%-12.61%) and lowest for insertions more than 6 weeks to 14 or fewer weeks post partum (3.18%; 95% CI, 2.95%-3.42%). Adjusted HRs using women with non-post partum IUD insertion as the referent were 5.34 (95% CI, 4.47-6.39) for those with postpartum insertion at 0 to 3 days; 1.22 (95% CI, 1.05-1.41) for those with postpartum insertion at 4 days to 6 or fewer weeks; 1.06 (95% CI, 0.95-1.18) for those with postpartum insertion at more than 6 to 14 or fewer weeks; and 1.43 (95% CI, 1.29-1.60) for those with postpartum insertion at more than 14 to 52 or fewer weeks. In the subcohort, 5-year cumulative incidence was 3.49% (95% CI, 3.25%-3.73%) for breastfeeding women and 4.57% (95% CI, 4.22%-4.95%) for nonbreastfeeding women; the adjusted HR for breastfeeding vs not breastfeeding was 0.71 (95% CI, 0.64-0.78). CONCLUSIONS AND RELEVANCE: In this study of real-world data, IUD expulsion was rare but more common with immediate postpartum insertion. Breastfeeding was associated with lower expulsion risk.

Design of the Association of Uterine Perforation and Expulsion of Intrauterine Device study: a multisite retrospective cohort study.

BACKGROUND: Intrauterine devices are effective and safe, long-acting reversible contraceptives, but the risk of uterine perforation occurs with an estimated incidence of 1 to 2 per 1000 insertions. The European Active Surveillance Study for Intrauterine Devices, a European prospective observational study that enrolled 61,448 participants (2006-2012), found that women breastfeeding at the time of device insertion or with the device inserted at ≤36 weeks after delivery had a higher risk of uterine perforation. The Association of Uterine Perforation and Expulsion of Intrauterine Device (APEX-IUD) study was a Food and Drug Administration-mandated study designed to reflect current United States clinical practice. The aims of the APEX-IUD study were to evaluate the risk of intrauterine device-related uterine perforation and device expulsion among women who were breastfeeding or within 12 months after delivery at insertion. OBJECTIVE: We aimed to describe the APEX-IUD study design, methodology, and analytical plan and present population characteristics, size of risk factor groups, and duration of follow-up. STUDY DESIGN: APEX-IUD study was a retrospective cohort study conducted in 4 organizations with access to electronic health records: Kaiser Permanente Northern California, Kaiser Permanente Southern California, Kaiser Permanente Washington, and Regenstrief Institute in Indiana. Variables were identified through structured data (eg, diagnostic, procedural, medication codes) and unstructured data (eg, clinical notes) via natural language processing. Outcomes include uterine perforation and device expulsion; potential risk factors were breastfeeding at insertion, postpartum timing of insertion, device type, and menorrhagia diagnosis in the year before insertion. Covariates include demographic characteristics, clinical characteristics, and procedure-related variables, such as difficult insertion. The first potential date of inclusion for eligible women varies by research site (from January 1, 2001 to January 1, 2010). Follow-up begins at insertion and ends at first occurrence of an outcome of interest, a censoring event (device removal or reinsertion, pregnancy, hysterectomy, sterilization, device expiration, death, disenrollment, last clinical encounter), or end of the study period (June 30, 2018). Comparisons of levels of exposure variables were made using Cox regression models with confounding adjusted by propensity score weighting using overlap weights. RESULTS: The study population includes 326,658 women with at least 1 device insertion during the study period (Kaiser Permanente Northern California, 161,442; Kaiser Permanente Southern California, 123,214; Kaiser Permanente Washington, 20,526; Regenstrief Institute, 21,476). The median duration of continuous enrollment was 90 (site medians 74-177) months. The mean age was 32 years, and the population was racially and ethnically diverse across the 4 sites. The mean body mass index was 28.5 kg/m2, and of the women included in the study, 10.0% had menorrhagia ≤12 months before insertion, 5.3% had uterine fibroids, and 10% were recent smokers; furthermore, among these women, 79.4% had levonorgestrel-releasing devices, and 19.5% had copper devices. Across sites, 97,824 women had an intrauterine device insertion at ≤52 weeks after delivery, of which 94,817 women (97%) had breastfeeding status at insertion determined; in addition, 228,834 women had intrauterine device insertion at >52 weeks after delivery or no evidence of a delivery in their health record. CONCLUSION: Combining retrospective data from multiple sites allowed for a large and diverse study population. Collaboration with clinicians in the study design and validation of outcomes ensured that the APEX-IUD study results reflect current United States clinical practice. Results from this study will provide valuable information based on real-world evidence about risk factors for intrauterine devices perforation and expulsion for clinicians.

Identification and validation of uterine perforation, intrauterine device expulsion, and breastfeeding in four health care systems with electronic health records.

OBJECTIVE: To validate algorithms identifying uterine perforations and intrauterine device (IUD) expulsions and to ascertain availability of breastfeeding status at the time of IUD insertion. STUDY DESIGN AND SETTING: Four health care systems with electronic health records (EHRs) participated: Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA), and Regenstrief Institute (RI). The study included women ≤50 years of age with an IUD insertion. Site-specific algorithms using structured and unstructured data were developed and a sample validated by EHR review. Positive predictive values (PPVs) of the algorithms were calculated. Breastfeeding status was assessed in a random sample of 125 women at each research site with IUD placement within 52 weeks postpartum. RESULTS: The study population included 282,028 women with 325,582 IUD insertions. The PPVs for uterine perforation were KPNC 77%, KPSC 81%, KPWA 82%, and RI 47%; PPVs for IUD expulsion were KPNC 77%, KPSC 87%, KPWA 68%, and RI 37%. Across all research sites, breastfeeding status at the time of IUD insertion was determined for 94% of those sampled. CONCLUSIONS: Algorithms with a high PPV for uterine perforation and IUD expulsion were developed at 3 of the 4 research sites. Breastfeeding status at the time of IUD insertion could be determined at all research sites. Our findings suggest that a study to evaluate the associations of breastfeeding and postpartum IUD insertions with risk of uterine perforation and IUD expulsion can be successfully conducted retrospectively; however, automated application of algorithms must be supplemented with chart review for some outcomes at one research site due to low PPV.

RE: "An Estimation of the Risk of Pseudotumor Cerebri Among Users of the Levonorgestrel Intrauterine Device".

The current letter to the editor describes some of the limitations of Valenzuela et al.'s study on the association between levonorgestrel-releasing intrauterine system use and pseudotumor cerebri/idiopathic intracranial hypertension and further reinforces the authors' interpretations of the findings.