Levonorgestrel

INDICATIONS AND USAGE LILETTA is a progestin-containing intrauterine system indicated for: Prevention of pregnancy for up to 8 years ( 1.1 ) Treatment of heavy menstrual bleeding for up to 5 years in patients who choose intrauterine contraception as their method of contraception ( 1.2 ) 1.1 Contraception LILETTA is indicated for prevention of pregnancy for up to 8 years. 1.2 Heavy Menstrual Bleeding LILETTA is indicated for the treatment of heavy menstrual bleeding for up to 5 years in patients who choose to use intrauterine contraception as their method of contraception; replace after the end of the fifth year if continued treatment of heavy menstrual bleeding is needed.

DOSAGE AND ADMINISTRATION • Release rate of levonorgestrel (LNG) is 17.5 mcg/day after 24 days and declines to 7.4 mcg/day after 5 years; Kyleena must be removed or replaced after 5 years. ( 2.1 ) • To be inserted by a trained healthcare provider using strict aseptic technique. Follow insertion instructions exactly as described. ( 2.2 ) • Patient should be re-examined and evaluated 4 to 6 weeks after insertion; then yearly or more often if clinically indicated. ( 2.3 ) 2.1 Dosing Over Time Kyleena contains 19.5 mg of levonorgestrel (LNG) released in vivo at a rate of approximately 17.5 mcg/day after 24 days. This rate decreases progressively to 9.8 mcg/day after 1 year and to 7.4 mcg/day after 5 years. The average in vivo release rate of LNG is approximately 12.6 mcg/day over the first year and 9.0 mcg/day over a period of 5 years . [See Clinical Pharmacology ( 12.3 ).] Kyleena must be removed by the end of the fifth year and can be replaced at the time of removal with a new Kyleena if continued contraceptive protection is desired. Kyleena can be physically distinguished from other intrauterine systems (IUSs) by the combination of the visibility of the silver ring on ultrasound and the blue color of the removal threads. Kyleena is supplied in a sterile package within an inserter that enables single-handed loading (see Figure 1). Do not open the package until required for insertion [see Description ( 11.2 )] . Do not use if the seal of the sterile package is broken or appears compromised. Use strict aseptic techniques throughout the insertion procedure [see Warnings and Precautions ( 5.3 )] . Kyleena and Inserter 2.2. Insertion Instructions • Obtain a complete medical and social history to determine conditions that might influence the selection of a levonorgestrel-releasing intrauterine system (LNG IUS) for contraception . If indicated, perform a physical examination and appropriate tests for any forms of genital or other sexually transmitted infections. [See Contraindications ( 4 ) and Warnings and Precautions ( 5.10 ).] Because irregular bleeding/spotting is common during the first months of Kyleena use, exclude endometrial pathology (polyps or cancer) prior to the insertion of Kyleena in women with persistent or uncharacteristic bleeding [see Warnings and Precautions ( 5.8 )] . • Follow the insertion instructions exactly as described to ensure proper placement and avoid premature release of Kyleena from the inserter. Once released, Kyleena cannot be re-loaded . • Check expiration date of Kyleena prior to initiating insertion. • Kyleena should be inserted by a trained healthcare provider. Healthcare providers should become thoroughly familiar with the insertion instructions before attempting insertion of Kyleena. • Insertion may be associated with some pain and/or bleeding or vasovagal reactions (for example, syncope, bradycardia), or with seizure, especially in patients with a predisposition to these conditions. Consider administering analgesics prior to insertion. Timing of Insertion Table 1: When to Insert Kyleena Starting Kyleena in women not currently using hormonal or intrauterine contraception • Insert Kyleena any time there is reasonable certainty that the woman is not pregnant. Consider the possibility of ovulation and conception prior to initiation of this product [see Contraindications ( 4 )]. • If Kyleena is inserted during the first seven days of the menstrual cycle or immediately after a first trimester abortion, back-up contraception is not needed. • If Kyleena is not inserted during the first seven days of the menstrual cycle, a barrier method of contraception should be used, or the patient should abstain from vaginal intercourse for seven days to prevent pregnancy. Switching to Kyleena from an oral, transdermal or vaginal hormonal contraceptive • Insert Kyleena at any time, including during the hormone-free interval of the previous method. • If inserted during active use of the previous method, continue that method for 7 days after Kyleena insertion or until the end of the current treatment cycle. • If the woman was using continuous hormonal contraception, discontinue that method seven days after Kyleena insertion. Switching to Kyleena from an injectable progestin contraceptive • Insert Kyleena at any time; a non-hormonal back-up birth control (such as condoms or spermicide) should also be used for 7 days if Kyleena is inserted more than 3 months (13 weeks) after the last injection. Switching to Kyleena from a contraceptive implant or another IUS • Insert Kyleena on the same day the implant or IUS is removed. • Insert Kyleena at any time during the menstrual cycle. Inserting Kyleena after first trimester abortion or miscarriage • Insert Kyleena immediately after a first-trimester abortion or miscarriage, unless it is a septic abortion [see Contraindications ( 4 )]. Inserting Kyleena after childbirth or second-trimester abortion or miscarriage • Immediate insertion after childbirth or second-trimester abortion or miscarriage • Insert Kyleena after removal of the placenta. Back-up contraception is not needed. [See Contraindications ( 4 ), Warnings and Precautions ( 5.5 , 5.6 ), Adverse Reactions ( 6.2 )]. Interval insertion following complete involution of the uterus • Wait a minimum of 6 weeks or until the uterus is fully involuted before inserting Kyleena [see Warnings and Precautions ( 5.5 , 5.6) , Adverse Reactions ( 6.2 )]. • Insert Kyleena any time there is reasonable certainty the woman is not pregnant. • If Kyleena is not inserted during the first 7 days of the menstrual cycle, a back-up method of contraception should be used, or the woman should abstain from vaginal intercourse for 7 days to prevent pregnancy [see Contraindications ( 4 ), Warnings and Precautions ( 5.2 )]. Tools for Insertion Note: The inserter provided with Kyleena (see Figure 1) and the Insertion Procedure described in this section are not applicable for immediate insertion after childbirth or second-trimester abortion or miscarriage. For immediate insertion, remove Kyleena from the inserter by first loading (see Figure 2) and then releasing (see Figure 7) Kyleena from the inserter, and insert according to accepted practice. Preparation • Gloves • Speculum • Sterile uterine sound • Sterile tenaculum • Antiseptic solution, applicator Procedure • Sterile gloves • Kyleena with inserter in sealed package • Instruments and anesthesia for paracervical block, if anticipated • Consider having an unopened back-up Kyleena available • Sterile, sharp curved scissors Preparation for insertion • Exclude pregnancy and confirm that there are no other contraindications to the use of Kyleena. • With the patient comfortably in lithotomy position, do a bimanual exam to establish the size, shape and position of the uterus. • Gently insert a speculum to visualize the cervix. • Thoroughly cleanse the cervix and vagina with a suitable antiseptic solution. • Prepare to sound the uterine cavity. Grasp the upper lip of the cervix with a tenaculum forceps and gently apply traction to stabilize and align the cervical canal with the uterine cavity. Perform a paracervical block if needed. If the uterus is retroverted, it may be more appropriate to grasp the lower lip of the cervix. The tenaculum should remain in position and gentle traction on the cervix should be maintained throughout the insertion procedure. • Gently insert a uterine sound to check the patency of the cervix, measure the depth of the uterine cavity in centimeters, confirm cavity direction, and detect the presence of any uterine anomaly. If you encounter difficulty or cervical stenosis, use dilatation, and not force, to overcome resistance. If cervical dilatation is required, consider using a paracervical block. Insertion Procedure Proceed with insertion only after completing the above steps and ascertaining that the patient is appropriate for Kyleena. Ensure use of aseptic technique throughout the entire procedure . S

WARNINGS AND PRECAUTIONS • Remove Kyleena if pregnancy occurs with Kyleena in place. If pregnancy occurs, there is increased risk of ectopic pregnancy including loss of fertility, pregnancy loss, septic abortion (including septicemia, shock and death), and premature labor and delivery. ( 5.1 , 5.2 ) • Group A streptococcal infection has been reported following insertion of LNG IUS; strict aseptic technique is essential during insertion. ( 5.3 ) • Before using Kyleena, consider the risks of PID. ( 5.4 ) • Uterine perforation may occur and may reduce contraceptive effectiveness or require surgery. Risk is increased if inserted in lactating women and may be increased if inserted in women with fixed retroverted uteri and postpartum. ( 5.5 ) • Partial or complete expulsion may occur, which can be unnoticed, leading to loss of contraceptive efficacy. ( 5.6 ) • Evaluate persistent enlarged ovarian follicles or ovarian cysts. ( 5.7 ) • Bleeding patterns become altered, may remain irregular and amenorrhea may ensue. ( 5.8 ) • Kyleena can be safely scanned with MRI only under certain conditions. ( 5.11 ) 5.1 Risk of Ectopic Pregnancy Evaluate women for ectopic pregnancy if they become pregnant with Kyleena in place because the likelihood of a pregnancy being ectopic is increased with Kyleena. Approximately one-half of pregnancies that occur with Kyleena in place are likely to be ectopic. Also consider the possibility of ectopic pregnancy in the case of lower abdominal pain, especially in association with missed menses or if an amenorrheic woman starts bleeding. The incidence of ectopic pregnancy in clinical trials with Kyleena, which excluded women with a history of ectopic pregnancy, was approximately 0.2% per year. The risk of ectopic pregnancy in women who have a history of ectopic pregnancy and use Kyleena is unknown. Women with a previous history of ectopic pregnancy, tubal surgery or pelvic infection carry a higher risk of ectopic pregnancy. Ectopic pregnancy may result in loss of fertility. 5.2 Risks with Intrauterine Pregnancy If pregnancy occurs while using Kyleena, remove Kyleena because leaving it in place may increase the risk of spontaneous abortion and preterm labor. Removal of Kyleena or probing of the uterus may also result in spontaneous abortion. In the event of an intrauterine pregnancy with Kyleena, consider the following: Septic abortion In patients becoming pregnant with an IUS in place, septic abortion—with septicemia, septic shock, and death—may occur. Continuation of pregnancy If a woman becomes pregnant with Kyleena in place and if Kyleena cannot be removed or the woman chooses not to have it removed, warn her that failure to remove Kyleena increases the risk of miscarriage, sepsis, premature labor and premature delivery. Advise her of isolated reports of virilization of the female fetus following local exposure to LNG during pregnancy with an LNG IUS in place [see Use in Specific Populations ( 8.1 )] . Follow her pregnancy closely and advise her to report immediately any symptom that suggests complications of the pregnancy. 5.3 Sepsis Severe infection or sepsis, including Group A streptococcal sepsis (GAS), have been reported following insertion of a LNG-releasing IUS. In some cases, severe pain occurred within hours of insertion followed by sepsis within days. Because death from GAS is more likely if treatment is delayed, it is important to be aware of these rare but serious infections. Aseptic technique during insertion of Kyleena is essential in order to minimize serious infections such as GAS. 5.4 Pelvic Infection Promptly examine users with complaints of lower abdominal or pelvic pain, odorous discharge, unexplained bleeding, fever, genital lesions or sores. Remove Kyleena in cases of recurrent endometritis or pelvic inflammatory disease, or if an acute pelvic infection is severe or does not respond to treatment. Pelvic Inflammatory Disease (PID) Kyleena is contraindicated in the presence of known or suspected PID or in women with a history of PID unless there has been a subsequent intrauterine pregnancy [see Contraindications ( 4 )] . IUDs have been associated with an increased risk of PID, most likely due to organisms being introduced into the uterus during insertion. In clinical trials, PID was observed in 0.5% of women overall and occurred more frequently within the first year and most often within the first month after insertion of Kyleena. Women at increased risk for PID PID is often associated with a sexually transmitted infection (STI), and Kyleena does not protect against STI. The risk of PID is greater for women who have multiple sexual partners, and also for women whose sexual partner(s) have multiple sexual partners. Women who have had PID are at increased risk for a recurrence or re-infection. In particular, ascertain whether the woman is at increased risk of infection (for example, leukemia, acquired immune deficiency syndrome [AIDS], intravenous drug abuse). Subclinical PID PID may be asymptomatic but still result in tubal damage and its sequelae. Treatment of PID Following a diagnosis of PID, or suspected PID, bacteriologic specimens should be obtained, and antibiotic therapy should be initiated promptly. Removal of Kyleena after initiation of antibiotic therapy is usually appropriate. 1 Actinomycosis Actinomycosis has been associated with IUDs. Remove Kyleena from symptomatic women and treat with antibiotics. The significance of actinomyces-like organisms on Pap smear in an asymptomatic IUD user is unknown, and so this finding alone does not always require Kyleena removal and treatment. When possible, confirm a Pap smear diagnosis with cultures. 5.5 Perforation Perforation (total or partial, including penetration/embedment of Kyleena in the uterine wall or cervix) may occur most often during insertion, although the perforation may not be detected until sometime later. The incidence of perforation during clinical trials was < 0.1%. The risk of uterine perforation is increased in women who have recently given birth, and in women who are breastfeeding at the time of insertion. In a large postmarketing safety study conducted in the US, the risk of uterine perforation was highest when insertion occurred within ≤ 6 weeks postpartum, and also higher with breastfeeding at the time of insertion [see Adverse Reactions ( 6.2 )]. The risk of perforation may be increased if Kyleena is inserted when the uterus is fixed, retroverted or not completely involuted. If perforation occurs, locate and remove Kyleena. Surgery may be required. Delayed detection or removal of Kyleena in case of perforation may result in migration outside the uterine cavity, adhesions, peritonitis, intestinal perforations, intestinal obstruction, abscesses and erosion of adjacent viscera. In addition, perforation may reduce contraceptive efficacy and result in pregnancy. 5.6 Expulsion Partial or complete expulsion of Kyleena may occur resulting in the loss of efficacy. Expulsion may be associated with symptoms of bleeding or pain, or it may be asymptomatic and go unnoticed. Kyleena typically decreases menstrual bleeding over time; therefore, an increase of menstrual bleeding may be indicative of an expulsion. Consider further diagnostic imaging, such as x-ray, if expulsion is suspected based on ultrasound [see Warnings and Precautions ( 5.10 )]. In clinical trials, a 5-year expulsion rate of 3.5% (59 out of 1,690 subjects) was reported. The risk of expulsion is increased with insertions immediately after delivery and appears to be increased with insertion after second-trimester abortion based on limited data. In a large postmarketing safety study conducted in the US, the risk of expulsion was lower with breastfeeding status [see Adverse Reactions ( 6.2 )]. Remove a partially expelled Kyleena. If expulsion has occurred, a new Kyleena can be inserted any time the provider can be reasonably certain the woman is not pregnant. 5.7 Ovarian Cysts Because the

CONTRAINDICATIONS LILETTA is contraindicated when one or more of the following conditions exist: Pregnancy [see Use in Specific Populations ( 8.1 ) ] For use as post-coital contraception (emergency contraception) Congenital or acquired uterine anomaly, including leiomyomas, that distorts the uterine cavity and would be incompatible with correct IUS placement [see Warnings and Precautions ( 5.10 )] Acute pelvic inflammatory disease (PID) [see Warnings and Precautions ( 5.4 )] Postpartum endometritis or infected abortion in the past 3 months [see Warnings and Precautions ( 5.2 , 5.4 )] Known or suspected uterine or cervical malignancy Known or suspected breast cancer or other hormone-sensitive cancer, now or in the past [see Warnings and Precautions ( 5.9 )] Uterine bleeding of unknown etiology [see Warnings and Precautions ( 5.10 )] Untreated acute cervicitis or vaginitis, including bacterial vaginosis, known chlamydial or gonococcal cervical infection, or other lower genital tract infections until infection is controlled [see Warnings and Precautions ( 5.4 )] Acute liver disease or liver tumor (benign or malignant) Conditions associated with increased susceptibility to pelvic infections [see Warnings and Precautions ( 5.4 )] A previously inserted IUS that has not been removed A history of hypersensitivity reaction to any component of LILETTA. Reactions may include rash, urticaria, and angioedema [see Adverse Reactions ( 6.2 )] . Pregnancy ( 4 ) Use for post-coital contraception (emergency contraception) ( 4 ) Congenital or acquired uterine anomaly that distorts the uterine cavity and would be incompatible with correct IUS placement ( 4 ) Acute pelvic inflammatory disease (PID) ( 4 ) Postpartum endometritis or infected abortion in the past 3 months ( 4 ) Known or suspected uterine or cervical malignancy ( 4 ) Known or suspected breast cancer or other hormone-sensitive cancer ( 4 ) Uterine bleeding of unknown etiology ( 4 ) Untreated acute cervicitis or vaginitis or other lower genital tract infections ( 4 ) Acute liver disease or liver tumor (benign or malignant) ( 4 ) Increased susceptibility to pelvic infections ( 4 ) A previously inserted IUS that has not been removed ( 4 ) Hypersensitivity to any component of LILETTA ( 4 )

DRUG INTERACTIONS No drug-drug interaction studies have been conducted with Kyleena. Drugs or herbal products that induce or inhibit LNG metabolizing enzymes, including CYP3A4, may decrease or increase, respectively, the serum concentrations of LNG during the use of Kyleena. However, the contraceptive effect of Kyleena is mediated via the direct release of LNG into the uterine cavity and is unlikely to be affected by drug interactions via enzyme induction or inhibition.

ADVERSE REACTIONS The following serious or otherwise important adverse reactions are discussed elsewhere in the labeling: • Ectopic Pregnancy [see Warnings and Precautions ( 5.1 )] • Intrauterine Pregnancy [see Warnings and Precautions ( 5.2 )] • Group A Streptococcal Sepsis (GAS) [see Warnings and Precautions ( 5.3 )] • Pelvic Inflammatory Disease [see Warnings and Precautions ( 5.4 )] • Perforation [see Warnings and Precautions ( 5.5 )] • Expulsion [see Warnings and Precautions ( 5.6 ] • Ovarian Cysts [see Warnings and Precautions ( 5.7 )] • Bleeding Pattern Alterations [see Warnings and Precautions ( 5.8 )] The most common adverse reactions reported (≥ 5% users) were vulvovaginitis, ovarian cysts, abdominal pain/pelvic pain, headache/migraine, acne/seborrhea, dysmenorrhea/uterine spasm, breast pain/breast discomfort, and increased bleeding. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Bayer HealthCare Pharmaceuticals Inc. at 1-888-842-2937 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The data described below reflect exposure of 1,697 healthy 18 to 41-year-old women (mean age 27.8 ± 5.2 years) to Kyleena. These data come from two multi-center contraceptive trials: A phase 2 study with a 3-year duration was conducted in Europe enrolling generally healthy, 21 to 41-year old women; 217 subjects were exposed to Kyleena for one year and 174 completed three years. The data in this trial cover approximately 8,000 cycles of exposure. A phase 3 study with a 3-year duration and an optional extension of Kyleena use up to 5 years was conducted in the United States (US), Canada, Europe, and Latin America. The population was generally healthy, 18 to 35-year old women. A total of 1,208 subjects were exposed to Kyleena for at least one year; 707 women entered the optional extension phase after 3 years and 550 completed five years. The data in this trial cover approximately 60,000 cycles. In total for both studies, 1,425 subjects were exposed for at least 1 year, and 550 subjects completed 5 years of use. Of the total of 1,697 subjects exposed to Kyleena, 563 were from the US and 1,134 were from Europe, Canada and Latin America; 623 (37%) were nulliparous (mean age 24.6 ± 4.5 years) and 1,074 (63%) were parous (mean age 29.7 ± 4.7 years). Most women who received Kyleena were Caucasian (83%) or Black/African American (4.4%); 9.4% of women were of Hispanic ethnicity. The clinical trials had no upper or lower weight or body mass index (BMI) limit. Mean BMI of Kyleena subjects was 25.2 kg/m2 (range 15.2 – 57.6 kg/m2); 16% had a BMI ≥ 30 kg/m2, and 2.0% had a BMI ≥ 40 kg/m2. The frequencies of reported adverse drug reactions represent crude incidences. The most common adverse reactions (occurring in ≥ 5% users) were vulvovaginitis (24%), ovarian cyst (22%), abdominal pain/pelvic pain (21%), headache/migraine (15%), acne/seborrhea (15%), dysmenorrhea/uterine spasm (10%), breast pain/breast discomfort (10%), and increased bleeding (8%). In the combined studies, 22% discontinued prematurely due to an adverse reaction. The most common adverse reactions (>1%) leading to discontinuation were increased bleeding (4.5%), abdominal pain/pelvic pain (4.2%), device expulsion (3.1%), acne/seborrhea (2.3%), and dysmenorrhea/uterine spasm (1.3%). Common adverse reactions (occurring in ≥1% users) are summarized in Table 4 (presented as crude incidences). Table 4: Adverse reactions that occurred in at least 1% of Kyleena users in clinical trials by System Organ Class (SOC) System Organ Class Adverse Reaction Incidence (%) (N=1,697) Reproductive System and Breast Disorders Vulvovaginitis 24.3 Ovarian cyst a 22.2 Dysmenorrhea/uterine spasm 8.0/2.4 Increased bleeding b 7.9 Breast pain/discomfort 7.1/3.5 Genital discharge 4.5 Device expulsion (complete and partial) 3.5 Upper genital tract infection 1.5 Gastrointestinal Disorders Abdominal pain/pelvic pain 13.3/8.2 Nausea 4.7 Skin and Subcutaneous Tissue Disorders Acne/Seborrhea 14.1/1.8 Alopecia 1.0 Nervous System Disorders Headache/Migraine 12.9/3.3 Psychiatric Disorders Depression/ Depressed mood 4.4/0.2 a Ovarian cysts were reported as adverse events if they were abnormal, non-functional cysts and/or had a diameter >3 cm on ultrasound examination b Not all bleeding alterations were captured as adverse reactions [see Warnings and Precautions ( 5.8 )] . In the clinical trials, serious adverse reactions occurring in more than a single subject included: ectopic pregnancy/ruptured ectopic pregnancy (10 subjects); pelvic inflammatory disease (6 subjects); missed abortion/incomplete spontaneous abortion/spontaneous abortion (4 subjects); ovarian cyst (3 subjects); abdominal pain (4 subjects); depression/affective disorder (4 subjects); and uterine perforation/embedded device (myometrial perforation) (3 subjects). 6.2 Postmarketing Experience Adverse Reactions from Postmarketing Spontaneous Reports The following adverse reactions have been identified during post-approval use of LNG-releasing IUSs. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. • Arterial thrombotic and venous thromboembolic events, including cases of pulmonary embolism, deep vein thrombosis and stroke • Device breakage • Hypersensitivity (including rash, urticaria, and angioedema) • Increased blood pressure Reported Adverse Reactions from Postmarketing Studies Assessment of Perforation and Expulsion of Intrauterine Devices (APEX IUD) Study APEX IUD was a large US retrospective cohort study to assess the impact of breastfeeding and timing of postpartum IUD insertion on uterine perforation and IUD expulsion. The analyses included a total of 326,658 insertions, 30% (97,824 insertions) of which were performed in women with a delivery in the previous 12 months. For insertions performed in women who had delivered ≤ 52 weeks before IUD insertion, the majority of postpartum insertions, 57.3% (56,047 insertions) occurred between 6 and 14 weeks postpartum. Breastfeeding data were available in 94,817 insertions performed in women 52 weeks or less after delivery. The study results indicated that the risk of uterine perforation was highest in women with IUD insertion ≤ 6 weeks postpartum. Immediate postpartum insertion (0–3 days) findings are limited due to the relatively small number of insertions occurring within this time interval. Women who were breastfeeding at the time of insertion were at 33% higher risk of perforation (adjusted hazard ratio [HR]=1.33, 95% confidence interval [CI]: 1.07–1.64) compared to women who were not breastfeeding at the time of insertion. Progressively lower risk of uterine perforation was observed in postpartum time windows beyond 6 weeks, in both breastfeeding and not breastfeeding women. Table 5 presents the uterine perforation rates for LNG IUS stratified by breastfeeding status and postpartum interval. Table 5: Uterine Perforation 1 rates for LNG IUS, by Breastfeeding Status and Postpartum Interval Breastfeeding at time of insertion Not breastfeeding at time of insertion Postpartum interval at time of insertion Number of events/ insertions Uterine perforation rate per 1,000 insertions Number of events/ insertions Uterine perforation rate per 1,000 insertions 0 to 3 days 8/1,896 4.22 0/277 0.00 4 days to ≤ 6 weeks 120/10,735 11.18 28/2,377 11.78 > 6 to ≤ 14 weeks 268/29,677 9.03 80/12,011 6.66 > 14 to ≤ 52 weeks 43/6,139 7.00 22/9,089 2.42 > 52 weeks or no delivery no data available 243/184,733 1.32 1 Uterine perforation includes both complete and partial perforation Risk of expulsion was var

Mechanism of Action The local mechanism by which continuously released LNG provides contraception has not been conclusively demonstrated. Studies of LNG-releasing IUSs suggest several mechanisms for pregnancy prevention: prevention of fertilization due to the thickening of the cervical mucus, which inhibits sperm passage through the cervix, and inhibition of sperm mobility and function (capacitation), and alteration of the endometrium.