Health benefits of combined oral contraceptives - a narrative review.

PURPOSE: This review presents an update of the non-contraceptive health benefits of the combined oral contraceptive pill. METHODS: We conducted a literature search for (review) articles that discussed the health benefits of combined oral contraceptives (COCs), in the period from 1980 to 2023. RESULTS: We identified 21 subjective and/or objective health benefits of COCs related to (i) the reproductive tract, (ii) non-gynaecological benign disorders and (iii) malignancies. Reproductive tract benefits are related to menstrual bleeding(including anaemia and toxic shock syndrome), dysmenorrhoea, migraine, premenstrual syndrome (PMS), ovarian cysts, Polycystic Ovary Syndrome (PCOS), androgen related symptoms, ectopic pregnancy, hypoestrogenism, endometriosis and adenomyosis, uterine fibroids and pelvic inflammatory disease (PID). Non-gynaecological benefits are related to benign breast disease, osteoporosis, rheumatoid arthritis, multiple sclerosis, asthma and porphyria. Health benefits of COCs related to cancer are lower risks of endometrial cancer, ovarian cancer and colorectal cancer. CONCLUSIONS: The use of combined oral contraceptives is accompanied with a range of health benefits, to be balanced against its side-effects and risks. Several health benefits of COCs are a reason for non-contraceptive COC prescription.

Medical abortion in the second trimester - an update.

The safety and efficacy of medical abortion in the second trimester is provider independent and may therefore offer advantages over surgical second trimester abortion in certain settings. Due to bleeding risk, medical abortions in the second trimester are still mostly performed in a clinic or hospital setting. The most effective regimen for abortion includes pretreatment with oral mifepristone and following doses of misoprostol. An alternative is misoprostol only which should only be used when mifepristone is not available. The optimal dosing of prostaglandin to achieve the highest efficacy with the lowest proportion of complications remains to be established. Complications are rare and serious adverse events uncommon but may include uterine rupture especially in women with a previous cesarean delivery or uterine surgery. Women having second trimester medical abortion are a diverse group with different indications for the abortion. All women should be offered pain relief and respectful care. Staff involved in second trimester medical abortion often find their work challenging. At the same time, staff indicate pride and a conviction of contributing to the 'greater good' for women and society. Staff involved in second trimester abortion should be offered guidance and support through the employer. Post abortion contraception should be offered to all women having second trimester medical abortions, including those who have the abortion due to fetal malformation. All methods of contraception can be started immediately after a second trimester medical abortion except for cycle based methods and diaphragms.

Molecular subclass of uterine fibroids predicts tumor shrinkage in response to ulipristal acetate.

Precision medicine carries great potential for management of all tumor types. The aim of this retrospective study was to investigate if the two most common genetically distinct uterine fibroid subclasses, driven by aberrations in MED12 and HMGA2 genes, respectively, influence response to treatment with the progesterone receptor modulator ulipristal acetate. Changes in diameter and mutation status were derived for 101 uterine fibroids surgically removed after ulipristal acetate treatment. A significant difference in treatment response between the two major subclasses was detected. MED12 mutant fibroids had 4.4 times higher odds of shrinking in response to ulipristal acetate treatment as compared to HMGA2 driven fibroids (95% confidence interval 1.37-13.9; P = 0.013), and in a multivariate analysis molecular subclassification was an independent predictive factor. Compatible with this finding, gene expression and DNA methylation analyses revealed subclass specific differences in progesterone receptor signaling. The work provides a proof-of-principle that uterine fibroid treatment response is influenced by molecular subclass and that the genetic subclasses should be taken into account when evaluating current and future uterine fibroid therapies.

Long term follow-up of uterine fibroids treated with microwave ablation: an up to 3-year observational study of volume, regrowth, and symptoms.

OBJECTIVE: To study long-term effects in patients treated with microwave ablation (MWA) for symptomatic uterine fibroids and investigate fibroid characteristics predictive of successful treatment. METHOD: Women who received MWA treatment for uterine fibroids in a previous study were included. A total of 16 patients underwent contrast enhanced MRI before treatment, postoperatively at 6 months and at long-term follow-up, to assess volumes of treated fibroids (n = 42). Long-term MRI was performed between 16 and 36 months after treatment [median 22 months, interquartile range (IQR) 18.5-27]. Validated questionnaires for evaluation of uterine fibroid symptoms and menstrual bleeding (UFS-QoL and PBAC) were used to assess long-term effects on symptoms. The degree of shrinkage was correlated to vascularization and T2 signal intensity (SI) at preoperative MRI and location of fibroids according to the FIGO classification, using the Mann-Whitney U test. RESULTS: Most patients (82%) reported improvement up to 3 years after treatment. Out of 42 treated fibroids, 35 (83%) continued to shrink over time with median relative volume reduction of 77% (IQR 39-95). For eight fibroids (19%) which showed low vascularization on the pretreatment MRI, there was less shrinkage compared to well-vascularized fibroids (p = 0.01). Most fibroids (79%) showed iso- to hyperintense T2 signal on preoperative MRI and showed a higher grade of shrinkage than hypointense fibroids (p = 0.02). CONCLUSION: After microwave treatment improvement is maintained for most patients up to 36 months and most fibroids showed continuous shrinkage. Preoperative vascularization, high T2 SI and submucosal location predicted continuous volume reduction. However, to confirm this, larger studies are needed.

Ultrasound guided microwave ablation compared to uterine artery embolization treatment for uterine fibroids - a randomized controlled trial.

OBJECTIVE: To evaluate the efficacy, feasibility and acceptability of microwave ablation (MWA) compared to uterine artery embolization (UAE) as treatment for uterine fibroids. METHOD: A randomized controlled superiority trial, including premenopausal women 30-55 years, with symptomatic uterine fibroids without any single fibroid exceeding mean diameter of eight centimeters. Patients were randomized to receive microwave ablation, performed abdominally or vaginally, or to uterine artery embolization. The primary outcome was volume difference of the three largest fibroids at 6 months post treatment evaluated by magnetic resonance imaging (MRI) by a blinded radiologist analyzed by Mann-Whitney U-test. Secondary outcomes included symptom severity score (SSS), health related quality of life (HR-QoL), amount of menstrual bleeding, postoperative pain, length of hospitalization, need for additional treatment, adverse events and if patients would recommend the treatment to a friend. RESULTS: Patients were recruited from 30 January 2017 to 12 September 2019, with a total of 17 patients treated in each group from May 2017 to December 2019. Superiority of MWA could not be established. The volume reduction was 41.8% (Interquartile range, IQR, 14-63) in the MWA group compared to 62.2% (IQR 34.9-80.1) in the UAE group (p = 0.29). Effects on symptoms, HR-QoL and acceptability did not differ between groups. Days of hospitalization and sick leave were significantly fewer in the MWA group (p < 0.001 and p = 0.001). CONCLUSIONS: Although superiority of MWA could not be established, it is a promising technique for treating uterine fibroids. It was well tolerated and associated with lower use of health care resources. Trial registration: NCT02942537, www.clincialtrials.gov.

Ulipristal Acetate for Treatment of Premenstrual Dysphoric Disorder: A Proof-of-Concept Randomized Controlled Trial.

OBJECTIVE: Premenstrual dysphoric disorder (PMDD) is a common mood disorder, characterized by distressing affective, behavioral, and somatic symptoms in the late luteal phase of the menstrual cycle. The authors investigated continuous treatment with a selective progesterone receptor modulator, ulipristal acetate (UPA), as a potential treatment for PMDD. METHODS: The authors conducted an investigator-initiated, multicenter, double-blind, randomized, parallel-group clinical trial in which women with PMDD (N=95) were treated with either 5 mg/day of UPA or placebo during three 28-day treatment cycles. The primary outcome was the change in premenstrual total score on the Daily Record of Severity of Problems (DRSP) from baseline to end of treatment. DRSP scores were captured by daily ratings using a smartphone application and were analyzed with linear mixed models for repeated measures. RESULTS: The mean improvement in DRSP score after 3 months was 41% (SD=18) in the UPA group, compared with 22% (SD=27) in the placebo group (mean difference -18%; 95% CI=-29, -8). Treatment effects were also noted for the DRSP depressive symptom subscale (42% [SD=22] compared with 22% [SD=32]) and the DRSP anger/irritability subscale (47% [SD=21] compared with 23% [SD=35]), but not for the DRSP physical symptom subscale. Remission based on DRSP score was attained by 20 women in the UPA group (50.0%) and eight women in the placebo group (21.1%) (a statistically significant difference). CONCLUSIONS: If these results are replicated, UPA could be a useful treatment for PMDD, particularly for the psychological symptoms associated with the disorder.

Pharmacokinetics of Oral Levonorgestrel in Women After Roux-en-Y Gastric Bypass Surgery and in BMI-Matched Controls.

BACKGROUND: Women are advised to primarily use non-oral contraceptive alternatives after Roux-en-Y gastric bypass since it is not known if the surgery affects the pharmacokinetics of oral contraceptives. METHODS: This is a multi-center, open label, phase 2 pharmacokinetic study performed at the University Hospital of Linköping and the Clinical Trials Center, Department of Obstetrics and Gynecology, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden. Fifteen women aged 18-40 years who had previously undergone Roux-en-Y gastric bypass surgery and reached a BMI < 30 were included. Fifteen BMI-matched women with no previous history of Roux-en-Y gastric bypass surgery served as a control group. After administration of a single dose of a combined oral contraceptive containing 0.03 mg ethinylestradiol/0.15 mg levonorgestrel, serum levonorgestrel concentrations were determined during a 24-h period using ultra performance liquid chromatography/tandem mass spectrometry. The area under the plasma concentration time curve of levonorgestrel (AUC0-24h) was the main outcome measure. RESULTS: There were no significant differences in the studied pharmacokinetic parameters, AUC0-24h, total AUC, peak serum concentration (Cmax), time to peak serum concentrations (Tmax), apparent oral clearances of levonorgestrel (CLoral), or terminal half-lives (t½) between the groups. CONCLUSION: This is to our knowledge the first study to evaluate the pharmacokinetics of oral levonorgestrel in women with a BMI < 30 at least 1 year after RYGB compared with a BMI-matched group of women. We could not find any significant pharmacokinetic differences between the groups, suggesting that oral levonorgestrel may be used in non-obese women after Roux-en-Y gastric bypass once a stable body weight has been reached. CLINICAL TRIAL NUMBER: EudraCT 2014-004677-17.

Risk of abortion within 1-2 years after childbirth in relation to contraceptive choice: a retrospective cohort study.

Objectives: The primary objective of the study was to investigate whether the choice of long-acting reversible contraception (LARC) was associated with the risk of abortion over a period of 24 months postpartum. The secondary objective was to analyse whether other significant factors were affecting the risk of abortion during this period.Methods: In this retrospective cohort study, we analysed 11,066 women who had delivered in three Swedish cities during 2013 and 2014. Demographic and medical variables were obtained from medical records. Attendance at the postpartum visit, choice of postpartum contraception and history of abortion was noted. Logistic regression analysis was performed to assess factors associated with the risk of abortion. The main outcome measure was the proportion of women with abortion up to 24 months postpartum.Results: Data from 11,066 women were included in the final analysis. Within 12-24 months after delivery 2.5% of women had an abortion. The choice of LARC after childbirth reduced the risk of subsequent abortion (odds ratio 0.74; 95% confidence interval [CI] 0.60, 0.91; p =  .005). Smoking, age <25 years and have had a previous abortion significantly increased the risk of abortion during follow-up, whereas exclusive breastfeeding decreased the risk.Conclusions: Increasing the proportion of women who choose LARC postpartum could decrease the risk of abortion for up to 2 years after childbirth.

Efficacy of mifepristone and misoprostol for medical treatment of missed miscarriage in clinical practice-A cohort study.

INTRODUCTION: It has been estimated that one out of every four women experience first-trimester miscarriage. Missed miscarriage is a common form of early miscarriage where the products of conception are not expelled from the uterus. It is diagnosed by ultrasound. The primary objective of this study was to evaluate the success rate of a combination treatment with mifepristone and misoprostol for missed miscarriage in clinical practice. The secondary objective was to identify significant factors influencing the rate of success. MATERIAL AND METHODS: A cohort of 941 consecutive women with an ICD-10 diagnosis of missed miscarriage who received treatment with 800 µg vaginal misoprostol and 2 repeat doses of 400 µg oral misoprostol after mifepristone pretreatment between 1 January 2012 and 31 December 2014 was analyzed. Women with a uterine size smaller than 12 weeks who were planned for medical treatment were included in the study. The exclusion criteria were primary surgical management or planned follow up outside the Stockholm County Council area. RESULTS: The success rate of medical treatment, defined as no need for surgical treatment, was 85.5% (805/941) in women with a uterine size of less than 12 weeks. However, for women with uterine size below 9 weeks the success rate was 88.9% (586/659). Indeed, uterine size of 9 gestational weeks or larger at time of treatment was identified as the only significant risk factor for surgical intervention. CONCLUSIONS: The medical regimen for missed miscarriage offered in this study appears to be safe and with high rates of success. Conclusions about which women to exclude from medical treatment could not be made. Medical treatment may therefore benefit all women with missed miscarriage who wish to avoid primary surgery.

Association of Attention-Deficit/Hyperactivity Disorder With Teenage Birth Among Women and Girls in Sweden.

Importance: Attention-deficit/hyperactivity disorder (ADHD) is associated with a plethora of adverse health outcomes throughout life. While Swedish specialized youth clinics have carefully and successfully targeted risk of unplanned pregnancies in adolescents, important risk groups, such as women and girls with ADHD, might not be identified or appropriately assisted by these interventions. Objectives: To determine whether women and girls with ADHD are associated with increased risk of teenage birth compared with their unaffected peers and to examine the association of ADHD with risk factors for adverse obstetric and perinatal outcomes, such as smoking, underweight or overweight, and substance use disorder. Design, Setting, and Participants: This nationwide cohort study included data from 6 national longitudinal population-based registries in Sweden. All nulliparous women and girls who gave birth in Sweden between January 1, 2007, and December 31, 2014, were included. Data analyses were conducted from October 7, 2018, to February 8, 2019. Exposures: Women and girls treated with stimulant or nonstimulant medication for ADHD (Anatomic Therapeutic Chemical classification code N06BA) in the Swedish Prescribed Drug Register between July 1, 2005, and December 31, 2014. Main Outcomes and Measures: Maternal age at birth. Secondary outcome measures were body mass index, smoking habits, and psychiatric comorbidities. Results: Among 384 103 nulliparous women and girls aged 12 to 50 years who gave birth between 2007 and 2014 included in the study, 6410 (1.7%) (mean [SD] age, 25.0 [5.5] years) were identified as having ADHD. The remaining 377 693 women and girls without ADHD (mean [SD] age, 28.5 [5.1] years) served as the control group. Teenage deliveries were more common among women and girls with ADHD than among women and girls without ADHD (15.3% vs 2.8%; odds ratio [OR], 6.23 [95% CI, 5.80-6.68]). Compared with women and girls without ADHD, those with ADHD were more likely to present with risk factors for adverse obstetric and perinatal outcomes, including smoking during the third trimester (OR, 6.88 [95% CI, 6.45-7.34]), body mass index less than 18.50 (OR, 1.29 [95% CI, 1.12-1.49]), body mass index more than 40.00 (OR, 2.01 [95% CI, 1.60-2.52]), and alcohol and substance use disorder (OR, 20.25 [95% CI, 18.74-21.88]). Conclusions and Relevance: This study found that women and girls with ADHD were associated with an increased risk of giving birth as teenagers compared with their unaffected peers. The results suggest that standard of care for women and girls with ADHD should include active efforts to prevent teenage pregnancies.

Investigating the loss of work productivity due to symptomatic leiomyoma.

INTRODUCTION: Leiomyoma affects up to 50% of fertile women, leading to morbidity such as bleeding or pain. The effect of symptomatic leiomyoma on the productivity of employed women is understudied. The present study investigates productivity loss in a Swedish setting in women with symptomatic leiomyoma compared to healthy women. MATERIAL AND METHODS: Women seeking care for leiomyoma and heavy menstrual bleeding (HMB) were recruited at nine Swedish sites. Healthy controls with self-perceived mild to normal menstruation were recruited at routine visits. Cases and controls were employed without option to work from home. After recruitment, all women reported the work productivity and activity impairment (WPAI) questionnaire, the pictorial blood assessment chart (PBAC) and pain on the visual analog scale (VAS). RESULTS: Women with symptomatic leiomyoma (n = 88) missed more working time during menses compared to asymptomatic controls (n = 34): 7.6 vs 0.2% p = 0.003. The proportion of impairment while working was also significantly higher in women with symptomatic leiomyoma (43.8 vs 12.1% p<0.001). Moreover, cases reported greater activity impairment outside office hours (43.9 vs 12.1%, p<0.001). Among healthy controls, 69.5% reported symptoms of HMB (PBAC>100). CONCLUSIONS: Symptomatic leiomyoma leads to loss of working hours as well as loss of productivity during working hours, and affects women in other daily activities. Increased awareness of the impact of leiomyomas on women's lives is needed, and timely and appropriate management of the symptomatic leiomyomas could improve work productivity and quality of life.

Transurethral Polyacrylamide Hydrogel Injection Therapy in Women Not Eligible for Midurethral Sling Surgery.

OBJECTIVES: This study aims to determine the effects of transurethral polyacrylamide hydrogel injection in patients considered ineligible for midurethral sling surgery. METHODS: In this prospective observational study, 81 patients received treatment with transurethral polyacrylamide hydrogel injection. Patients were considered ineligible for placement of a midurethral sling based on significant comorbidity (48%), 1 or more previously failed invasive treatments (16%), mixed urinary incontinence (27%), continuous incontinence (5%), or previous pelvic radiation therapy (4%). Longitudinal assessment of subjective treatment outcomes was performed using the validated Urinary Distress Inventory (UDI) and the Pelvic Floor Impact Questionnaire at baseline, 2, and 6 months. To deal with repeated measurements, mixed linear models were used to assess changes in the outcomes over time. RESULTS: There was a significant improvement in the overall UDI score from baseline to month 2 follow-up (FU) (P<0.001). No major differences between the month 2 and 6 FUs were observed. The largest difference in effect was observed for the irritative and stress subscales. Twenty-five patients (33%) requested a second injection at the month 2 FU visit. At month 6 FU, the UDI scores for patients having had only 1 injection were largely unchanged, whereas all UDI domains worsened further for patients having had a second injection at the month 2 visit. After the injection, there were 3 minor adverse events (3.7%) and no serious adverse events. CONCLUSIONS: In patients considered ineligible for midurethral sling surgery, transurethral injection with polyacrylamide hydrogel may alleviate urinary incontinence symptoms. Repeat injections did not improve outcomes in this complicated group of patients.

Sublingual versus vaginal misoprostol for cervical dilatation 1 or 3 h prior to surgical abortion: a double-blinded RCT.

STUDY QUESTION: Can sublingual administration of misoprostol 1 h prior to vacuum aspiration be more effective than vaginal administration and as effective as either route three 3 h prior to surgery? SUMMARY ANSWER: Sublingually administered misoprostol is superior to vaginally administered misoprostol when given 1 h pre operatively, and it is as effective as after a three 3 h priming interval with either route of administration. WHAT IS KNOWN ALREADY: Misoprostol reduces complications and morbidity when used for cervical priming prior to surgical dilatation and vacuum aspiration in first trimester pregnancy. Despite the widespread use and extensive studies, the optimal route of administration of misoprostol before surgical abortion remains to be defined. The optimal priming interval after vaginal and sublingual administration of 400 mcg misoprostol has been reported to be 3 h. A longer interval will not improve dilatation but will increase the risk for bleeding and expulsion of the uterine contents before surgical evacuation. The pharmacokinetic properties of misoprostol indicate that sublingual compared with vaginal administration of misoprostol may result in a more rapid cervical priming effect. STUDY DESIGN, SIZE, DURATION: Women were randomized to four treatment groups and received 400 mcg misoprostol sublingually, or vaginally, 1 or 3 h prior to surgery. The study was a double-blinded RCT with regard to route of misoprostol administration but not the timing interval. The primary outcome was baseline cervical dilatation after misoprostol priming. The study was conducted between June 2007 and March 2014 and 184 women aged 18 years or older were recruited. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women were recruited among nulliparous women undergoing elective surgical first trimester abortion. Exclusion criteria were any contraindication for misoprostol, untreated genital infection, previous history of surgery to the cervix, or abnormal pregnancy. Gestational age was established by endovaginal ultrasound examination. The trial was conducted in a university hospital outpatient clinic. The allocated medication (misoprostol and placebo) was self-administered 1 h or 3 h prior to surgery. All women received 2 tablets of 200 mcg misoprostol and 2 identical looking placebo tablets. Prophylactic pain medication, 100 mg oral diclofenac, was administered at the time of misoprostol. Side effects were recorded immediately before surgery and women were asked which administration route of administration they found most convenient and which they would have preferred. The exact priming time (from misoprostol administration to initiation of dilatation) and signs of bleeding prior to dilatation were recorded. Vacuum aspiration was performed under general anaesthesia according to clinical routine. Dilatation was performed using tapered Pratt-dilatators and the resistance of the cervix was assessed objectively using a tonometer. All surgery was performed by two investigators, experienced in using the tonometer. The cumulative force required to dilate the cervix was calculated by adding the peak force needed for each dilatator up to 9.7 mm. The time needed for surgery including cervical dilatation and vacuum aspiration, was recorded. Intra-operative blood loss was measured and any surgical complications noted. MAIN RESULTS AND THE ROLE OF CHANCE: Six women were excluded retrospectively from the analysis. Multivariate analysis of the primary outcome baseline dilatation showed a significant influence on route of administration (P = 0.034, 95% confidence interval (CI) -2.202, -0.086) as well as the interaction variable between route of administration and total priming time (P = 0.042, 95% CI 0.00, 0.016), with the vaginal route becoming more effective with longer priming time. These factors also had a significant influence on the peak force (administration route P = 0.042, 95% CI 0.221, 12.427, interaction P = 0.049, 95% CI -0.089, 0.000) and cumulative force (administration route P = 0.023, 95% CI 3.142, 40.877, interaction P = 0.026, 95% CI -0.293, -0.019) used for dilatation. The total priming time had a significant influence on bleeding before surgery, with more women bleeding the longer the total priming time (P = 0.003, 95% CI 2.203, 49.706). For abdominal pain before surgery there was a significant influence of administration route (P = < 0.001 95% CI 0.028, 0.235) and the interaction variable between administration route and priming time (P = 0.003, 95% CI 2.005, 30.757) with more women in the sublingual group experiencing abdominal pain the longer the priming time. The groups did not differ regarding duration of surgery, amount of bleeding and rate of side effects, such as nausea and shivering. Women in our study preferred vaginal treatment, as they disliked the taste of the misoprostol tablets. Vaginal treatment was also perceived as quicker to administer (P = 0.0001). LIMITATIONS, REASONS FOR CAUTION: The cervical tissue has viscoelastic properties, i.e. tissue resistance to mechanical dilatation depends also on the rate at which dilatation is performed. The ideal measurement of dilatation force should therefore also record the rate and time of dilatation. To ensure comparability, only nulliparous women without prior cervical surgery were recruited. In addition, time of dilatation was recorded and did not differ between the groups, and it is therefore assumed that dilatation took place at approximately the same rate. A limitation is that the study was conducted over a long time period because there was only one tonometer, decreasing numbers of surgical abortions and the fact that the main author was on a rotation schedule. In addition, the study was not powered to detect differences in side effects. WIDER IMPLICATIONS OF FINDINGS: Priming with misoprostol is recommended prior to surgical abortion. The priming interval of misoprostol may be reduced to 1 h after sublingual administration but not after vaginal administration. The results of the present study will increase choice and flexibility in cervical priming. STUDY FUNDING/COMPETING INTERESTS: The Swedish research council (521-2009-2605), Swedish Council for Working Life and Social Research (1404/08), Stockholm County Council and Karolinska Institutet (ALF 2009-2012). All authors declare that they have no conflicts of interest. TRIAL REGISTRATION NUMBER: www.clincaltrials.gov, NCT 01933360.

Effect of letrozole on uterine tonus and contractility: a randomized controlled trial.

BACKGROUND: Letrozole inhibits estrogen production. It has been shown to increase efficacy in medical abortion when used with misoprostol. This study investigated if letrozole acts as an abortifacient due to a synergistic effect with misoprostol on uterine contractility. STUDY DESIGN: Sixteen healthy women requesting surgical abortion were randomized to receive either no pretreatment or treatment with letrozole 7.5 mg daily for 3 days prior to the abortion. All women received misoprostol 400 mcg vaginally 3.5 h prior to surgery. Intrauterine pressure was measured for 30 min before and 3.5 h after misoprostol was given using an intrauterine pressure catheter. Main outcome measure was uterine contractility analyzed by repeated-measures analysis of variance. RESULTS: At baseline, uterine contractions were absent and tonus was low. No significant difference was seen between the two groups in tonus (p=.818) or in contractility (p=.423) after misoprostol administration. CONCLUSION: Letrozole does not appear to act as an abortifacient through an effect on uterine contractility or increased sensitivity to misoprostol of the uterine myometrium.