The effect of the antiprogestin RU 486 on uterine contractility and sensitivity to prostaglandin and oxytocin

Short‐term efficacy and safety of early medical abortion in Japan: A multicenter prospective study

Purpose

To evaluate the short‐term efficacy and safety of a combined mifepristone‐misoprostol regimen in individuals seeking medical abortion at up to 63 days of gestational age.

Methods

This open‐label, multicenter, prospective study evaluated the short‐term efficacy and safety of medical abortion, with the primary outcome being the abortion success rate 24 h after misoprostol administration. The participants received 200 mg of mifepristone orally and 800 μg of misoprostol buccally in the hospital/clinic 36–48 h later. Bleeding and lower abdominal pain, which are the main symptoms associated with medical abortion, were recorded.

Results

The abortion success rate was 93.3% (95% confidence interval [CI]: 87.3–97.1%) within 24 h of misoprostol administration, 63.3% (95% CI: 54.05–71.94%) within 4 h, and 90.0% (95% CI: 83.18–94.73%) within 8 h. The median time from misoprostol administration to a successful abortion was 3.93 h. Bleeding was most commonly observed 0–4 h prior to the confirmation of gestational sac (GS) expulsion. The most intense lower abdominal pain occurred 0–1 h before the confirmation of GS expulsion.

Conclusion

The combined regimen of mifepristone and buccal misoprostol for medical abortion showed short‐term efficacy and a favorable safety profile.

Toxicity of abortifacients: A review for physicians in the post roe era

BACKGROUND

On June 24, 2022, the Supreme Court overturned Roe v. Wade, which will limit legal abortion in many areas of the U.S. Over half of abortions in the U.S. are performed using medication as opposed to surgical techniques. With widespread access to agents that are used for medication abortion, there may be an increase in emergency department presentations related to improper or unsupervised use of these medications.

METHODS

This narrative review focuses on the contraindications, adverse effects, and toxicities of the most common agents used for medication abortion in the U.S.

RESULTS

Medications included in this review are mifepristone, misoprostol, and methotrexate. Each of these medications has a unique adverse effect and toxicity profile.

CONCLUSION

Agents used for medication abortion have unique contraindications and adverse effects. Improper or unsupervised use may occur in the setting of limited abortion access and emergency medicine physicians are on the front lines in managing these presentations.

[Medical strategy for abortions between 14 and 16 weeks of gestation]

OBJECTIVE

To adapt the protocols for the management of voluntary termination of pregnancy following the new law extending the practice to 16 weeks of gestation.

MATERIAL AND METHOD

A systematic review of the literature in French and English concerning the management of patients requesting medically induced abortion was performed on PubMed, Cochrane Library and on the recommendations of international learned societies.

RESULTS

The efficacy of the medical method is greater than 95% when the protocols are adapted to the gestational age. The combination of mifepristone and misoprostol currently represents the "gold standard" of drug-based management. Mifepristone 200mg is sufficient, followed 24 to 48hours later by misoprostol 800μg administered sublingually or buccally. After the first dose, 400μg should be administered every 3hours buccally or sublingually until expulsion. Adverse effects (digestive and thermoregulatory disorders) during medical abortion are usually mild and short-lived. An anti-emetic treatment should be proposed as a prophylactic measure. For pain, ibuprofen is the analgesic treatment of choice, with the addition of level 2 analgesics if necessary.

CONCLUSION

Medical abortion is a safe and effective method up to 16 weeks of gestation, provided that the protocols, which differ according to gestational age, are respected. Women must be informed of the advantages and disadvantages of the methods according to the term and the side effects, which will allow them to choose the method that fits them best.

Mifepristone: A Safe Method of Medical Abortion and Self-Managed Medical Abortion in the Post-Roe Era

BACKGROUND

The U.S. Supreme Court's Dobbs v. Jackson Women's Health Organization decision on June 24, 2022 effectively overturned federal constitutional protections for abortion that have existed since 1973 and returned jurisdiction to the states. Several states implemented abortion bans, some of which banned abortion after 6 weeks and others that permit abortion under limited exceptions, such as if the health or the life of the woman is in danger. Other states introduced bills that define life as beginning at fertilization. As a result of these new and proposed laws, the future availability of mifepristone, one of two drugs used for medical abortion in the United States, has become the topic of intense debate and speculation.

AREAS OF UNCERTAINTY

Although its safety and effectiveness has been confirmed by many studies, the use of mifepristone has been politicized regularly since its approval. Areas of future study include mifepristone for induction termination and fetal demise in the third trimester and the management of leiomyoma.

DATA SOURCES

PubMed, Society of Family Planning, American College of Obstetrician and Gynecologists, the World Health Organization.

THERAPEUTIC ADVANCES

The use of no-touch medical abortion, which entails providing a medical abortion via a telehealth platform without a screening ultrasound or bloodwork, expanded during the COVID-19 pandemic, and studies have confirmed its safety. With the Dobbs decision, legal abortion will be less accessible and, consequently, self-managed abortion with mifepristone and misoprostol will become more prevalent.

CONCLUSIONS

Mifepristone and misoprostol are extremely safe medications with many applications. In the current changing political climate, physicians and pregnancy-capable individuals must have access to these medications.

Different dosing intervals of mifepristone-misoprostol for second-trimester termination of pregnancy: A meta-analysis and systematic review

OBJECTIVE

To compare 1- and 2-day drug administration interval between mifepristone and misoprostol for second-trimester pregnancy termination and provide evidence-based recommendations.

METHODS

Search strategy: the search was performed in Pubmed, EMBASE, and Cochrane Library for the relevant published studies from their establishment to March 2020.

SELECTION CRITERIA

randomized controlled trials (RCTs) comparing 1- and 2-day time interval of mifepristone-misoprostol for termination of pregnancy during second-trimester pregnancy were considered. Data were processed using Revman 5.3 software.

RESULTS

Meta-analyses of three RCTs showed no significant difference was reported in the induction-to-abortion time and successful abortion rate between 1- and 2-day mifepristone and misoprostol intervals. Statistical difference was not identified in the induction-to-abortion time between the two drug administration intervals in nulliparous or parous women.

CONCLUSIONS

Both 1- and 2-day dosing intervals between mifepristone and misoprostol are suitable for clinical use for second-trimester medical termination of pregnancy.

Efficacy of mifepristone - Prostaglandin analogue combination in medical termination of pregnancy up to and beyond 7 weeks of amenorrhea: The RYMMa study

OBJECTIVE

To assess, in real-life conditions, the success rate of the protocol mifepristone 600 mg / prostaglandin analogue (PG) in women requesting medical termination of pregnancy (MToP) either up to or beyond 7 weeks of amenorrhea (WA).

STUDY DESIGN

The study was performed between 2015 and 2016. This was a non-interventional prospective, multicentre, longitudinal study conducted in France, among a sample of public and/or private centres dealing with MToP. Characteristics of women, term of Mtop, modality of PG used were reported. The primary outcome was success of MToP, defined as complete abortion without surgical procedure.

RESULTS

A total of 893 pregnant women with less than the legal term of 14 WA were included in this study: 490 (54.9 %) ≤7 WA and 403 (45.1 %) >7 WA comprising 29 > 9 WA. The mean age of women was 28.1 ± 6.8 years and the one of pregnancy was 7.0 WA ± 1.3 WA. The most frequently used PG combined to mifepristone 600 mg was misoprostol 400 μg (57.0 % ≤7 WA and 35.1 % >7 WA) or 800 μg per os (oral or oral transmucosal) (27.5 % ≤7 WA and 40.1 % >7 WA). Vaginal misoprostol (6.4 %, N = 48) and gemeprost (5.2 %, N = 39) were less used. In women ≤7 WA (N = 422) and women >7 WA (N = 354) for whom result of the MToP was collected, success rates were 94.5 % (95 %CI 91.9 %-96.5 %) and 92.4 % (95 %CI 89.1 %-94.9 %), respectively (p = 0.219). In multivariate regression analysis, three factors were significantly associated with a higher risk of MToP failure: increased number of previous pregnancies (OR = 1.233; 95 %CI 1.086-1.401 for one pregnancy), increased number of previous surgical ToPs (OR = 1.563; 95 %CI 1.036-2.359 for one ToP) and increased interval between mifepristone and PG intake (OR = 1.061; 95 %CI 1.012-1.112 for one hour). Term of pregnancy (OR = 1.497; 95 %CI 0.833-2.690 for ≤7 WA vs >7WA), administration route (OR = 1.553; 95 %CI 0.488-4.936 for oral vs oral transmucosal; and OR = 1.216; 95 %CI 0.625-2.366 for vaginal vs oral transmucosal), and dose of misoprostol (OR = 1.000; 95 %CI 0.999-1.001), were not associated with the risk of failure. Overall, tolerance was good.

CONCLUSION

This study showed, in real-life settings, a high rate of success for MToP using mifepristone 600 mg, independent of the pregnancy term and the therapeutic protocol used. MToP was safe and well tolerated however only a small number of women beyond 9 WA have been included.

Medication Abortion Up to 70 Days of Gestation

Medication abortion, also referred to as medical abortion, is a safe and effective method of providing abortion. Medication abortion involves the use of medicines rather than uterine aspiration to induce an abortion. The U.S. Food and Drug Administration (FDA)-approved medication abortion regimen includes mifepristone and misoprostol. The purpose of this document is to provide updated evidence-based guidance on the provision of medication abortion up to 70 days (or 10 weeks) of gestation. Information about medication abortion after 70 days of gestation is provided in other ACOG publications [1].

Cervical maturation using mifepristone in women with normal pregnancies at or beyond term

OBJECTIVE

The aim of our study was to evaluate the efficacy and safety of oral mifepristone use for cervical ripening and the initiation of labor in women with normal pregnancies at or beyond term.

STUDY DESIGN

We conducted a monocentric, prospective, comparative study on the induction of labor in women with an unfavorable cervix after 37 or more weeks of gestation in the Franck Joly Hospital, French Guiana. The immediate induction of labor by mifepristone was compared to expectant management and the induction of labor with routine cervical ripening agents during two consecutive periods. During the first period, patients received mifepristone (600 mg orally at the moment of enrollment) and were evaluated after 48 h. In the second period, patients did not receive any drugs and were evaluated after 48 h of expectant management.

PRIMARY OUTCOMES

Spontaneous labor or a Bishop Score ≥6 within 48 h of mifepristone administration.

SECONDARY OUTCOMES

enrollment-induction to delivery interval, rate of failed induction, doses of prostaglandin used, mode of delivery, requirement of oxytocin augmentation, and neonatal outcomes.

RESULTS

This study enrolled 231 women, 108 in the first and 123 in the second period undergoing induced labor at term caused by various obstetric conditions. There were no significant differences between groups for age, body mass index, gravida, parity, the initial Bishop Score, scarred uterus, or post-term pregnancy. There were statistically significant differences between the two groups concerning spontaneous labor and/ or a Bishop Score ≥6 within 48 h (p < 10-3) and received doses of misoprostol (p = 0.01). Patients receiving mifepristone were 10 times more likely to be in labor after 48 h of inclusion (RR = 9.98, CI 95 % = [4.47-22.29]). The enrollment-induction to delivery interval was significantly shorter for the mifepristone group (p < 0.001). There were no other differences in mode of delivery, placenta abnormalities or neonatal outcomes.

CONCLUSION

Mifepristone efficiently induced cervical ripening and labor initiation in women with normal pregnancies at or beyond term. It may offer an alternative method to the classic induction especially for patients seeking spontaneous labor.

A comparison between labor induction with only Dilapan-S and a combination of mifepristone and Dilapan-S in nulliparous women: a prospective pilot study

OBJECTIVE

The aim of our study was to determine whether the combination of mifepristone and the osmotic dilator Dilapan-S improves the labor induction outcomes as compared to Dilapan-S alone.

METHODS

This prospective comparative study included 127 eligible women, of whom 58 underwent cervical ripening with Dilapan-S (12-h exposure, the control group) and 69 with Dilapan-S, with a concurrent pretreatment of 200 mg oral mifepristone (the study group), 8 h before Dilapan-S insertion.

RESULTS

The vaginal delivery rate in the control group and the study group was 60.3 and 76.8% (p = .045), respectively; the induction to delivery interval was 22.74 ± 3.01 h and 19,890 ± 2.42 h (p < .001), respectively; and the number of births within 24 h was 43.1 and 73.9% (p < .001), respectively. There was no difference in the rate of failed labor induction (6.9 versus 8.7%, p = .939). The Bishop's score improved significantly after the combined treatment as compared to with Dilapan alone (3.10 ± 0.58 versus 4.03 ± 1.35, p < .001). Moreover, in the study group, labor started earlier and proceeded faster with a lower additional oxytocin usage for labor induction or augmentation. There were no differences in the operative delivery rate and the perinatal outcomes. There were no adverse side effects of both mifepristone and Dilapan-S.

CONCLUSION

Our study is the first one to show that in comparison to labor induction using only osmotic dilators Dilapan-S, the combination of mifepristone and Dilapan-S is more efficient in terms of improving cervical ripening and vaginal delivery rate and reducing labor duration and frequency of oxytocin augmentation. The results revealed that this combined method is safe and has no immediate adverse effects on newborns. More studies are needed to evaluate what clinical cases are the most appropriate for the application of this combined method, considering the parity, degree of cervical ripening, and indication for labor induction.

Adjunctive Agents for Cervical Preparation in Second Trimester Surgical Abortion

Late second trimester dilation and evacuation is a challenging subset of surgical abortion. Among the reasons for this is the degree of cervical dilation required to safely extricate fetal parts. Cervical dilation is traditionally achieved by placing multiple sets of osmotic dilators over two or more days prior to the evacuation procedure; however, there is interest in shortening cervical preparation time. The use of adjuvant mifepristone and misoprostol in conjunction with osmotic dilators has been studied for this purpose, and their use demonstrates that adequate cervical dilation can be achieved in less time than with dilators alone. We present a review of the current evidence surrounding adjunctive agents for cervical preparation, and contend that for women presenting for surgical abortion care above 19 weeks gestation, the use of adjunctive mifepristone and/or misoprostol should be strongly considered along with osmotic dilator insertion when cervical preparation in less than 24 h is needed.

Progesterone for preventing pregnancy termination after initiation of medical abortion with mifepristone

INTRODUCTION

Abortion is often a difficult and traumatic decision for a woman to make. Perhaps greater distress occurs when a woman commences a medical abortion but then changes her mind and wishes to keep the now-threatened pregnancy. One published case series detailed a potential method to counter/reverse the abortifacient effect of mifepristone by administering parenteral progesterone in such situations.

OBJECTIVES

The present report details cases of women in similar circumstances who have been treated with progesterone. The aims were to document occurrences of where women have changed their mind after commencing medical abortion, as well as to explore some of the controversies and clinical issues surrounding their circumstances.

METHODS

Women who had commenced medical abortion by ingesting mifepristone but who had not taken misoprostol independently contacted a national pregnancy support service the same day. Those meeting criteria for treatment received progesterone pessaries per vaginum for two weeks.

RESULTS

Cases: 28-year-old woman, 6 weeks plus 1 day gestation; 35-year-old woman, 8 weeks plus 5 days gestation; and 27-year-old woman, 7 weeks plus 3 days gestation. Outcomes respectively were: healthy male baby delivered at 39 weeks gestation; healthy male baby delivered at term; and completed medical abortion.

CONCLUSIONS

Women have changed their mind after commencing medical abortion. Progesterone use in early pregnancy is low risk and its application to counter the effects of mifepristone in such circumstances may be clinically beneficial in preserving her threatened pregnancy. Further research is required, however, to provide definitive evidence.

Development of medical termination of pregnancy: a review

The synthesis of mifepristone, an antiprogestin blocking the action of progesterone at the receptor level, started a new era of medical termination of pregnancy (MTOP). The initial results of MTOP with mifepristone alone were disappointing; however, mifepristone can sensitise the myometrium to the action of prostaglandins. Clinical trials have shown that the sequential administration of mifepristone followed 1-2 days later by a prostaglandin analogue is a safe, effective, and acceptable method for MTOP. This article will review the events and challenges leading to the development of the current evidence-based and yet off-label regimen for first-trimester MTOP.

TWEETABLE ABSTRACT

This article reviews the events and challenges in the development of medical termination of pregnancy.

Outcomes of mifepristone usage for cervical ripening and induction of labour in full-term pregnancy. Randomized controlled trial

OBJECTIVE

The most commonly used approved indications for mifepristone in obstetrics include: termination of early pregnancy, cervical dilatation prior to abortion, labour induction in case of fetal death in utero. Fewer studies have been conducted on the effect of mifepristone on cervical ripening and induction of labour in term pregnancy with a live fetus. The aim of our study was to evaluate efficacy and safety of mifepristone use for cervical ripening and induction of labour versus expectant management in full-term pregnancy.

STUDY DESIGN

Randomized controlled trial. 149 women were randomized, 74 for cervical ripening and induction with mifepristone (200mg orally at the moment of enrollment and, if applicable, second dose after 24h), 75 - expectant management. Primary outcomes: gain in Bishop Score within 24 and 48-h of mifepristone; number of women going into spontaneous labor within 24, 48 and 72-h of mifepristone; rate of failed induction or expectant management.

SECONDARY OUTCOMES

enrollment-induction to delivery interval; mode of delivery; requirement of oxytocin augmentation, neonatal outcomes.

RESULTS

After 48h from enrollment mean gain in Bishop score was 2.58±1.33 in the induction group and 1.15±0.97 in the expectant group (<0.001). Failed management rate was 5.41% and 2.67%, respectively. Significantly more mifepristone treated women had labour within 24, 48 and 72h from enrollment (RR 15.20 CI 95% 2.06-112.18; RR 6.08 CI 95% 2.73-13.57; RR 2.14 CI 95% 1.04-4.42) (p<0.05). Enrollment-induction to delivery interval was significantly shorter in mifepristone group: 2.69±2.06 vs 3.77±1.86days (p<0.001). Premature rupture of membranes, meconium-stained amniotic fluid were more common in expectant management, but regional analgesia and cephalopelvic disproportion - in induction group. There were no differences in mode of delivery, requirement of oxytocin augmentation and main neonatal outcomes.

CONCLUSION

Mifepristone was efficient on inducing cervical ripening and labour in full-term pregnancy. There were no significant difference in main maternal and neonatal outcomes between mifepristone use and expectant management. There were no serious adverse side effects of mifepristone, but there were some features of the course of labor, like more painful uterine contractions and trend of higher rate of cephalopelvic disproportion, that might be directly related to the mifepristone action.

[Methods of induction of labor in termination of pregnancy after 22weeks: About 3procedures]

OBJECTIVES

To propose a protocol for induction of labor to terminate pregnancy after 22weeks of amenorrhea allowing to decrease the duration of labor and of hospitalization but also, allowing to reduce the number of emergency pretreatment-induced fetal death, to improve the experience of the patients and to limit the cost.

METHODS

We realized a retrospective single-center study including 269patients and comparing three protocols, with and without laminaria and with various intervals mifepristone-misoprostol (14 and 38hours). The outcome measures were the misoprostol-delivery interval, the delivery time and the number of emergency pretreatment-induced fetal death.

RESULTS

We showed that the misoprostol-delivery interval and the delivery time were comparable for the three periods of our study, even after decrease of 24hours of the mifepristone-misoprostol interval and in the absence of laminaria. The misoprostol-delivery interval was between 7h30 and 8h35 between protocols (P=0.055). The delivery time was between 5:18pm and 6:48pm between protocols (P=0.252). The early administration of misoprostol allowed the patients to give birth earlier (P=0.001). Finally, we showed that the increase of the size and the number of laminarias were risk factors of emergency pretreatment-induced fetal death (respectively P=0.013 and P=0.002).

CONCLUSION

The absence of laminaria and the reduction of the interval mifepristone-misoprostol of 24hours do not change the time to delivery and allow to reduce the duration of hospitalization, the number of emergency pretreatment-induced fetal death and the cost of the TOP.

A Comparative Study of Misoprostol Only and Mifepristone Plus Misoprostol in Second Trimester Termination of Pregnancy

OBJECTIVE

To compare the effectiveness, success rate and induction to abortion interval between administration of misoprostol only and mifepristone with misoprostol in second trimester abortions (14-20 weeks) .

MATERIALS AND METHODS

The study was conducted by dividing women approaching for second trimester termination, into two groups each consisting of 100 women. Group-I received only misoprostol; 600 mcg initial vaginal insertion followed by 400 mcg sublingually every 3 h until termination. Women in Group-II received mifepristone 200 mg and after 24 h started with 600 mcg misoprostol, per vaginal followed by 400 mcg sublingually till abortion was completed, up to a maximum of five doses in both groups.

RESULTS

The success rate in Group-I was 89 %, whereas in Group-II it was 96 %. The mean induction abortion interval in Group-I was 10.67 ± 3.96 h compared to Group-II which was significantly less 6.19 ± 2.70 h (p value < 0.01). The mean dose of misoprostol in Group-I was 1610 ± 511.18 mcg and in Group-II, it was lesser 1046 ± 392.71 mcg (p value < 0.01). There was significant difference in the mean blood loss also, 97.20 ± 36.35 ml in Group-I and 52.55 ± 27.96 ml in Group-II. Also among the individual groups multigravidae and lower gestational age (<17 weeks), women had lesser IAI as well as lesser misoprostol dose was required.

CONCLUSION

Pretreatment with mifepristone significantly reduces the induction abortion interval and the misoprostol dose along with minimal blood loss.

Cervical dilation before first-trimester surgical abortion (<14 weeks' gestation)

First-trimester surgical abortion is a common, safe procedure with a major complication rate of less than 1%. Cervical dilation before suction abortion is usually accomplished using tapered mechanical dilators. Risk factors for major complications in the first trimester include increasing gestational age and provider inexperience. Cervical priming before first-trimester surgical abortion has been studied using osmotic dilators and pharmacologic agents, most commonly misoprostol. Extensive data demonstrate that a variety of agents are safe and effective at causing preoperative cervical softening and dilation; however, given the small absolute risk of complications, the benefit of routine use of misoprostol or osmotic dilators in first-trimester surgical abortion is unclear. Although cervical priming results in reduced abortion time and improved provider ease, it requires a delay of at least 1 to 3 h and may confer side effects. The Society of Family Planning does not recommend routine cervical priming for first-trimester suction abortion but recommends limiting consideration of cervical priming for women at increased risk of complications from cervical dilation, including those late in the first trimester, adolescents and women in whom cervical dilation is expected to be challenging.

Off-label use of misoprostol in gynaecology

Clinical use of drugs is approved for specified clinical indication, route of administration, dose and population group. Off-label prescribing of a registered medicine occurs outside of these parameters and may be justified by pharmacology and physiology, as well as sufficient evidence from published clinical trials and reviews. Misoprostol and mifepristone in combination have recently been registered in Australia for medical termination of pregnancy in women of child-bearing age. There is good clinical evidence for efficacy and safety of misoprostol in uterine evacuation in both miscarriage and termination of pregnancy. The pharmacological effects of misoprostol on the uterus and clinical outcomes in both early miscarriage and abortion are comparable. Medical management of miscarriage with misoprostol in Australia is performed off-label. A woman presenting with first trimester miscarriage must be clearly informed that use of misoprostol in her case is for a non-approved indication. This raises the issue of inequity in her management compared with that of first trimester medical abortion, including being treated off-label and the potential cost of non-subsidised medication. The clinician must also be careful to use an evidence-based protocol that would withstand medicolegal challenge in the case of an adverse outcome.

Early versus late misoprostol administration after mifepristone for medical abortion

PURPOSE

To evaluate the successful medical termination of pregnancy comparing two regimens: misoprostol 2 or 48 h after mifepristone administration.

DESIGN

Prospective randomized study.

SETTING

Department of Obstetrics and Gynecology.

SAMPLE

One hundred pregnant women admitted for medical termination of pregnancy were enrolled; no pregnancies were over 55 days gestational age.

METHODS

All subjects were randomly assigned for misoprostol administration either 2 or 48 h after mifepristone. All participants underwent transvaginal ultrasound examination for uterine contents 48 h and 3 weeks after mifepristone.

MAIN OUTCOME MEASURE

Procedure failure, defined as the presence of fetal heart activity, presence of a gestational sac, or a need for uterine curettage after misoprostol administration.

RESULTS

Each group consisted of 50 women. Fetal heart activity was significantly more frequent after 48 h in the 2-h interval group (10/50) than in the 48-h interval group (0/50) (p = 0.002). Three weeks after misoprostol administration, fetal heart activity was present in 4/50 (8 %) in the 2-h interval group (p = 0.118) and none of the 48-h interval group. At 48 h residual tissue was present in 13/50 (26 %) and 5/50 (10 %) in the 2 and 48-h interval groups, respectively (p = 0.031); this was reduced to 12/50 (24 %) compared to 5/50 (10 %) in the two groups, respectively (p = 0.054) after 3 weeks.

CONCLUSIONS

Successful medical termination of pregnancy can be achieved using misoprostol administration 2 h after mifepristone in 76 % of cases. However, this regimen is not recommended as it is significantly inferior to the traditional 48-h interval regimen.

[Medical termination of pregnancy in a patient with severe cystic fibrosis. Possible effect of the antiglucocorticoid action of mifepristone on the respiratory disease]

Better management of patients with cystic fibrosis has resulted in an increased rate of pregnancy, especially in mild forms. In case of severe respiratory impairment, physiological changes occurring during pregnancy can be life threatening. Medical termination of pregnancy may be necessary. We report a case of severe cystic fibrosis requiring a termination of pregnancy due to significant maternal risk at 17 weeks of gestation. Mifepristone used for induction of labor has a well-known antiglucocorticoid action. We discuss here its potential effect on the onset of an acute pulmonary failure in this patient with long-term corticosteroid therapy.

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.

Mifepristone (RU 486) induces vasodilation and inhibits platelet aggregation: nongenomic and genomic action to cause hemorrhage

BACKGROUND

The regimen mifepristone/misoprostol is an established and highly effective method for early termination of pregnancy. However, its side effects such as a significantly long bleeding time and hemorrhage have been scantly studied.

STUDY DESIGN

Human umbilical artery (HUA) from pregnant women undergoing elective cesarean section at term and rat thoracic aorta (RTA) were isometrically recorded. The vasorelaxing effect of mifepristone was analyzed on the contractile responses induced by KCl or serotonin (5-HT); moreover, the potential response of mifepristone on adenosine diphosphate (ADP)-induced human platelet aggregation was also evaluated.

RESULTS

This study describes that mifepristone elicits (1) rapid and reversible vasorelaxation on KCl- or 5-HT-induced contraction in HUA and RTA with and without endothelium and (2) immediate prevention of ADP-induced human platelet aggregation.

CONCLUSIONS

These effects seem to be responsible for increased and prolonged hemorrhage. Since mifepristone-prevented platelet aggregation was observed in the anucleate platelets, and mifepristone-induced vasorelaxation remained unaffected in de-endothelized tissues, by inhibitors of transcription and translation and a nitric oxide (NO) synthase inhibitor, a nongenomic endothelium- and NO-independent mechanism was revealed. Additionally, the results indicated a blockade of voltage- and receptor-operated calcium channels. The antiglucocorticoid genomic action of mifepristone, by inducing an excess of NO, may also contribute to exacerbated hemorrhage.

Characterization of the myometrial transcriptome and biological pathways of spontaneous human labor at term

AIMS

to characterize the transcriptome of human myometrium during spontaneous labor at term.

METHODS

myometrium was obtained from women with (n=19) and without labor (n=20). Illumina HumanHT-12 microarrays were utilized. Moderated t-tests and false discovery rate adjustment of P-values were applied. Real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was performed for a select set of differentially expressed genes in a separate set of samples. Enzyme-linked immunosorbent assay and Western blot were utilized to confirm differential protein production in a third sample set.

RESULTS

1) Four hundred and seventy-one genes were differentially expressed; 2) gene ontology analysis indicated enrichment of 103 biological processes and 18 molecular functions including: a) inflammatory response; b) cytokine activity; and c) chemokine activity; 3) systems biology pathway analysis using signaling pathway impact analysis indicated six significant pathways: a) cytokine-cytokine receptor interaction; b) Jak-STAT signaling; and c) complement and coagulation cascades; d) NOD-like receptor signaling pathway; e) systemic lupus erythematosus; and f) chemokine signaling pathway; 4) qRT-PCR confirmed over-expression of prostaglandin-endoperoxide synthase-2, heparin binding epidermal growth factor (EGF)-like growth factor, chemokine C-C motif ligand 2 (CCL2/MCP1), leukocyte immunoglobulin-like receptor, subfamily A member 5, interleukin (IL)-8, IL-6, chemokine C-X-C motif ligand 6 (CXCL6/GCP2), nuclear factor of kappa light chain gene enhancer in B-cells inhibitor zeta, suppressor of cytokine signaling 3 (SOCS3) and decreased expression of FK506 binding-protein 5 and aldehyde dehydrogenase in labor; 5) IL-6, CXCL6, CCL2 and SOCS3 protein expression was significantly higher in the term labor group compared to the term not in labor group.

CONCLUSIONS

myometrium of women in spontaneous labor at term is characterized by a stereotypic gene expression pattern consistent with over-expression of the inflammatory response and leukocyte chemotaxis. Differential gene expression identified with microarray was confirmed with qRT-PCR using an independent set of samples. This study represents an unbiased description of the biological processes involved in spontaneous labor at term based on transcriptomics.

In vitro comparison of myometrial contractility induced by aglepristone-oxytocin and aglepristone-PGF2alpha combinations at different stages of the estrus cycle in the bitch

The aim of this in vitro study was to compare the uterokinetic activity of oxytocin and dinoprost, the natural PGF2α, with or without aglepristone, in canine myometrial fibers. Thirty-three bitches were allocated into one of four groups, depending on their estrous stage and whether or not they had received a treatment with aglepristone (metestrus aglepristone, n = 5; metestrus without treatment, n = 9; anestrus aglepristone, n = 9; anestrus without treatment, n = 10). After hysterectomy, longitudinal and circular uterine strips were mounted in organ baths. Oxytocin or PGF2α (10 nmol/l to 10 micromol/l) were applied non-cumulatively. A linear mixed effects models theory was used to compare the fiber effect, the aglepristone effect, and the treatment effect, from the area under the curves calculated from the contractile effect/concentration curves for each drug. Oxytocin and PGF2α induced concentration-dependent myometrial contractions in longitudinal (LF) and circular myometrial fibers (CF), indicating the presence of functional contractile oxytocin- and PGF2α-receptors in metestrus and anestrus. The contractile response to oxytocin was greater in LF than in CF in all of the groups; the response to PGF2α was greater in LF than in CF in non-treated bitches in anestrus and in treated bitches in metestrus. These results suggest that there is a difference in sensitivity or a heterogeneous distribution of oxytocin and PGF2α-receptors in the myometrial layers, which is independent of hormonal impregnation. The contractile response to oxytocin and PGF2α was significantly increased after aglepristone treatment in LF during metestrus, suggesting that the progesterone withdrawal induced by aglepristone has a role to play. The longitudinal myometrial layer also appeared to be the target for the two drugs at this stage. This study provides new information about canine uterine contractile activity, notably the differing behavior of myometrial CF and LF; in vivo studies are required to test the use of a combination of aglepristone and oxytocin in the treatment of canine pyometra.

Nongenomic uterine relaxing effect of RU 486 (mifepristone) prior to its antiprogesterone activity in the human pregnancy

The antiprogestin mifepristone (RU 486) is used for termination of pregnancy, as RU 486 blocks the quiescent action of progesterone, increases uterine contractility, sensitizes the myometrium to prostaglandins, and elicits cervical ripening. Since RU 486 represents a class of compound that is structurally related to steroid hormones, some of which possess a nongenomic uterine relaxing effect, we investigated the potential nongenomic relaxing action of RU 486 on the human pregnant myometrium. Myometrial tissues were obtained from pregnant women undergoing elective cesarean section at term and were isometrically recorded. RU 486 caused relaxation on spontaneous contractility and high potassium-induced contractions with lower relaxing efficacy than progesterone. The progesterone receptor-blocking activity of RU 486 did not antagonize the uterine relaxation of progesterone. Moreover, contractions induced by oxytocin or different prostaglandins (PGF(2alpha), PGE(2), and a prostaglandin analogue, misoprostol) were inhibited rather than increased by RU 486. RU 486 induced a rapid and reversible relaxing effect, which was unaffected by inhibitors of protein synthesis and transcription, implying that RU 486 acts through a nongenomic mechanism. This study reveals that RU 486: (i) reduced high potassium-induced contraction and prevented calcium-induced contraction in depolarized tissue; and (ii) relaxed the oxytocin- and prostaglandin-induced contractions, indicating a blockade of voltage- and receptor-operated calcium channels by RU 486. These data show that this antiprogestin may induce a rapid nongenomic antiuterotonic effect prior to its antiprogesterone action.

PROGESTERONE AND THE CONTROL OF HUMAN PREGNANCY AND PARTURITION

Almost 80 years ago George Corner and colleagues provided the first evidence that progesterone maintains pregnancy and that it does so, at least in part, by promoting myometrial relaxation. In the 1950s, Arpad Csapo proposed the “progesterone block hypothesis”, which posits that progesterone maintains pregnancy by promoting myometrial relaxation and that its withdrawal initiates a cascade of hormonal interactions that transforms the myometrium to a highly contractile state leading to the onset of labour. Csapo later proposed that contractility of the pregnant myometrium is determined by the balance between relaxation induced by progesterone and contraction induced by a cohort of signals including oestrogens, uterine distention and stimulatory uterotonins such as prostaglandins (PGs) and oxytocin (OT). According to this “seesaw” hypothesis, progesterone promotes myometrial relaxation by directly inducing relaxation and/or by inhibiting the production of, or myometrial responsiveness to, stimulatory uterotonins. These landmark concepts, though derived from studies of experimental animals, form the foundation for current understanding of progesterone's role in the physiology of human pregnancy. Remarkable progress has been made over the last 20–30 years in understanding the signal transduction pathways through which steroid hormones affect target cells. This knowledge has broadened the scope of Csapo's original paradigms and we are now beginning to unravel the specific signaling pathways and molecular interactions by which progesterone affects human myometrium and how its actions are controlled at the functional level. This is important for the development of progestin-based therapeutics for the prevention or suppression of preterm labour and preterm birth. Here we review recent progress in understanding the mechanisms by which progesterone sustains pregnancy and in particular how it promotes myometrial relaxation, how its relaxatory actions are nullified at parturition, and the hormonal interactions that induce progesterone withdrawal to determine the timing of human birth.

Antifertility effects of antigestogens

Since the discovery of the structure and function of steroids over 60 years ago, it has long been recognized that synthetic antagonists of the natural hormones would have potential therapeutic uses. Antagonists of mineralocorticoids, androgens and oestrogens, for example spironolactine, cyproterone, flutamide and tamoxifen, have already found a place in the management of hormone dependent conditions. In 1982, chemists at Roussel UCLAF announced that they had synthesized mifepristone (RU486) 17β-hydroxy-11(p-(dimethylamino)phenyl)-17-(1-propynyl) estra-411, 9-dien-3-one) a derivative of norethindrone which had potent antiprogestogenic as well as antiglucocorticoid activity. Although it was immediately realised that this compound would potentially have wide clinical application, its development in the last 10 years has been dominated by its abortifacient action. In the original clinical report by Herrman and colleagues it was shown that bleeding occurred when it was given to female volunteers in the second half of the menstrual cycle. In addition, complete abortion occurred in eight of 11 women who took the drug in the early weeks of pregnancy. These findings, which demonstrated that mifepristone could be used as the basis of a medical method of inducing abortion, were immediately made the focus of groups opposed to abortion on moral grounds. Experience over the last 10 years has confirmed the promise of these early studies and mifepristone, in combination with a suitable prostaglandin, is now licensed in France, UK and Sweden for use as a medical method of inducing abortion in early pregnancy.

Second trimester medical abortion with mifepristone-misoprostol and misoprostol alone: a review of methods and management

Second trimester abortions constitute 10-15% of all induced abortions worldwide but are responsible for two-thirds of major abortion-related complications. During the last decade, medical methods for second trimester induced abortion have been considerably improved and become safe and more accessible. Today, in most cases, safe and efficient medical abortion services can be offered or improved by minor changes in existing health care facilities. Second trimester medical abortion can be provided by a nurse-midwife with the back-up of a gynaecologist. Because of the potential for heavy vaginal bleeding and serious complications, it is advisable that second trimester terminations take place in a health care facility where blood transfusion and emergency surgery (including laparotomy) are available. This article provides basic information on regimens recommended for second trimester medical abortion. The combination of mifepristone and misoprostol is now an established and highly effective method for second trimester abortion. Where mifepristone is not available or affordable, misoprostol alone has also been shown to be effective, although a higher total dose is needed and efficacy is lower than for the combined regimen. Therefore, whenever possible, the combined regimen should be used. Efforts should be made to reduce unnecessary surgical evacuation of the uterus after expulsion of the fetus. Future studies should focus on improving pain management, the treatment of women with failed medical abortion after 24 hours, and the safety of medical abortion regimens in women with a previous caesarean section or uterine scar.

Surgical versus medical methods for second trimester induced abortion

BACKGROUND

Determining the optimal method of performing second-trimester abortions is important, since they account for a disproportionate amount of abortion-related morbidity and mortality.

OBJECTIVES

To compare surgical and medical methods of inducing abortion in the second trimester of pregnancy with regard to efficacy, side effects, adverse events, and acceptability.

SEARCH STRATEGY

We identified trials using Pub Med, EMBASE, POPLINE, and the Cochrane Central Register of Controlled Trials (CENTRAL). We also searched the reference lists of identified studies, relevant review articles, book chapters, and conference proceedings for additional, previously unidentified studies. We contacted experts in the field for information on other published or unpublished research.

SELECTION CRITERIA

Randomised trials comparing any surgical to any medical method of inducing abortion at >/= 13 weeks' gestation were included.

DATA COLLECTION AND ANALYSIS

We assessed the validity of each study using the methods suggested in the Cochrane Handbook. Investigators were contacted as needed to provide additional information regarding trial conduct or outcomes. Two reviewers abstracted the data. Odds ratios and 95% confidence intervals were calculated for dichotomous variables using RevMan 4.2. The trials did not have uniform interventions, therefore, we were unable to combine them into a meta-analysis.

MAIN RESULTS

Two studies met criteria for this review. One compared dilation and evacuation (D&E) to intra-amniotic instillation of prostaglandin F(2) (alpha). The second study compared D&E to induction with mifepristone and misoprostol. Compared with prostaglandin instillation, the combined incidence of minor complications was lower with D&E (OR 0.17, 95% CI 0.04-0.65) as was the total number of minor and major complications (OR 0.12, 95% CI 0.03-0.46). The number of women experiencing adverse events was also lower with D&E than with mifepristone and misoprostol (OR 0.06, 95% CI 0.01-0.76). Although women treated with mifepristone and misoprostol reported significantly more pain than those undergoing D&E, efficacy and acceptability were the same in both groups. In both trials, fewer subjects randomised to D&E required overnight hospitalisation.

AUTHORS' CONCLUSIONS

Dilation and evacuation is superior to instillation of prostaglandin F(2) (alpha). The current evidence also appears to favour D&E over mifepristone and misoprostol, however larger randomised trials are needed.

Mifepristone versus laminaria: a randomized controlled trial of cervical ripening in midtrimester termination

BACKGROUND

Mifepristone was compared with laminaria for cervical ripening in second-trimester induction of labor (IOL).

STUDY DESIGN

We performed a randomized, controlled, open-label study of women undergoing second-trimester IOL for fetal demise, aneuploidy or anomalies at a single tertiary care center from January 2004 to May 2006. Main outcome measures were induction-to-delivery time and pain with cervical ripening.

RESULTS

Of 50 eligible women, 37 were enrolled in the study, of whom 33 completed the study: 16 were randomized to laminaria and 17 to mifepristone. Induction-to-delivery time was significantly shorter in the mifepristone arm (mean=10 h vs. 16 h, p=.01; median=7.5 h vs. 13.4 h, p=.01). Pain with cervical ripening was also significantly less in the mifepristone group than in the laminaria group (median=1 vs. 6 on an 11-point visual analogue scale, p<.001). Maternal age, parity, gestational age, fetal demise prior to induction, need for postpartum curettage, blood loss, pain during induction, delivery and at the time of discharge were not significantly different between the two groups.

CONCLUSION

Mifepristone shortens the induction-to-delivery time and decreases pain with cervical ripening when compared with laminaria for second-trimester induction.

Uterine Activity after Oral Mifepristone Administration in Human Pregnancies beyond 41 Weeks’ Gestation

BACKGROUND/AIM

To examine the effect of oral mifepristone on uterine activity in postterm human pregnancies.

METHODS

As part of a randomized, placebo-controlled trial comparing 200 mg oral mifepristone to placebo for preinduction cervical ripening in women with well-dated pregnancies beyond 41 weeks' gestation with unfavorable cervices, uterine activity was continuously recorded with external tocodynamometry and contraction frequency tabulated.

RESULTS

Ninety-seven women received mifepristone and 83 women received placebo. Uterine activity (uterine contractions/hour) was greater in the mifepristone than in the placebo group between 7 h (8.03 +/- 0.48 vs. 5.90 +/- 0.39, p = 0.001) and 24 h (8.53 +/- 0.68 vs. 6.61 +/- 0.46, p = 0.02) after dosing.

CONCLUSION

Oral mifepristone administration to women with pregnancies beyond 41 weeks increases uterine activity in the absence of externally administered uterotonic agents.

Oral mifepristone and buccal misoprostol administered simultaneously for abortion: a pilot study

BACKGROUND

Simultaneous oral mifepristone and vaginal misoprostol has a 24-h expulsion rate of approximately 90% when used for abortion through 63 days' gestation. This pilot study sought to determine if a simultaneous regimen using buccal misoprostol would be similarly effective and merit further investigation.

STUDY DESIGN

One hundred twenty women were enrolled into three equal groups by gestational age: < or =49 days (Group 1), 50-56 days (Group 2) and 57-63 days (Group 3). After swallowing 200 mg of mifepristone, subjects received 800 mcg buccal misoprostol. Participants returned in 24+/-1 h for evaluation of expulsion by ultrasonography. Women with a persistent gestational sac received 800 mcg vaginal misoprostol. Further follow-up occurred at 1, 2 and 5 weeks by telephone or in person, as appropriate. Sample sizes for each group were estimated with the aim of establishing a 24-h expulsion rate of 90% (95% CI=76-95).

RESULTS

The 24-h expulsion rates for Groups 1, 2 and 3 were 73% (95% CI=56-85), 69% (95% CI=52-83) and 73% (95% CI=56-85), respectively. Common side effects were nausea (62%), vomiting (33%) and diarrhea (48%), which did not differ by gestational age. Forty-three percent of subjects found the taste of buccal misoprostol objectionable; 30% found buccal retention uncomfortable or inconvenient, and 10% reported oral irritation, sensitivity, numbness or oral ulcers.

CONCLUSIONS

Simultaneous oral mifepristone and buccal misoprostol had a lower-than-hypothesized expulsion rate at 24 h. Although overall success rates at 7 or 15 days could have been higher than those observed at 24 h, we believe that this regimen does not warrant further study.

Cervical dilation before first-trimester surgical abortion (<14 weeks' gestation). SFP Guideline 20071

First-trimester surgical abortion is a common, safe procedure with a major complication rate of less than 1%. Cervical dilation before suction aspiration is usually accomplished using tapered mechanical dilators. Risk factors for major complications in the first trimester are increasing gestational age and provider inexperience. Use of laminaria for cervical priming reduces the risk of cervical laceration and, to a lesser extent, uterine perforation. While pharmacological priming agents may potentially have the same effects, no published studies to date have been large enough to assess these outcomes. Given an experienced provider, the risk of these injuries during suction aspiration is very small. Cervical priming can be achieved with osmotic dilators or pharmacological agents. The advantages of osmotic dilators such as laminaria, Dilapan-S and Lamicel are their ability to produce wide cervical dilation, and for the synthetic types, their advantages include predictable effects and rapid onset of action. A disadvantage of osmotic dilators is that they require a speculum examination and a trained clinician to perform the insertion. When cervical priming is performed, misoprostol is the prostaglandin analogue most commonly used worldwide. Compared to laminaria, vaginal misoprostol requires a shorter period of time to achieve the same dilatation, is associated with less discomfort and is preferred by women. The sublingual route appears as effective as vaginal administration and requires less time for priming (2 h), but it is associated with more side effects. Oral administration can produce equivalent dilation to vaginal or sublingual administration, but higher doses and longer treatment periods (8 to 12 h) are required. Buccal administration of misoprostol appears to have a pharmacokinetic and physiologic profile similar to vaginal administration; however, there are no published studies of buccal misoprostol prior to first-trimester suction abortion. While extensive data demonstrate that a variety of agents are safe and effective at causing cervical softening and dilation preoperatively, there are not enough data to conclude that routine cervical priming is necessary to reduce complications of first-trimester surgical abortion. Cervical priming increases preoperative cervical dilation, making the procedure easier and quicker for the physician. However, in order to preoperatively dilate the cervix, the woman must receive the agent at least 3 to 4 h prior to her procedure. Besides the additional waiting, the woman might experience bleeding and cramping prior to the procedure. There are insufficient data evaluating how cervical priming affects women's quality of life in relation to abortion. Based on existing evidence, the Society of Family Planning does not recommend routine cervical priming for suction aspiration procedures. The Society of Family Planning further recommends that providers consider cervical priming only for women who may be at increased risk of complications from cervical dilation, including those late in the first trimester, adolescents and women in whom cervical dilation is expected to be difficult due to either patient factors or provider experience.