Pretreatment with mifepristone (RU 486) reduces interval between prostaglandin administration and expulsion in second trimester abortion

An analysis of misoprostol effectiveness in second trimester pregnancy terminations

Background/Aim: Misoprostol is frequently used as a single agent in pregnancy terminations. However, it increases the risk of uterine rupture in patients who have had previous uterine surgery and terminations due to stillbirths. Therefore, it is used with concern by clinicians. The aim of this study was to evaluate the clinical features of the groups that responded and did not respond to termination treatment with misoprostol in a tertiary center and to investigate its efficacy and safety. Methods: The study design was comprised of a retrospective cohort study. A total of 114 second trimester pregnancies (between 13-24 weeks gestational age) were included in the study. These pregnancies were indicated for termination based on the prenatal diagnosis unit for fetal or maternal causes. According to the International Federation of Gynecology and Obstetrics (FIGO) directions, misoprostol was applied in the following dosages: for 13-17 weeks gestational ages, one tablet per 6 hours; for 18-26 gestational ages, ½ tablet per 6 hours; and for other indications 2 tablets per 3 hours were administered. If the patient had had a previous cesarean operation, all doses were halved. After the first 24 hours, the percentage and demographics results, such as age, body mass index (BMI), gravida, number of cesareans, number of curettages, cervical lengths, BISHOP scores, gestational age, amniotic fluid index, and fetal cardiac beat of the patients with miscarriage, were recorded. Results: The number of cases resulting in miscarriage within 24 hours were 84 (73.7%) and within 48 hours were 14 (12.2%). The total of misoprostol doses used were 8 tablets of 200 mg, mean time until the complete abortion was 17 hours. Sixteen patients required additional treatment, of whom four required Foley catheterization, five required D&E, seven required resting, and no one required a hysterectomy. Uterine rupture occurred in two patients who needed laparotomic surgery. The maternal age (P=0.340), BMI (P=0.790), gravida (P=0.270), previous cesarean history (P=0.390), previous curettage number (P=0.520), cervical length (P=0.380), Bishop score (P=0.190), gestational age (P=0.072), amniotic fluid index (P=0.470) and presence of fetal cardiac beat (P=0.350) were similar between groups Conclusion: Our results indicated that misoprostol is a safe, useful, and effective treatment option for second trimester medical terminations. Caution should be exercised in its use in patients with a history of uterine surgery.

Does feticide shorten termination duration in second trimester pregnancy terminations?

Backround

A retrospective (case-controlled) study was conducted with the aim of identifying the effect of the use of misoprostol on termination time in patients who did and did not undergo feticide procedures in second trimester pregnancy terminations.

Methods

The sampling of the study consisted of 144 pregnant women who were diagnosed as having major fetal anomalies incompatible with life, and were recommended for termination of pregnancy. The investigation showed that feticide procedures were performed for 99 women, and feticide procedures were not performed for 45 women. Misoprostol protocol was administered for 48 hours in the termination period; whether the feticide procedure directly affected the termination duration in patients who did and did not undergo feticide was evaluated.

Results

Abortion/birth was achieved in 103 (71.5%) women during the first 48 hours. There was no significant difference between the termination duration of the misoprostol protocol among the women who did and did not undergo feticide. There was no significant difference between the termination durations and fetal biometric measurements (BPD, HC) except head diameters (p=0.020 and p=0.015).

Conclusions

The misoprostol protocol is shown to be effective and safe for the termination of pregnancies during the second trimester. Feticide has no affect on the duration of termination.

Effects of a prolonged, 72 hours, interval between mifepristone and gemeprost in second trimester termination of pregnancy: a retrospective analysis

OBJECTIVE

To evaluate if the 72 hours interval between mifepristone and gemeprost has a similar efficacy compared to the 48 hours interval for second trimester termination of pregnancy

STUDY DESIGN

Two-hundred and fifteen consecutive pregnant women, admitted to our hospital, for second trimester TOP, were included in this retrospective analysis. Standard protocol was followed for all patients. On the first day of the procedure oral mifepristone 200 mg was administered. After 72 (group A, n = 78) or 48 hours (group B, n = 113) women were admitted for administration of gemeprost 1 mg pessary as per protocol. The induction to abortion time was defined as the interval between the insertion of the first gemeprost pessary and the expulsion of the fetus.

RESULTS

There are no significant differences in the number of pessaries in the two groups. The induction to abortion interval was longer in group A than in group B. Twenty-one women required surgical evacuation of the uterus for retained placenta or incomplete abortion without difference between groups.

CONCLUSION

A 48-hours interval between mifepristone and gemeprost leads to better results than a 72-hours interval, with a shorter abortion length and represents the elective method for second trimester TOP.

Mifepristone followed by misoprostol or oxytocin for second-trimester abortion: a randomized controlled trial

OBJECTIVE

To compare two methods for induction of second-trimester abortion after priming the cervix with mifepristone.

METHODS

This was a randomized prospective trial carried out between January 2009 and February 2012. The participants were healthy women between 14 and 24 weeks of gestation with missed miscarriage or need for termination of pregnancy. All participants received oral 200 mg mifepristone and, after 36 hours, after randomization, were given either a high-concentration oxytocin drip (maximal dose of 150 milli-international units/min) for up to 36 hours or 800 micrograms misoprostol vaginally followed by 400 micrograms oral misoprostol every 3 hours with a maximum of four oral doses. If expulsion of the fetus was not achieved, another 200 mg mifepristone was administered and another course of misoprostol was delivered as described previously. The primary outcome measure was success expulsion of the fetus in 36 hours since starting on uterotonic agent. Secondary outcomes included time until expulsion of the fetus and rate of adverse outcomes.

RESULTS

Success rates in the mifepristone-misoprostol and mifepristone-oxytocin arms were 100% (70/70 patients) and 95.8% (69/72), respectively (relative risk 1.043, 95% confidence interval 0.99-1.10, P=.13). Time until fetal expulsion was shorter in the mifepristone-misoprostol arm (7.0 ± 4.9 hours compared with 11.3 ± 7.4 hours, P<.001). However, the rate of adverse effects in the misoprostol group was higher than in the oxytocin group. Factors associated with a shorter time until expulsion were missed miscarriage compared with therapeutic abortion, increased ultrasonographic gestational age, and increased parity.

CONCLUSION

The two regimens studied had comparable efficacy for induction of second-trimester abortion; however, the mifepristone-oxytocin regimen has a longer time until expulsion but with fewer side effects.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00784797.

LEVEL OF EVIDENCE

: I.

Misoprostol vs mifepristone and misoprostol in second trimester termination of pregnancy

OBJECTIVE

The present study was conducted with the aim to assess and comparatively evaluate the safety and efficacy of misoprostol alone and mifepristone with misoprostol for second trimester termination of pregnancy.

METHODS AND MATERIALS

The study was conducted on 200 selected cases, divided in two groups of 100 cases each. In the study group mifepristone was given 200 mg 12 h before intravaginal insertion of 600 μg of misoprostol followed by 400 μg every 3 h up to a maximum of 5 doses or until the abortion occurs, whichever occurs early. In the control group only misoprostol was inserted in the same dose regime. The results were analyzed.

RESULTS

The success rate in both regimens was 100%. Mean induction abortion interval from the insertion of the first misoprostol tablet was significantly shorter in the mifepristone pretreated group 6.72 ± 2.26 h as compared to 12.93 ± 3.4 h in the misoprostol alone group (P < 0.001). The mean blood loss was slightly higher in the control group. The mean dose of the misoprostol required was significantly less in the study group 1,186 ± 291.64 μg as against 1,736 ± 320.20 μg (P < 0.001). The side effects observed in both the groups were similar mainly nausea vomiting, fever, abdominal cramps.

CONCLUSION

Pretreatment with mifepristone 12 h before intravaginal misoprostol significantly improves the induction abortion interval.

Late termination of pregnancy and foetal reduction for foetal anomaly

Late termination of pregnancy is a relatively rare procedure accounting for approximately 1% of all registered terminations in England and Wales; however, with improving detection rates for foetal anomalies, this number is increasing. Surgical dilation and evacuation (D&E) appears to be a safe and cost-effective procedure as long as the clinical expertise exists to provide this service. Medical termination appears equally safe and is best undertaken with the combined use of mifepristone and misoprostol. Foeticide, when required, should be performed from 22 weeks' gestation using strong KCl administered either by cardiocentesis or by cordocentesis. All women should be offered a post-mortem and any other appropriate investigation to allow accurate counselling regarding future pregnancies. The issue of late selective foetal reduction for foetal abnormality is complicated by the need to balance the risks to the healthy co-twin of expectant management versus selective termination.

Optimization of third-stage management after second-trimester medical pregnancy termination

OBJECTIVE

Comparison of 3 regimens for third-stage management after second-trimester intravaginal misoprostol termination.

STUDY DESIGN

Prospective randomized trial. Three third-stage management strategies were compared: 10 units of intramuscular oxytocin (group 1), 600 microg oral misoprostol (group 2), or no additional medication (group 3) after fetal expulsion. Primary study outcome was the incidence of placental retention.

RESULTS

Two hundred fifty-one women were randomly assigned to the groups. There was a significant difference in placental retention rates: group 1, 8 of 83 (10%) vs group 2, 24 of 83 (29%) vs group 3, 26 of 85 (31%); P = .002. Blood loss was significantly lower in group 1, 100 mL (interquartile ranges, 50-200) vs group 2, 200 mL (interquartile ranges, 100-370) vs group 3, 200 mL (interquartile ranges, 100-375); P < .001. Requirement for blood transfusion: group 1, 1 of 83 (1%) vs group 2, 1 of 83 (1%) vs group 3, 5 of 85 (6%); P = .103.

CONCLUSION

Intramuscular oxytocin administered after fetal delivery after second-trimester medical termination significantly increases placental expulsion rates and decreases short-term postpartum blood loss.

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.

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.

Clinical applications of mifepristone

Mifepristone is a progesterone antagonist that has been studied for a number of clinical applications. It is a well-known abortifacient that is effective for both first- and second-trimester medical abortion when used with a prostaglandin analog. It is also an effective cervical priming agent that can be used to soften the cervix before surgical evacuation. Its clinical efficacy as an emergency contraception has been proven. Other applications including treatment for fibroids, endometriosis and various cancers have been explored. However, its association with abortion limits the applications of mifepristone in many of these areas.

Mifepristone- and misoprostol-induced mid-trimester termination of pregnancy: A review of 272 cases

BACKGROUND

Mifepristone became available in New Zealand in 2001, and was first used for second trimester terminations at the Level J Unit, Wellington Hospital. The protocol is based on that published by Ashok et al. in Aberdeen.

AIMS

To describe the use of mifepristone prior to misoprostol induction of labour for mid-trimester termination and to compare outcomes with the published data.

METHODS

A retrospective audit of prospectively collected notes for 272 women presenting for mid-trimester termination of pregnancy in a hospital termination clinic. Data collection included age, ethnicity, previous pregnancies, gestational age, induction-to-abortion interval, analgesia, and complications. Data were entered into an Access database and imported into Excel and Epi Info for the computation of descriptive statistics.

RESULTS

Data on completed abortion were available for 271 women (one chose not to continue the abortion following mifepristone). The median time to abortion was 6 h, and mean number of doses of misoprostol was three. The proportion of women who aborted within 24 h was 95.9%. Immediate surgical evacuation of retained placenta was required in 22 women (8.1%). Heavy bleeding occurred in 22 women (8.1%), and seven required a transfusion (2.6%). The proportion of women who required parenteral narcotics was 78.2%.

CONCLUSIONS

Outcomes for women in the present review were comparable with those for previous publications using the same regimen, with the exception of a higher transfusion rate. Our experience supports the finding that the use of mifepristone as pretreatment to misoprostol results in a shorter induction-to-delivery interval than the use of misoprostol alone as has been reported by other groups.

Mid-trimester induced abortion: a review

Mid-trimester abortion constitutes 10-15% of all induced abortion. The aim of this article is to provide a review of the current literature of mid-trimester methods of abortion with respect to efficacy, side effects and acceptability. There have been continuing efforts to improve the abortion technology in terms of effectiveness, technical ease of performance, acceptability and reduction of side effects and complications. During the last decade, medical methods for mid-trimester induced abortion have shown a considerable development and have become safe and more accessible. The combination of mifepristone and misoprostol is now an established and highly effective method for termination of pregnancy (TOP). Advantages and disadvantages of medical versus surgical methods are discussed. Randomized studies are lacking, and more studies on pain treatment and the safety of any method used in patients with a previous uterine scar are debated, and data are scarce. Pain management in abortion requires special attention. This review highlights the need for randomized studies to set guidelines for mid-trimester abortion methods in terms of safety and acceptability as well as for better analgesic regimens.

Review of medical abortion using mifepristone in combination with a prostaglandin analogue

Induced abortion is still a major health problem in the world and the most frequently performed intervention in obstetrics and gynecology with an estimated total of 46 million worldwide each year. Medical abortion with mifepristone and prostaglandin was first introduced in 1988 and is now approved in 31 countries. This combination of drugs has recently been included in the List of Essential Medicines by the World Health Organisation. The present review summarizes the development, physiology and the development of the currently used regimens.

Induction of second trimester abortion (12–20 weeks) with mifepristone and misoprostol: a review of 386 consecutive cases

DESIGN

A retrospective analysis of 386 women who underwent termination of pregnancy between 12 and 24 weeks' gestation.

METHODS

Each woman received 200 mg mifepristone orally followed by vaginal misoprostol 800 microg 36 to 48 h later. Three hours after the initial misoprostol administration, 400-microg doses of vaginal misoprostol were administered every 3 h, to a maximum of four doses in 24 h. If abortion failed, 200 mg mifepristone is given again 3 h after the last misoprostol dose, followed by 12 h of rest before vaginal misoprostol administration is repeated as per previous course of treatment.

RESULTS

Overall, 97.9% and 99.5% of the women aborted within 24 and 36 h, respectively. The median induction-to-abortion interval was 6.7 h (range: 1.4-73.8 h), and nulliparous women took significantly longer time to abort (6.0 h in multiparous women compared to 7.6 h in nulliparous women; p<.0001). One woman failed to abort within 48 h. Surgical evacuation of the uterus was performed in 5% of women for incomplete abortion or retained placenta. Multiparous women were less likely to need analgesic administration for pain relief, and to experience vomiting and diarrhea, than nulliparous women.

CONCLUSION

The combination of 200 mg mifepristone and vaginally administered misoprostol is a safe, effective and noninvasive regimen for termination of pregnancy between 12 and 20 weeks.

A randomized comparison of oral mifepristone to intravenous oxytocin for labor induction in women with prelabor rupture of membranes beyond 36 weeks' gestation

OBJECTIVE

This study was undertaken to compare the use of oral mifepristone with intravenous oxytocin for labor induction in women with prelabor rupture of membranes (PROM) at 36 weeks' or greater gestational age.

STUDY DESIGN

Sixty-five women with spontaneous PROM were randomly assigned to receive orally administered mifepristone or oxytocin infusion. Two hundred milligrams of mifepristone was administered, and subjects were observed for 18 hours, or intravenous oxytocin was administered.

RESULTS

Thirty-three women received mifepristone and 32 received oxytocin. The average interval from start of induction to delivery was 1194.1 +/- 568.7 minutes for mifepristone-treated subjects and 770.8 +/- 519.9 minutes for oxytocin-treated subjects ( P = .001, log-transformed data). Of 33 mifepristone-treated subjects and 32 oxytocin-treated subjects, 25 (78.1%) and 17 (51.5%), respectively, achieved successful induction (defined as vaginal delivery within 24 hours) (relative risk [RR] 0.66, 95% CI 0.45-0.96, P = .01). There was more fetal distress in the mifepristone-treated group (9 vs 2, RR 4.36, 95% CI 1.02-18.66, P = .02), and a trend toward more cesarean births (7 vs 3, RR 2.26, 95% CI 0.64-7.99, P = .19). Eleven infants of mifepristone-treated women (33.3%) and 3 infants of oxytocin-treated women (9.4%) were admitted to the neonatal intensive care unit (RR 3.56, 95% CI 1.09-11.58, P = .02).

CONCLUSION

Oral mifepristone administration 18 hours before oxytocin infusion did not improve labor stimulation in women with PROM near term, and was associated with more adverse fetal outcomes.

Medical management for termination of second and third trimester pregnancies: a comparison of strategies

OBJECTIVE

Misoprostol and sulprostone are prostaglandins that can be used for the termination of second and third trimester pregnancy. The aim of the present study was to compare the effectiveness of both agents for the termination of second and third trimester pregnancy in cases of congenital or genetic abnormalities, and for the induction of labour in cases of intra-uterine foetal death.

STUDY DESIGN

We collected data from all women who had been treated with misoprostol in the second or third trimester of pregnancy between January 2001 and July 2002 in cases of congenital or genetic abnormalities, and for the induction of labour in cases of intra-uterine foetal death. In cases where the foetus was alive, misoprostol was usually (77%) combined with mifepristone. Women were matched to women who had been treated with sulprostone for termination of second and third trimester pregnancy before 2001. We matched for hospital, previous vaginal delivery, intra-uterine death and duration of pregnancy. The primary outcome measure was time to delivery.

RESULTS

Since the treatment effect was different in patients in whom labour was induced for intra-uterine death and patients in whom labour was induced while the foetus was alive, the analysis was stratified for this parameter. In 94 patients with intra-uterine death, there was no significant difference in time to delivery, blood loss, operative removal of the placenta and need for pain relief between misoprostol and sulprostone. In vital pregnancy (n = 96), time to delivery was significantly shorter in the misoprostol group. The relative risk for haemorrhage exceeding 1000 ml in this group was 0.40 (95% confidence interval, CI, 0.13-1.2). We observed no significant differences with respect to operative removal of the placenta or need for pain relief.

CONCLUSION

In cases of intra-uterine death, the effectiveness of misoprostol for termination of pregnancy is comparable to that of sulprostone. In vital pregnancy, combination of mifepristone and misoprostol is more effective than sulprostone alone.

Induction of labor with 50 and 100μg of misoprostol: comparison of maternal and fetal outcomes

OBJECTIVE

The aim of this randomized controlled study was to compare the efficacy and the safety of different regimens of misoprostol for labor induction. MATERIALS AND METHODS Eligible women received intravaginal 100 microg, every 6 h or 50 microg every 4 h. Treatment continued until: (1) dilatation >3 cm; (2) rupture of membranes (artificial); (3) signs of uterine hyperstimulation; (4) adequate contraction pattern (three contraction/10 min). Managing clinician might use oxytocin during labor. Cesarean section rate was the main outcome that was considered variably. Other outcome measures were neonatal outcome (Apgar scores, meconium staining, and umbilical artery pH) and induction to delivery interval.

RESULTS

A total number of 72 women received either misoprostol 100 microg (n=37), or 50 microg (n=35) randomly. The two groups had similar mean Bishops scores at induction (4.10+/-2.4 versus 4.2+/-2.1; P=0.85), rates of nulliparity, use of epidural anesthesia, and oxytocin augmentation. In two groups the number of doses of misoprostol used was similar (1.6+/-0.5 versus 1.7+/-0.3)

CONCLUSION

There was not any difference between the two groups in the mean+/-S.D. time to delivery (h) and cesarean rate. Likewise, there was not a significance between two groups in the rates of 5 min Apgar score, and of meconium passage.

Midtrimester medical termination of pregnancy: a review of 1002 consecutive cases

We assessed the effectiveness, safety and factors that affected the outcome of midtrimester medical termination of pregnancy at 13-21 weeks gestation. Of the 1002 women, 3 took mifepristone and decided to continue with the pregnancy, with 999 women being compliant with the regimen. Of these, 2 women aborted prior to administration of misoprostol and 970 (97.1%) aborted successfully within five doses of misoprostol. Surgical intervention was necessary to complete the abortion process in 81 (8.1%) women. Women with no previous pregnancy (p = 0.02), no previous live birth (p = 0.0001) and gestations 17-21 weeks (p = 0.001) required more prostaglandin. Younger women (p = 0.0001) and women with a previous live birth (p = 0.001) were more likely to have a successful abortion. The induction abortion interval was significantly longer with increasing gestation [95% confidence interval (CI) difference in means: -2.52 to -0.89, p = 0.0001], increasing age (p = 0.0001) and no previous live birth (95% CI difference in means: -0.25 to -1.01, p = 0.0001). Surgical intervention was more likely to be required with increasing age (p = 0.008). Mifepristone in combination with misoprostol is a safe and effective regimen for midtrimester medical abortion with younger women and those with a previous live birth more likely to have a successful abortion.

Pharmacological properties of mifepristone: toxicology and safety in animal and human studies

Roussel Uclaf in partnership with the INSERM unit of Prof. E.E. Baulieu first discovered mifepristone (RU486) as part of a large research program on steroidal compounds with antihormone properties. Exhibiting a strong affinity to the progesterone and the glucocorticoid receptors, mifepristone exerted competitive antagonism to these hormones both in in vitro and in animal experiments. Due to its antiprogesterone activity, it was proposed that mifepristone be used for the termination of early human pregnancy. Mifepristone, at a dose of 600 mg initially used alone, was then used with a subsequent low dose of prostaglandin that led to a success rate of 95% as a medical method for early termination of pregnancy (TOP). Its use was extended to other indications, such as cervical dilatation prior to surgical TOP in the first trimester, therapeutic TOP for medical reasons beyond the first trimester, and for labor induction in case of fetal death in utero. The efficacy and safety of this treatment has been confirmed based on its use for over a decade, with close adherence to the approved recommendations. This paper describes the safety studies conducted in animals as well as the safety follow-up and side effects reported with use of the compound in various indications either approved or unapproved. The rationale for warnings and contraindications for use of the product are also explained. At lower doses, the molecule has proven promising for contraceptive purposes with few reported side effects. However, development of the product for this indication would require long-term studies. Although political and philosophical obstacles have delayed research, the use of mifepristone for other potential indications in gynecology or oncology should be investigated.

A randomised study of misoprostol and gemeprost in combination with mifepristone for induction of abortion in the second trimester of pregnancy

OBJECTIVE

To compare the effectiveness of gemeprost and misoprostol as prostaglandins used in combination with mifepristone for induction of mid-trimester termination.

DESIGN

Randomised trial.

SETTING

Scottish teaching hospital.

SAMPLE

One hundred women undergoing abortion between 12 and 20 weeks.

METHODS

Each woman received 200 mg mifepristone and 36-48 hours later either 1 mg gemeprost vaginal pessary every 6 hours for 18 hours or 4 x 200 microg misoprostol tablets vaginally followed by 2 x 200 microg misoprostol tablets orally every 3 hours for 12 hours. Success was defined as the percentage of women aborted within 24 hours of the first administration of prostaglandin.

MAIN OUTCOME MEASURES

Prostaglandin-abortion interval and side effects.

RESULTS

There were no significant differences in median prostaglandin-abortion interval between gemeprost (6.6 hours 95% CI 6.0-10.7) and misoprostol (6.1 hours 95% CI 5.5-7.5) (P = 0.22). The cumulative abortion rates at 24 hours (96% vs 94%, respectively), the surgical evacuation rates (12% and 10%) and the incidence of vomiting, diarrhoea and pain were similar.

CONCLUSION

Two hundred milligrammes of mifepristone followed 36-48 hours later by either vaginal gemeprost or misoprostol is a highly effective way of inducing abortion in the second trimester of pregnancy.

Role of progesterone antagonists and new selective progesterone receptor modulators in reproductive health

Given the importance of progesterone in female reproductive health, it was inevitable that analogues of this molecule would be developed to treat a variety of gynecologic maladies. Such medications, termed progesterone antagonists, act to counteract the effect of progesterone. A newer class of molecules, the selective progesterone receptor modulators (SPRMs), have both agonist and antagonist activities depending upon the site of action. These compounds have been studied for their effect on endometrial growth, endometrial vascular development, the hypothalmic-pituitary-ovarian axis and cervical integrity. Such research has led to a number of potential clinical applications. Progesterone antagonists are well established in their use for termination of pregnancy, although SPRMs seem to have a diminished capacity for induction of abortion. Similarly, antagonists work well to soften and dilate the cervix before surgery, but such efficacy by SPRMs is unlikely. Other applications for progesterone antagonists include induction of labor, the treatment of endometriosis, fibroids and contraception; SPRMs also may prove useful in the treatment of endometriosis and fibroids, as well as for postmenopausal hormone replacement therapy and the treatment of dysfunctional uterine bleeding. Finally, these compounds may aid investigators in unraveling many of the nuances of the role of progesterone in reproductive function.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to describe the receptor action and selective modulation of progesterone, explain the effects of progesterone receptor modulators, and list the potential clinical applications of progesterone antagonists and selective progesterone receptor modulators.

Second trimester medical abortion with mifepristone and gemeprost: a review of 956 cases

The treatment outcomes of 956 women undergoing second trimester termination of pregnancy with mifepristone and gemeprost were studied. The median gestational age was 16 weeks (range: 12-24 weeks). All women were treated with 200 mg mifepristone orally, followed 36 h later with 1 mg vaginal gemeprost administered every 6 h to a maximum of 4 doses in the first 24 h. A second course of 1 mg vaginal gemeprost was given 3-hourly in the next 12 h, if abortion had not occurred. Overall, 96.4% and 98.8% of the women aborted within 24 and 36 h, respectively. The median induction-to-abortion interval was 7.8 h (range: 0.5-109.9 h). The induction-abortion interval was longer in nulliparous women and women with a gestation age 17 weeks or above. Surgical evacuation of the uterus was performed in 11.5% of women for incomplete abortion or retained placenta. More multiparous women (16.7%) required surgical evacuation of uterus than did nulliparous women (7.3%; p <0.001). Ten (0.1%) women failed to abort with gemeprost and required other methods for abortion. In conclusion, a combination of mifepristone and gemeprost is a safe, effective, and noninvasive method of medical abortion for second trimester pregnancy.

The effects of mifepristone on uterine sensitivity to oxytocin and on fetal heart rate patterns

OBJECTIVE

To compare the incidences of tachysystole, hypertonia and fetal heart rate (FHR) abnormalities in women treated by mifepristone plus prostaglandins (PGs), mifepristone alone or PGs alone for an unfavourable cervix.

STUDY DESIGN

In this retrospective study, all women between 37 and 42 weeks were eligible for the study if they had undergone cervical ripening prior to labour induction. In group 1, the women were treated with mifepristone plus PGs (n=103). Group 2 women were treated with mifepristone alone (n=96) and group 3 women with PGs alone (n=100). Incidences of tachysystole, hypertonia and FHR abnormalities were compared.

RESULTS

During induction of labour, tachysystole and hypertonia occurred more frequently in women treated with mifepristone. Severe bradycardia and recurrent late decelerations were more frequent after the initiation of oxytocin in groups 1 and 2 than in group 3.

CONCLUSIONS

In this study, mifepristone increased the incidences of tachysystole, hypertonia and FHR abnormality.

Nonsurgical mid-trimester termination of pregnancy: a review of 500 consecutive cases

OBJECTIVE

To assess the effectiveness of a regimen comprising mifepristone followed by a combination of the vaginal and oral administration of misoprostol for mid-trimester medical termination of pregnancy.

DESIGN

Retrospective analysis of prospectively collected data in women undergoing mid-trimester medical termination of pregnancy.

SETTING

Aberdeen Royal Infirmary, Scotland.

SAMPLE

A consecutive series of 500 women with pregnancies of 13-21 weeks of amenorrhea undergoing legally induced abortion in one Scottish NHS hospital.

METHODS

Each woman received a single oral dose of mifepristone 200 mg and 36-48 h later vaginal misoprostol 800 microg. Three hours following the first dose of misoprostol, 400 microg doses were administered orally at three hourly intervals, to a maximum of four doses. Success was defined as abortion occurring with five doses of prostaglandin, or within 15 h of administration of the first dose of prostaglandin.

RESULTS

Ninety-seven percent aborted successfully. The median dose of misoprostol required was 1200 microg and the median induction-to-abortion interval after first prostaglandin administration was 6.5 h. The median number of doses of misoprostol required to induce abortion, and the induction-to-abortion interval, was statistically significantly higher among women at gestations 17-21 weeks than among those at 13-16 weeks (P = 0.0001). A total of 9.4% required surgical evacuation of the uterus under general anaesthesia and 66.4% of the women were managed as day cases.

CONCLUSIONS

The combination of oral mifepristone 200 mg followed by vaginally and orally administered misoprostol provides a noninvasive and effective regimen for second trimester termination of pregnancy.

Second trimester abortion using intravaginal misoprostol

OBJECTIVE

To find the effective dose of intravaginal misoprostol to induce second trimester abortion.

METHODS

Intravaginal misoprostol in 200-microg, 400-microg and 600-microg doses were applied at 12-h intervals in 150 consecutive pregnancies.

RESULTS

The 48-h successful abortion rate was 70.6%, 82% and 96%, respectively, and these rates were unaffected by parity. The mean induction to abortion interval was 45.0 +/- 41.5, 33.4 +/- 34.9 and 22.3 +/- 14.3 h, respectively. The mean dose of misoprostol required to induce abortion was 416.7 microg, 772.8 microg and 1296 microg. The rate of nausea and vomiting was 3.9%, 12% and 20%. The diarrhea occurrence rate was 0%, 6% and 22% with temperature elevation 0%, 2% and 28%, respectively. The rate of incomplete abortion was 35.3%, 28% and 22%, respectively.

CONCLUSION

The 600-microg dose is more effective as an abortifacient agent for second trimester abortion in terms of 48-h success rate and the rate of incomplete abortion but with more side effects. However, the side effects were mild and did not warrant any specific treatment.

Effects of nomegestrol acetate on spontaneous and sulprostone-induced uterine contractions in pregnant cynomolgus monkeys monitored by telemetry

OBJECTIVE

Our purpose was to study the effects of the progestomimetic compound nomegestrol acetate on spontaneous and sulprostone-induced uterine contractility in pregnant cynomolgus monkeys.

STUDY DESIGN

Intrauterine pressure was continuously monitored with use of an implanted intraamniotic catheter and a telemetric pressure transmitter from day 115 to 135 of gestation (term = 165 days). After surgery the animals received either nomegestrol acetate (5 mg per day orally, n = 3) or vehicle only (controls, n = 3). The intramuscular prostaglandin E2 analog sulprostone (25 micrograms) was administered as a single injection 10 days after amniotic catheter implantation. Spontaneous and sulprostone-induced uterine contractions were compared between nomegestrol acetate- and vehicle-treated animals.

RESULTS

The frequency of spontaneous uterine contractions in control animals demonstrated a 24-hour pattern with a minimum at 12 hours and a maximum at 0 hours. The frequency of spontaneous contractions did not differ between nomegestrol acetate- and vehicle-treated animals. Sulprostone induced an increase in both the frequency and amplitude of contractions, reaching a maximum 12 hours after injection and fading out after 24 hours in vehicle-treated animals. In animals receiving nomegestrol acetate, the frequency of contractions increased moderately and transiently for a total duration of 6 hours only and returned to control levels thereafter.

CONCLUSION

Nomegestrol acetate significantly decreases the contractile response of the pregnant uterus induced by the prostaglandin E2 analog sulprostone.

Mifepristone (RU486): a review

OBJECTIVE

To review the literature concerning the mechanism of action and pharmacodynamics of mifepristone (RU486), potential new uses of RU486, and its current use not only as an abortifacient but also as therapy for endometriosis, leiomyoma, breast cancer, and meningioma.

DATA IDENTIFICATION AND SELECTION

Studies that relate to RU486 were identified through a MEDLINE search.

CONCLUSION(S)

RU486 is an 11 beta-dimethyl-amino-phenyl derivative of norethindrone with a high affinity for P and glucocorticoid receptors. The receptor binding is not followed by transcription of P-dependent genes. Mifepristone effectively blocks P receptors in the placenta, resulting in the termination of pregnancy. In addition, it has been used in the treatment of leiomyomata, endometriosis, advanced breast cancer, and meningioma. It is a powerful tool to study the molecular action of P and in the future may be used as an estrogen-free contraceptive.

Oral mifepristone 600 mg and vaginal gemeprost for mid-trimester induction of abortion. An open multicenter study. UK Multicenter Study Group

This open multicenter study was performed in 20 hospital gynecological units in the UK. The effects of 600 mg oral mifepristone as pretreatment to vaginal prostaglandin induction of second trimester abortion was studied in 267 women. The primary efficacy variable was the abortion induction interval, defined as the time taken to expel the fetus from the time of administration of the first prostaglandin pessary. Induction was commenced 36 to 48 hours following mifepristone intake. The mean abortion induction interval was 7 h. A total of 81.9% of women aborted within 12 h. There was a significant relationship between abortion induction interval and age of gestation, and a significant inverse relationship between abortion induction interval and parity. Vomiting, pelvic pain, and nausea were the most frequently reported adverse events. Two patients required transfusion and one patient with a uterine scar from a previous cesarean section suffered a ruptured uterus and hysterotomy.

Termination of 2nd and 3rd trimester pregnancies with mifepristone and misoprostol

OBJECTIVE

The purpose of this study was to evaluate our use of the association of mifepristone and misoprostol for terminating second and third trimester pregnancies.

STUDY DESIGN

One hundred and six patients undergoing termination of pregnancy between January 1993 and June 1995 in our center were studied. Each patient received 600 mg of mifepristone followed 24 h later by 400 microgrammes of misoprostol every 6 h.

RESULTS

The average interval from the first administration of misoprostol to expulsion was 12.5 +/- 7.5 h (interval markedly decreased to 9.6 +/- 6.3 h in cases of intrauterine fetal death).

CONCLUSION

The efficacy of the association of mifepristone and misoprostol is comparable with that of current regimens with grealer ease of utilization and at a much lower cost.

A randomised study of two doses of gemeprost in combination with mifepristone for induction of abortion in the second trimester of pregnancy

Two regimens of the prostaglandin E1 analogue, gemeprost, in combination with mifepristone were compared in a randomised trial for termination of pregnancy between 12-19 weeks. Thirty-six hours after treatment with 200 mg mifepristone, women were allocated at random to receive either 4 x 1 mg (Group I) or 4 x 0.5 mg (Group II) gemeprost by vaginal pessary every 6 hours (n = 50 in each group). If abortion had not occurred after 24 h, 5 x 1 mg of gemeprost was administered every 3 h to both groups of women. Although the median abortion interval was slightly shorter in the 1 mg group (7.8 h vs. 8.4 h, p = 0.5), the cumulative abortion rates at 24 h were similar (98% vs. 96%). Women in Group I required significantly more gemeprost to induce abortion than Group II (p < 0.0001). Parous women in both groups required significantly less of the prostaglandin to induce abortion. In Group II, the median abortion interval was significantly longer in primigravidae than multigravidae (9.5 h vs. 6.1 h; p < 0.02). There were no significant differences between the groups in the incidence of vomiting, diarrhoea or the request for analgesia. The results suggest that in parous women, the dose of gemeprost can be reduced to 0.5 mg every 6 h within the first 24 h without loss of clinical efficacy.

Termination of second trimester pregnancy with gemeprost and misoprostol: a randomized double-blind placebo-controlled trial

A prospective randomized double-blind placebo-controlled trial was conducted in 70 subjects to determine whether pre-treatment with misoprostol could facilitate termination of second trimester pregnancy by gemeprost. The women received either 400 micrograms oral misoprostol or placebo tablets 12 hours before the administration of vaginal pessary of gemeprost 1 mg every 3 hours. There were no significant differences in induction-abortion interval and the amount of gemeprost required between the misoprostol and the placebo group. There was no significant difference in the incidence of side effects or analgesic requirement between the two groups. We conclude that oral misoprostol is not useful in facilitating termination of second trimester pregnancy by gemeprost.

A comparison of 600 and 200 mg mifepristone prior to second trimester abortion with the prostaglandin misoprostol

OBJECTIVE

To compare the use of 600 and 200 mg mifepristone prior to second trimester termination of pregnancy with the prostaglandin misoprostol.

DESIGN

A randomised study.

SETTING

A Scottish teaching hospital.

PARTICIPANTS

Seventy women undergoing legal induced abortion between 13 and 20 weeks of gestation.

INTERVENTION

Administration of either 600 or 200 mg mifepristone 36 to 48 hours prior to prostaglandin.

MAIN OUTCOME MEASURE

Induction-abortion interval.

RESULTS

The geometric mean induction abortion interval was 6.9 (95% CI 5.8-8.4) h and 6.9 (95% CI 5.8-8.2) h in the 600 and 200 mg groups, respectively (no significant difference). The median dose of misoprostol was 1600 micrograms (three doses) in each group. Analgesic requirements and prostaglandin-related side effects were similar between groups. Overall, 11.4% of women required surgical evacuation of the uterus as a result of retained placenta.

CONCLUSIONS

The dose of mifepristone used in second trimester abortion can be reduced from 600 to 200 mg.