Late second-trimester abortions induced with mifepristone, misoprostol and oxytocin: a report of 428 consecutive cases

Prior Cesarean Birth and Risk of Uterine Rupture in Second-Trimester Medication Abortions Using Mifepristone and Misoprostol: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the risk difference of uterine rupture when using current mifepristone and misoprostol regimens for second-trimester abortion among individuals with prior cesarean birth compared with those without prior cesarean birth.

DATA SOURCES

We searched the terms second trimester, induction, mifepristone, and abortion in PubMed, EMBASE, POPLINE, ClinicalTrials.gov , and Cochrane Library from inception until December 2022.

METHODS OF STUDY SELECTION

We included randomized trials and observational studies including a mixed cohort, with and without uterine scar, of individuals at 14-28 weeks of gestation who used mifepristone and misoprostol to end a pregnancy or to manage a fetal death. We excluded case reports, narrative reviews, and studies not published in English. Two reviewers independently screened studies.

TABULATION, INTEGRATION, AND RESULTS

Absolute risks with binomial CIs were calculated from pooled data. Using R software, we estimated total risk difference by the Mantel-Haenszel random-effects method without continuity correction. For studies with zero events, a continuity correction of 0.5 was applied for individual risk differences and plotted graphically with forest plots. Statistical heterogeneity was assessed with Higgins I2 statistics. Funnel plot assessed for publication bias. Of 198 articles identified, 22 met the inclusion criteria: seven randomized trials (n=923) and 15 observational studies (n=6,195). Uterine rupture risk with prior cesarean birth was 1.1% (10/874) (95% CI 0.6-2.1) and without prior cesarean birth was 0.01% (2/6,244) (95% CI 0.0-0.12). The risk difference was 1.23% (95% CI 0.46-2.00, I2 =0%). Of the 12 reported uterine ruptures, three resulted in hysterectomy.

CONCLUSION

Uterine rupture with mifepristone and misoprostol use during second-trimester induction abortion is rare, with the risk increased to 1% in individuals with prior cesarean birth.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42022302626.

Society of Family Planning Clinical Recommendation: Medication abortion between 14 0/7 and 27 6/7 weeks of gestation: Jointly developed with the Society for Maternal-Fetal Medicine

The objective of this Clinical Recommendation is to review relevant literature and provide evidence-based recommendations for medication abortion between 14 0/7 and 27 6/7 weeks of gestation, with a focus on mifepristone-misoprostol and misoprostol-only regimens. We systematically reviewed PubMed articles published between 2008 and 2022 and reviewed reference lists of included articles to identify additional publications. See Search Strategy for more details. Several randomized trials of medication abortion between 14 0/7 and 27 6/7 weeks of gestation demonstrate that mifepristone 200 mg orally before misoprostol increases effectiveness (complete abortion at 24 or 48 hours) compared to misoprostol only. Studies continue to evaluate different doses, routes, and dosing intervals for misoprostol. If mifepristone is unavailable, several misoprostol regimens with individual doses of at least 200 mcg or more are effective. Adjunctive osmotic dilators are of limited benefit. It is important to individualize care, with consideration to reducing misoprostol dose in low-resource settings or at 24 0/7 weeks of gestation or later (or equivalent uterine size). Misoprostol in the setting of two or more previous cesarean sections is associated with increased risk of uterine rupture compared to one or none, but risk remains low. Most contraceptives can be started during or immediately following abortion. Appropriately trained and credentialed advanced practice clinicians can provide medication abortion between 14 0/7 and 27 6/7 weeks of gestation with appropriate backup within the confines of local regulations and licensure.

Society of Family Planning Clinical Recommendation: Medication abortion between 14 0/7 and 27 6/7 weeks of gestation: Jointly developed with the Society for Maternal-Fetal Medicine

The objective of this Clinical Recommendation is to review relevant literature and provide evidence-based recommendations for medication abortion between 14 0/7 and 27 6/7 weeks of gestation, with a focus on mifepristone-misoprostol and misoprostol-only regimens. We systematically reviewed PubMed articles published between 2008 and 2022 and reviewed reference lists of included articles to identify additional publications. See Search Strategy for more details. Several randomized trials of medication abortion between 14 0/7 and 27 6/7 weeks of gestation demonstrate that mifepristone 200 mg orally before misoprostol increases effectiveness (complete abortion at 24 or 48 hours) compared to misoprostol only. Studies continue to evaluate different doses, routes, and dosing intervals for misoprostol. If mifepristone is unavailable, several misoprostol regimens with individual doses of at least 200 mcg or more are effective. Adjunctive osmotic dilators are of limited benefit. It is important to individualize care, with consideration to reducing misoprostol dose in low-resource settings or at 24 0/7 weeks of gestation or later (or equivalent uterine size). Misoprostol in the setting of two or more previous cesarean sections is associated with increased risk of uterine rupture compared to one or none, but risk remains low. Most contraceptives can be started during or immediately following abortion. Appropriately trained and credentialed advanced practice clinicians can provide medication abortion between 14 0/7 and 27 6/7 weeks of gestation with appropriate backup within the confines of local regulations and licensure.

Maternal complications associated with second trimester medical abortion using mifepristone priming and subsequent misoprostol

OBJECTIVES

To assess the frequency of maternal adverse events associated with second trimester medical abortion using sequential mifepristone and misoprostol.

STUDY DESIGN

Retrospective analysis of medical abortions 13 to 28 weeks gestation using sequential mifepristone and misoprostol in a single center from January 2008 to December 2018. The main outcomes evaluated were the nature and incidence of adverse procedural events and the impact of gestation upon these outcomes.

RESULTS

During the study period, 1393 people underwent a medical abortion with sequential mifepristone and misoprostol. The median maternal age was 31 years (IQR 27-36 years) and 21.8% had at least one prior cesarean delivery. The median gestational age at abortion commencement was 19 weeks (IQR 17-21). The main adverse maternal events were complete or partial placental retention greater than 60 minutes triggering removal in the operating room (19%), maternal hemorrhage>1000 cc (4.3%), blood transfusion (1.7%), hospital readmission (1.4%), uterine rupture (0.29%) and hysterectomy (0.07%). There were significant reductions in placental retention rates with increasing gestational age (23.3% at 13-16 weeks gestation declining to 10.1% at>23 weeks gestation, p < 0.001).

CONCLUSIONS

Serious adverse maternal events associated with second trimester medical abortion with sequential mifepristone-misoprostol are uncommon.

IMPLICATIONS

Second trimester medical abortion with mifepristone and misoprostol is generally safe, however, on occasions serious complications may occur. All health care units providing a medical abortion service require the facilities and expertise to deal with these adverse events in a timely manner.

Mifepristone priming and subsequent misoprostol for second trimester medical abortion in women with previous caesarean delivery

AIMS

To assess clinical outcomes and complications in women with ≥1 prior caesarean delivery (CS) during mid-pregnancy medical abortion with misoprostol following mifepristone priming.

MATERIALS AND METHODS

Retrospective analysis of abortions at 13-28 weeks gestation using sequential mifepristone and misoprostol at a single centre from 1/2008-12/2018. Procedural outcomes were compared between cases with no prior CS, one prior and ≥2 prior CS.

RESULTS

There were 1399 consecutive women who underwent a medical abortion, with 304 (21.7%) having ≥1 prior lower segment CS (241 one, 49 two, 12 three, one four) and one a prior classical CS. Median gestation was 19 weeks (interquartile range (IQR) 17-21) among nulliparas, multiparas with no prior CS and multiparas with prior CS, P = 0.505. Compared with nulliparas (median procedural duration 10.8 h, IQR 7.5-16.5; adjusted hazards ratio (aHR) = 1.20 95%CI 1.04-1.40, P = 0.015), multiparas with prior CS had a shorter procedural duration (9.5 h, IQR 6.5-13.5) while multiparas with no CS had the shortest duration (7.0 h, IQR 5.0-9.8; aHR = 2.28 95%CI 2.01-2.58, P < 0.001). Complications were more frequent with prior CS: estimated blood loss (medians: 100 cc no CS vs 150 cc ≥1 CS, P = 0.002), blood loss >1000 cc (3.6% no CS vs 7.2% ≥1 CS; odds ratio (OR) = 2.11 95%CI 1.23-3.62, P = 0.007) and placental retention (17.3% no CS vs 25.3% ≥1 CS; adjusted OR = 1.44 95%CI 1.05-1.99, P = 0.024). Uterine rupture occurred in 4/304 women with ≥1 prior CS (1.3%).

CONCLUSIONS

Mifepristone-misoprostol abortion in women with prior CS is generally safe but associated with an increased risk of procedural complications. Lowering of the misoprostol dosage with prior CS may reduce uterine rupture, although this hypothesis requires ongoing research.

Effects of Prophylactic Oxytocin on Bleeding Outcomes in Women Undergoing Dilation and Evacuation: A Randomized Controlled Trial

OBJECTIVE

To estimate whether routine use of intravenous oxytocin decreases the frequency of interventions to control excess blood loss during dilation and evacuation (D&E).

METHODS

In this multisite, randomized, double-blind, placebo-controlled trial, women undergoing D&E at 18-24 weeks of gestation received 30 units of oxytocin in 500 mL of intravenous fluid or 500 mL of intravenous fluid alone initiated on speculum placement. The primary outcome was the frequency of interventions to control excess bleeding. A sample size of 75 patients per group was needed to detect a 15% decrease in intervention from 20% to 5% with 80% power and two-sided alpha 0.05. Secondary outcomes included measured blood loss, complications, procedure duration, postoperative pain, and patient satisfaction.

RESULTS

From November 2014 to February 2018, we screened 337 women and randomized 160 to receive prophylactic oxytocin (n=82) or placebo (n=78). Demographic characteristics were similar between groups. The frequency of interventions for bleeding, our primary outcome, was 7.3% in the oxytocin group vs 16.7% in the placebo group, difference of 9.4% (95% CI -21.0% to 1.9%). Interventions primarily included uterine massage and uterotonic administration. Among our secondary outcomes, median measured blood loss was lower in the oxytocin group at 152 (interquartile range 98-235) mL vs 317 (interquartile range 168-464) mL (95% CI 71.6-181.5). Frequency of hemorrhage, defined as blood loss of 500 mL or more and 1,000 mL or more, was lower in the oxytocin group at 3.7% vs 21.8%, difference of 18% (95% CI -29 to -6.9%) and 1.2% vs 10.3%, difference of 9.0% (95% CI -17 to -0.7%), respectively. Procedures were shorter in the oxytocin group at a median of 11.0 (interquartile range 8.0-14.0) vs 13.5 (interquartile range 10.0-19.0) minutes in the placebo group (95% CI 1.0-4.0). We found no differences in the frequency of nonhemorrhage complications, pain scores, or satisfaction scores between groups.

CONCLUSION

Prophylactic use of oxytocin during D&E at 18-24 weeks of gestation did not decrease the frequency of interventions to control bleeding. However, oxytocin did decrease blood loss and frequency of hemorrhage.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT02083809.

No. 360-Induced Abortion: Surgical Abortion and Second Trimester Medical Methods

OBJECTIVE

This guideline reviews evidence relating to the provision of surgical induced abortion (IA) and second trimester medical abortion, including pre- and post-procedural care.

INTENDED USERS

Gynaecologists, family physicians, nurses, midwives, residents, and other health care providers who currently or intend to provide and/or teach IAs.

TARGET POPULATION

Women with an unintended or abnormal first or second trimester pregnancy.

EVIDENCE

PubMed, Medline, and the Cochrane Database were searched using the key words: first-trimester surgical abortion, second-trimester surgical abortion, second-trimester medical abortion, dilation and evacuation, induction abortion, feticide, cervical preparation, cervical dilation, abortion complications. Results were restricted to English or French systematic reviews, randomized controlled trials, clinical trials, and observational studies published from 1979 to July 2017. National and international clinical practice guidelines were consulted for review. Grey literature was not searched.

VALUES

The quality of evidence in this document was rated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology framework. The summary of findings is available upon request.

BENEFITS, HARMS, AND/OR COSTS

IA is safe and effective. The benefits of IA outweigh the potential harms or costs. No new direct harms or costs identified with these guidelines.

Maternal outcomes in first and second trimester termination of pregnancy: which are the risk factors?

AIMS

To evaluate maternal complications of first trimester and second trimester termination of pregnancy (TOP) performed after first or second trimester positive prenatal diagnosis (PD).

RESULTS

We performed a retrospective study from January 2007 to December 2011, on 844 patients, who underwent a TOP after positive amniocentesis or chorionic villus sampling (CVS) for foetal aneuploidies, performed for maternal age ≥35 years of age, positive prenatal screening (PS) or for genetic reasons. Exclusions criteria were gestational age >22+0 weeks, twin pregnancy and co-existing maternal pathologies. We compared maternal complications of first trimester and second trimester TOP and we established which risk factors were correlated to higher maternal complications (haemorrhages, transfusion, repeated uterine curettage and infections). Maternal complications were significantly higher in second trimester TOP. Previous uterine surgery is a significant risk factor for maternal complications in second trimester TOP, but not in first trimester TOP. Six uterine ruptures and three hysterectomies occurred, all in multiparous women with second trimester TOP. All uterine ruptures occurred in women with previous caesarean sections.

CONCLUSIONS

First trimester TOP in women with risks factors for maternal complications guarantees better maternal outcomes and less health costs. Thus, in these women we should prefer a first trimester PS and PD.

Cervical ripening agents in the second trimester of pregnancy in women with a scarred uterus: a systematic review and metaanalysis of observational studies

OBJECTIVE

The aim of this systematic review and metaanalysis was to determine the efficacy and safety of cervical ripening agents in the second trimester of pregnancy in patients with previous cesarean delivery.

STUDY DESIGN

Data sources were PubMed, EMBASE, CINAHL, LILACS, Google Scholar, and clinicaltrials.gov (1983 through 2015). Eligibility criteria were cohort or cross-sectional studies that reported on efficacy and safety of cervical ripening agents in patients with previous cesarean delivery. Efficacy was determined based on the proportion of patients achieving vaginal delivery and vaginal delivery within 24 hours following administration of a cervical ripening agent. Safety was assessed by the risk of uterine rupture and complications such as retained placental products, blood transfusion requirement, and endometritis, when available, as secondary outcomes. Of the 176 studies identified, 38 met the inclusion criteria. Of these, 17 studies were descriptive and 21 studies compared the efficacy and safety of cervical ripening agents between patients with previous cesarean and those with no previous cesarean. From included studies, we abstracted data on cervical ripening agents and estimated the pooled risk differences and risk ratios with 95% confidence intervals. To account for between-study heterogeneity, we estimated risk ratios based on underlying random effects analyses. Publication bias was assessed via funnel plots and across-study heterogeneity was assessed based on the I(2) measure.

RESULTS

The most commonly used agent was PGE1. In descriptive studies, PGE1 was associated with a vaginal delivery rate of 96.8%, of which 76.3% occurred within 24 hours, uterine rupture in 0.8%, retained placenta in 10.8%, and endometritis in 3.9% in patients with ≥1 cesarean. In comparative studies, the use of PGE1, PGE2, and mechanical methods (laminaria and dilation and curettage) were equally efficacious in achieving vaginal delivery between patients with and without prior cesarean (risk ratio, 0.99, and 95% confidence interval, 0.98-1.00; risk ratio, 1.00, and 95% confidence interval, 0.98-1.02; and risk ratio, 1.00, and 95% confidence interval, 0.98-1.01; respectively). In patients with history of ≥1 cesarean the use of PGE1 was associated with higher risk of uterine rupture (risk ratio, 6.57; 95% confidence interval, 2.21-19.52) and retained placenta (risk ratio, 1.21; 95% confidence interval, 1.03-1.43) compared to women without a prior cesarean. However, the risk of uterine rupture among women with history of only 1 cesarean (0.47%) was not statistically significant (risk ratio, 2.36; 95% confidence interval, 0.39-14.32), whereas among those with history of ≥2 cesareans (2.5%) was increased as compared to those with no previous cesarean (0.08%) (risk ratio, 17.55; 95% confidence interval, 3.00-102.8). Funnel plots did not demonstrate any clear evidence of publication bias. Across-study heterogeneity ranged from 0-81%.

CONCLUSION

This systematic review and metaanalysis provides evidence that PGE1, PGE2, and mechanical methods are efficacious for achieving vaginal delivery in women with previous cesarean delivery. The use of prostaglandin PGE1 in the second trimester was not associated with significantly increased risk for uterine rupture among women with only 1 cesarean; however, this risk was substantially increased among women with ≥2 cesareans although the absolute risk appeared to be relatively small.

Influence of Mifepristone in Induction Time for Terminations in the Second and Third Trimester

Termination of pregnancy after the first trimester is generally carried out by medical induction. Question: The aim of this study is to investigate the effect of mifepristone before administration of the prostaglandin derivative on induction time. Material and Methods: We analysed 333 medically indicated terminations after the first trimester under the terms of § 218 a Para. 2 of the German Criminal Code, in which the prostaglandin derivatives misoprostol, gemeprost or dinoprostone were administered with or without pre-treatment with 600 mg of mifepristone. The time interval between the initial administration of prostaglandin and delivery was investigated. Using uni- and multivariate regression analysis, the effect of maternal age, body mass index, gravidity and parity, previous Caesarean sections, gestational age and the induction regimen on the induction time were analysed. Results: The average induction time was significantly shortened with mifepristone (15.1 ± 11.9 hours with mifepristone vs. 25.3 ± 24.2 hours without mifepristone [p < 0.001]). The combination of mifepristone and misoprostol was most frequently used and proved to be the most effective regimen, reducing the induction period to 13.6 ± 10.3 hours. Besides pre-treatment with mifepristone, gestational age and a history of delivery without Caesarean section were significant influencing factors in reducing the induction time. Conclusion: The induction interval can be significantly shortened by the prior administration of mifepristone. The combination of mifepristone and misoprostol or gemeprost is the most effective regimen for the medical termination of pregnancy.

[Use of misoprostol for induction of labor in case of fetal death or termination of pregnancy during second or third trimester of pregnancy: Efficiency, dosage, route of administration, side effects, use in case of uterine scar]

OBJECTIVE

Study, based on the literature, of the use of misoprostol for induction of labor in cases of second or third trimester fetal death or termination of pregnancy and define the different mode of administration.

MATERIALS AND METHODS

Bibliographic review using the Medline and Pubmed databases and the guidelines of the international professional societies. Selection of papers in French and English. Keywords used: misoprostol, termination of pregnancy, mid and third trimester, scarred uterus, previous cesarean section, uterine rupture.

RESULTS

Misoprostol is effective for induction of labor in case of second or third fetal death or termination of pregnancy. Comparing to oral route, vaginal route reduces the induction-expulsion time and the rate of patients remaining undelivered in the first 24 hours without increasing side effects. Oral route is a possible alternative if preferred by the patient. Sublingual route seems interesting but data are limited. The use of moderate doses (800-2400 μg/day) every 3 to 6 hours seems to be the best compromise between efficiency and tolerance. It is not possible to recommend a specific dosing schedule. The risk of uterine rupture in case of previous cesarean section justifies the use of minimum effective dose for these patients. In this case, it is recommended not to exceed a dose of 100 μg for each dose. The induction-birth period and doses of misoprostol required to induce labor are reduced when combined with mifepristone administered 36 to 48 hours before.

CONCLUSION

Misoprostol is effective and safe for induction of labor in case of second or third trimester fetal death or termination of pregnancy.

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.

Randomized controlled trial comparing efficacy between a vaginal misoprostol loading and non-loading dose regimen for second-trimester pregnancy termination

AIM

The aim of this study was to compare the efficacy of vaginal misoprostol loading dose regimen with non-loading dose regimen for termination of second-trimester pregnancy with live fetuses.

MATERIAL AND METHODS

A randomized controlled trial was conducted on pregnant women with a live fetus at 14-28 weeks. The patients were randomly allocated to receive either the vaginal misoprostol loading dose regimen (600 mcg, then 400 mcg every 6 h) or the non-loading dose regimen (400 mcg every 6 h). Failure to abort within 48 h was considered to be a failure.

RESULTS

Of 157 recruited women, 77 were assigned to be in group 1 (loading group) and 80 were in group 2 (non-loading group). The median abortion time was not statistically different between the groups (14.08; 95% confidence interval: 12.45-17.77 h and 14.58; 95% confidence interval: 12.8-17.27 h, P > 0.05). The rates of abortion within 24 h and 48 h were also comparable between the groups. Fever and chills were more common in the loading group. No other serious complications, such as postpartum hemorrhage and uterine rupture, were found.

CONCLUSION

Vaginal misoprostol in the loading dose regimen had a similar efficacy to the non-loading dose regimen but was associated with more adverse maternal effects.

Multiple-dose vaginal misoprostol and single-dose misoprostol plus oxytocin for termination of second-trimester pregnancy

OBJECTIVE

To compare 2 different methods-multiple doses of misoprostol and a combination of misoprostol and oxytocin-for termination of pregnancy in the second trimester.

METHODS

Between 2006 and 2008, 120 women undergoing termination of second-trimester pregnancy in 2 hospitals in Kermanshah, Iran, were enrolled in a randomized trial comparing 2 treatments. In each treatment group, an initial vaginal dose of 600 μg of misoprostol was placed in the posterior fornix. After 6 hours, an intravenous infusion of concentrated oxytocin was given to women in group A, and 400 μg of vaginal misoprostol was given every 6 hours to women group B, up to a maximum of 4 doses. The outcomes were compared via χ(2) and independent t tests.

RESULTS

Within 30 hours, 96.7% of women in group A and 96.7% of women in group B delivered successfully. The average duration between induction and delivery time was 12.3±6.0 hours in group A and 12.1±6.0 hours in group B (P>0.05).

CONCLUSION

The use of misoprostol with oxytocin, and multiple doses of misoprostol gave similar results for termination of pregnancy in the second trimester.

Clinical guidelines. Labor induction abortion in the second trimester

Labor induction abortion is effective throughout the second trimester. Patterns of use and gestational age limits vary by locality. Earlier gestations (typically 12 to 20 weeks) have shorter abortion times than later gestational ages, but differences in complication rates within the second trimester according to gestational age have not been demonstrated. The combination of mifepristone and misoprostol is the most effective and fastest regimen. Typically, mifepristone 200 mg is followed by use of misoprostol 24-48 h later. Ninety-five percent of abortions are complete within 24 h of misoprostol administration. Compared with misoprostol alone, the combined regimen results in a clinically significant reduction of 40% to 50% in time to abortion and can be used at all gestational ages. However, mifepristone is not widely available. Accordingly, prostaglandin analogues without mifepristone (most commonly misoprostol or gemeprost) or high-dose oxytocin are used. Misoprostol is more widely used because it is inexpensive and stable at room temperature. Misoprostol alone is best used vaginally or sublingually, and doses of 400 mcg are generally superior to 200 mcg or less. Dosing every 3 h is superior to less frequent dosing, although intervals of up to 12 h are effective when using higher doses (600 or 800 mcg) of misoprostol. Abortion rates at 24 h are approximately 80%-85%. Although gemeprost has similar outcomes as compared to misoprostol, it has higher cost, requires refrigeration, and can only be used vaginally. High-dose oxytocin can be used in circumstances when prostaglandins are not available or are contraindicated. Osmotic dilators do not shorten induction times when inserted at the same time as misoprostol; however, their use prior to induction using misoprostol has not been studied. Preprocedure-induced fetal demise has not been studied systematically for possible effects on time to abortion. While isolated case reports and retrospective reviews document uterine rupture during second-trimester induction with misoprostol, the magnitude of the risk is not known. The relationship of individual uterotonic agents to uterine rupture is not clear. Based on existing evidence, the Society of Family Planning recommends that, when labor induction abortion is performed in the second trimester, combined use of mifepristone and misoprostol is the ideal regimen to effect abortion quickly and completely. The Society of Family Planning further recommends that alternative regimens, primarily misoprostol alone, should only be used when mifepristone is not available.