Synthetic osmotic dilators with adjunctive misoprostol for same-day dilation and evacuation: a randomized controlled trial

Cervical preparation for dilation and evacuation at 12 to 24 weeks gestation

BACKGROUND

Abortion is a common procedure. Complications associated with abortion increase as gestational age increases. Cervical preparation is recommended prior to second trimester surgical abortion. Evidence is lacking as to the most effective methods of cervical preparation.

OBJECTIVES

To assess the effectiveness of cervical preparation methods for people undergoing second trimester surgical abortion at gestational age between 12 and 24 0/7 weeks.

SEARCH METHODS

We searched CENTRAL, MEDLINE ALL, Embase.com, Global Index Medicus, Scopus, and Google Scholar on 20 December 2021. We also searched reference lists, review articles, books, and conference proceedings. We contacted experts for information on other published or unpublished research. The COVID-19 pandemic greatly disrupted the writing and publication of this review; the search is outdated, but an updated search will be performed prior to the next update.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) investigating any cervical preparation method for second trimester surgical abortion from 12 to 24 weeks gestation.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods.

MAIN RESULTS

We identified 21 RCTs (3029 participants). Some trials were at high risk of detection and reporting bias. Prostaglandin versus osmotic dilators (4 studies, 373 participants; 12 6/7 to 20 weeks) Prostaglandin may result in little to no difference in ability to complete procedure (risk ratio [RR] 0.99, 95% confidence interval [CI] 0.95 to 1.03; low-certainty evidence), but probably leads to less dilation achieved (mean difference [MD] -3.58 mm, 95% CI -4.58 to -2.58; moderate-certainty evidence) when compared to osmotic dilators. Mifepristone plus 400 μg buccal misoprostol versus osmotic dilators (1 study, 49 participants; 15 0/7 to 18 0/7 weeks) Mifepristone plus misoprostol may have little to no effect on ability to complete procedure (RR 1.00, 95% CI 0.92 to 1.08; low-certainty evidence) and procedure time (MD -0.30, 95% CI -3.46 to 2.86) when compared to osmotic dilators. The combination may lead to less dilation achieved (MD -1.67 mm, 95% CI -3.19 to -0.15; low-certainty evidence) and increased need for additional dilation (RR 1.92, 95% CI 1.16 to 3.18; low-certainty evidence) compared to osmotic dilators. 400 μg buccal misoprostol plus osmotic dilators versus placebo plus osmotic dilators (4 studies, 545 participants; 13 to 23 6/7 weeks) Misoprostol plus osmotic dilators probably has no effect on ability to complete procedure (RR 0.99, 95% CI 0.96 to 1.02; moderate-certainty evidence), but probably increases dilation achieved (MD 1.83 mm, 95% CI 0.27 to 3.39; moderate-certainty evidence) and reduces need for additional dilation (RR 0.65, 95% CI 0.50 to 0.84; moderate-certainty evidence) and procedure time (MD -0.99 min, 95% CI -2.05 to 0.06; moderate-certainty evidence) compared to placebo plus osmotic dilators. Mifepristone plus osmotic dilators versus placebo plus osmotic dilators (1 study, 198 participants; 16 0/7 to 23 6/7 weeks) Mifepristone plus osmotic dilators probably has little to no effect on ability to complete procedure when compared to placebo plus osmotic dilators (RR 1.00, 95% CI 0.97 to 1.03; moderate-certainty evidence). Mifepristone plus osmotic dilators may reduce procedure time (2.46 min shorter: median, interquartile range, 9.12 min, 7.7 to 10.6; compared to 11.58 minutes, 10.0 to 13.1; low-certainty evidence) and probably increases dilation achieved (MD 2.00 mm, 95% CI 0.60 to 3.40; moderate-certainty evidence). There appears to be no effect on need for additional dilation. 400 μg buccal misoprostol plus osmotic dilators versus mifepristone plus osmotic dilators (1 study, 199 participants; 16 0/7 to 23 6/7 weeks) There is likely no difference in ability to complete procedure between groups (RR 0.99, 95% CI 0.96 to 1.02; moderate-certainty evidence). Misoprostol plus osmotic dilators does not appear to affect procedure time, dilation achieved, and need for additional dilation compared with mifepristone plus osmotic dilators. Mifepristone plus 400 μg buccal misoprostol plus osmotic dilators compared to 400 μg buccal misoprostol plus osmotic dilators (1 study, 96 participants; 19 to 23 6/7 weeks) Mifepristone plus misoprostol plus osmotic dilators may have little to no effect on procedure time, dilation achieved, or need for additional dilation compared with misoprostol plus osmotic dilators. 400 μg buccal or vaginal misoprostol plus osmotic dilators versus 400 μg buccal or vaginal misoprostol (1 study, 163 participants; 14 to 19 6/7 weeks) There is probably no difference between groups in ability to complete procedure (RR 1.00, 95% CI 0.98 to 1.02; moderate-certainty evidence). Misoprostol plus osmotic dilators likely increases dilation (MD 3.9 mm, 95% CI 3.1 to 4.7; moderate-certainty evidence) and reduces need for additional dilation (RR 0.77, 95% CI 0.63 to 0.93; moderate-certainty evidence). Laminaria versus synthetic osmotic dilators (1 study, 219 participants; 13 6/7 to 24 0/7 weeks) Laminaria japonica may reduce ability to complete procedure at first attempt compared with synthetic osmotic dilators (RR 0.85, 95% CI 0.75 to 0.96; low-certainty evidence). It is uncertain if there is a difference in procedure time between groups. Laminaria likely does not effect dilation achieved (RR 1.0, 95% CI 0.8 to 1.3; moderate-certainty evidence). Same-day Dilapan-S versus overnight laminaria (1 study, 69 participants; 13 6/7 to 17 6/7 weeks) Same-day Dilapan-S may increase procedure time (MD 2.20 min, 95% CI 0.10 to 4.30; low-certainty evidence); reduce dilation achieved (MD -11.70 mm, 95% CI -16.74 to -6.66; low-certainty evidence); and increase need for additional dilation (RR 2.83, 95% CI 1.47 to 5.46; low-certainty evidence) compared with laminaria. There appears to be no difference in ability to complete procedure.

AUTHORS' CONCLUSIONS

We identified a heterogeneous body of evidence comparing different cervical priming approaches. Compared with osmotic dilators plus placebo, misoprostol plus osmotic dilators probably reduces procedure time, increases pre-procedure cervical dilation, and reduces the number of people who need additional dilation. Compared with osmotic dilators plus placebo, mifepristone plus osmotic dilators may reduce procedure time and probably increases pre-procedure cervical dilation. Overnight laminaria may reduce procedure time, increase pre-procedure dilation, and reduce need for additional dilation compared to same-day Dilapan-S. Further studies are needed that focus on both provider and patient acceptability and satisfaction.

Efficacy of pharmacologic hemorrhage prophylactics in second-trimester abortions: a systematic review

OBJECTIVE

This study aimed to evaluate prophylactic uterotonics, antifibrinolytic medications, and vasoconstrictive agents in the prevention of hemorrhage during second-trimester abortions.

DATA SOURCES

PubMed, Embase (Elsevier platform), Evidence-Based Medicine Reviews (Ovid platform), and Web of Science were searched from database creation to October 30, 2023.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials, cohort studies, case-control studies, and case series evaluating pregnant individuals (between 13 0/7 and 27 6/7 weeks of gestation) who underwent dilation and evacuation and received prophylactic uterotonics (methylergonovine, carboprost, oxytocin, or misoprostol), antifibrinolytic medications (tranexamic acid), or vasoconstrictive agents (vasopressin, lidocaine with epinephrine) were included in the study. The outcomes of interest included postprocedural bleeding, rate of medications to treat bleeding, blood transfusion, reoperation, and transfer to a higher level of care for hemorrhage.

METHODS

Of note, 2 authors independently screened the abstracts using the Systematic Review Data Repository. A third reviewer resolved discrepancies. The full text of accepted abstracts was retrieved and assessed for eligibility by 2 independent authors. Eligible studies were independently assessed for quality and bias by 3 authors. A consensus review resolved discrepancies.

RESULTS

Among 5834 abstracts screened, 11 studies met the inclusion criteria: 5 randomized controlled trials, 3 retrospective cohort studies, and 3 case series, totaling 3857 individuals. The paucity of studies combined with the heterogeneity of included trials precluded the performance of the meta-analysis. Of note, 4 studies evaluating misoprostol were of overall low-quality evidence and primarily assessed misoprostol's use for cervical dilation. Thus, its efficacy in bleeding prophylaxis remains unclear. Moreover, 2 high-quality trials evaluating oxytocin concluded that oxytocin use resulted in decreased blood loss, without a difference in interventions to control bleeding. Furthermore, 2 studies provided moderate-quality evidence that paracervical vasopressin use decreased blood loss, particularly at advanced gestational ages, but subsequent intervention outcomes were not assessed. High-quality evidence evaluating methylergonovine found that this medication increased blood loss at the time of the procedure.

CONCLUSION

Current evidence on hemorrhage prophylaxis at the time of dilation and evacuation supports the use of intravenous oxytocin or paracervical vasopressin to decrease procedural blood loss, without an associated decrease in transfusion rate or use of other interventions. Future research on outcomes by gestational age can identify subgroups with the potential to derive the most benefit.

Adjuvant misoprostol or mifepristone for cervical preparation with osmotic dilators before dilation and evacuation

OBJECTIVES

This study aimed to compare effectiveness and safety of cervical preparation with osmotic dilators plus same-day misoprostol or overnight mifepristone prior to dilation and evacuation (D&E).

STUDY DESIGN

We conducted a retrospective cohort analysis of 664 patients initiating abortion between 18 and 22 weeks at an ambulatory health center. We abstracted medical record data from two consecutive 12-month periods in 2017 to 2019. All patients received overnight dilators plus: 600 mcg buccal misoprostol 90 minutes before D&E (period 1); 200 mg oral mifepristone at time of dilators (period 2). Our primary outcome was procedure time. We report frequency of patients experiencing any acute complication, defined as unplanned procedure (i.e., reaspiration, cervical laceration repair, uterine balloon tamponade) or hospital transfer and bleeding complications.

RESULTS

We observed higher mean procedure time in the mifepristone group (9.7 ± 5.3 minutes vs 7.9 ± 4.4, p = 0.004). After adjusting for race, ethnicity, insurance, body mass index, parity, prior cesarean, prior uterine surgery, gestational age, provider, trainee participation, and long-acting reversible contraception initiation, the difference remained statistically significant (relative change 1.09, 95% CI 1.01, 1.17) but failed to reach our threshold for clinical significance. The use of additional misoprostol was more common in the mifepristone group, but the use of an additional set of dilators was not different between groups. Acute complications occurred at a frequency of 4.1% in misoprostol group and 4.3% in mifepristone group (p = 0.90).

CONCLUSIONS

We found procedure time to be longer with adjunctive mifepristone compared to misoprostol; however, this difference is unlikely to be clinically meaningful. Furthermore, the frequency of acute complications was similar between groups.

IMPLICATIONS

Overnight mifepristone at the time of cervical dilator placement is a safe and effective alternative to adjuvant same-day misoprostol for cervical preparation prior to D&E and may offer benefits for clinic flow and patient experience.

Cervical preparation for second-trimester procedural abortion

PURPOSE OF REVIEW

To review the evidence-informed options for cervical preparation prior to second-trimester dilation and evacuation (D&E).

RECENT FINDINGS

As abortion restrictions increase and the number of abortion clinics and providers decreases, pregnant people are facing more barriers to abortion access. Those in need are now often required to travel for second-trimester abortion care, only to be faced with additional restrictions, such as mandatory waiting periods. Cervical preparation is recommended prior to D&E and takes time for effect. Given the increasing time required to obtain an abortion, patients and providers may prefer same-day cervical preparation to decrease the total time required. Options for same-day cervical preparation include misoprostol alone with single or serial doses, and misoprostol combined with osmotic dilators or transcervical balloon (Foley catheter). Same-day preparation may require additional clinical space to accommodate people after initiation of cervical preparation to manage side-effects and timing of the abortion. Overnight options are also used and more frequently later in the second trimester. Overnight options include mifepristone, osmotic dilators, and transcervical balloon and are often combined with same-day misoprostol. Medication alone preparation is well tolerated and effective in the second trimester, with the addition of mechanical methods with advancing gestation. With many options and combinations being safe and effective, providers can be dynamic and alter approach with supply shortages, adjust to different clinical settings, consider patient medical and surgical factors, and accommodate provider and patient preferences.

SUMMARY

Multiple pharmacologic and mechanical options have been shown to be safe and effective for cervical preparation prior to D&E. Consideration for multiple factors should influence the method of cervical preparation and methods may vary by patient, provider and setting.

Same-Day Compared With Overnight Cervical Preparation Before Dilation and Evacuation Between 16 and 19 6/7 Weeks of Gestation: A Randomized Controlled Trial

We performed a double-blind, placebo-controlled, randomized noninferiority trial to compare same-day osmotic dilators plus misoprostol with overnight osmotic dilators alone for cervical preparation before dilation and evacuation (D&E) between 16 0/7 and 19 6/7 weeks of gestation. The primary outcome was procedure time. The study was halted early owing to poor accrual. However, the median procedure time was 5.7 minutes in the same-day group compared with 4.2 minutes in the overnight group. The median absolute difference in procedure time was 1.5 minutes, which corresponded to a 35% increase in procedure time (relative difference 35%, one-sided 95% CI -Inf to 52%). Same-day cervical preparation with osmotic dilators plus buccal misoprostol before D&E may be a timely option. Clinical Trial Registration: ClinicalTrials.gov, NCT03002441.

Pain, Side Effects, and Abortion Experience Among People Seeking Abortion Care in the Second Trimester

Background:

There is limited documentation about pain and side effects associated with dilation and evacuation (D&E) abortion, yet, pain and side effects are important factors that can affect a client's abortion experience. In 2016, Hope Clinic for Women, an independent abortion clinic in Illinois, altered its cervical preparation protocols before D&E to reduce the total time of the abortion process and improve the client experience. This analysis addresses the gap in data on client experience of abortion in the later second trimester by evaluating pain, side effects, and acceptability by gestational age.

Methods:

Abortion clients obtaining services at the clinic between March 2017 and June 2018 were eligible to participate if they had viable singleton pregnancies of 16–23.6 weeks' gestation, spoke English, and were at least 18 years old. Eligible participants completed a two-part survey about their abortion experience.

Results:

We found that respondents seeking abortion care at later gestations in the second trimester were more likely to report pain during their abortions. We did not find any association between side effects and gestational age.

Conclusion:

Although most respondents were prepared for the pain they experienced, some reported experiencing more pain than they expected, and more effective pain relief was commonly reported as a way to improve the service. More research on patient experiences of later abortion is needed, particularly on experiences of pain and options for pain management.

Expulsion of a fragmented laminaria one week after a same-day dilation and evacuation procedure

We describe a complication from same-day cervical preparation with simultaneous use of Aquacryl hydrogel osmotic dilator, laminaria and misoprostol vaginally for a same-day dilation and evacuation procedure at 19 weeks' gestation. The laminaria fragmented and embedded in the cervix at the time of procedure. Removal was unsuccessful in clinic and the patient was discharged on one week of antibiotics. The patient returned after the administration of misoprostol vaginally and the surgeon found the fragment in the vagina. We cannot conclude if the fragment was expelled with misoprostol use or prior to its administration.

Cervical priming before surgical abortion between 14 and 24 weeks: a systematic review and meta-analyses for the National Institute for Health and Care Excellence-new clinical guidelines for England

OBJECTIVE

This study aimed to determine the optimal cervical priming regimen before surgical abortion between 14⁺⁰ and 24⁺⁰ weeks' gestation.

DATA SOURCES

Embase, MEDLINE, and the Cochrane Library were searched for publications up to February 2020. Experts were consulted for any ongoing or missed trials.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials, published in English after 1985, that compared (1) mifepristone, misoprostol, and osmotic dilators against each other, alone or in combination; (2) different doses of mifepristone and misoprostol; (3) different intervals between priming and abortion; or (4) different routes of administration of misoprostol were included.

METHODS

Risk of bias was assessed using the Cochrane Collaboration checklist for randomized controlled trials, and data were meta-analyzed in Review Manager 5.3. Dichotomous outcomes were analyzed as risk ratios using the Mantel-Haenszel method, and continuous outcomes were analyzed as mean differences using the inverse variance method. Fixed effects models were used when there was no significant heterogeneity (I²<50%), random effects models were used for moderate heterogeneity (I²≤50% and <80%), and evidence was not pooled when there was high heterogeneity (I²≥80%). Subgroup analyses were undertaken based on parity where available. The overall quality of the evidence was assessed using Grades of Recommendation Assessment, Development, and Evaluation.

RESULTS

A total of 15 randomized controlled trials (N=2454) were included and showed decreased difficulty of procedure and/or increased cervical dilation and decreased patient acceptability with regimens that included dilators compared with those that did not include dilators; increased preoperative expulsion of the pregnancy with sublingual misoprostol and mifepristone compared with sublingual misoprostol alone; increased difficulty of procedure with dilators and misoprostol compared with dilators and mifepristone; decreased difficulty of procedure with dilators and mifepristone compared with dilators alone; and increased cervical dilation when dilators were placed the day before abortion compared with the same day.

CONCLUSION

Considered alongside clinical expertise, the published data support the use of osmotic dilators, misoprostol, or mifepristone before abortion for pregnancies at 14⁺⁰ to 16⁺⁰ weeks' gestation; osmotic dilators or misoprostol for pregnancies at 16⁺¹ to 19⁺⁰ weeks' gestation; and osmotic dilators alone or with mifepristone for pregnancies at 19⁺¹ to 24⁺⁰ weeks' gestation. The effectiveness of pharmacologic agents alone beyond 16⁺⁰ weeks' gestation and the optimal timing of dilator placement remain important questions for future research.

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.

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.

Current and potential methods for second trimester abortion

Medical and surgical methods can both be recommended for second trimester abortion (after 12-weeks of gestational age). Induced abortion with a mifepristone and misoprostol regimen is the preferred approach; where mifepristone is not available, misoprostol alone for medical abortion is also effective. Dilation and evacuation (D&E) is the procedure of choice for surgical abortions, and adequate cervical preparation contributes significantly to safety. Availability of drugs and instruments, ability to provide pain control, provider skill and comfort, client preference, cultural considerations, and local legislation all influence the method of abortion likely to be performed in a given setting. Both surgical and modern medical methods are safe and effective when provided by a trained, experienced provider.

Induction of labor in patients with an unfavorable cervix after a cesarean using an osmotic dilator versus vaginal prostaglandin

BACKGROUND

Trial of labor after cesarean (TOLAC) is a viable option for safe delivery. In some cases cervical ripening and subsequent labor induction is necessary. However, the commonly used prostaglandins are not licensed in this subgroup of patients and are associated with an increased risk of uterine rupture.

METHODS

This cohort study compares maternal and neonatal outcomes of TOLAC in women (n=82) requiring cervical ripening agents (osmotic dilator vs. prostaglandins). The initial Bishop scores (BSs) were 2 (0-5) and 3 (0-5) (osmotic dilator and prostaglandin group, respectively). In this retrospective analysis, Fisher's exact test, the Kruskal-Wallis rank sum test and Pearson's chi-squared test were utilized.

RESULTS

Vaginal birth rate (including operative delivery) was 55% (18/33) in the osmotic dilator group vs. 51% (25/49) in the dinoprostone group (P 0.886). Between 97% and 92% (32/33 and 45/49) (100%, 100%) of neonates had an Apgar score of >8 after 1 min (5, 10 min, respectively). The time between administration of the agent and onset of labor was 36 and 17.1 h (mean, Dilapan-S® group, dinoprostone group, respectively). Time from onset of labor to delivery was similar in both groups with 4.4 and 4.9 h (mean, Dilapan-S® group, dinoprostone group, respectively). Patients receiving cervical ripening with Dilapan-S® required oxytocin in 97% (32/33) of cases. Some patients presented with spontaneous onset of labor, mostly in the dinoprostone group (24/49, 49%). Amniotomy was performed in 64% and 49% (21/33 and 24/49) of cases (Dilapan-S® group and dinoprostone group, respectively).

CONCLUSIONS

This pilot study examines the application of an osmotic dilator for cervical ripening to promote vaginal delivery in women who previously delivered via cesarean section. In our experience, the osmotic dilator gives obstetricians a chance to perform induction of labor in these women.

Update on second-trimester surgical abortion

PURPOSE OF REVIEW

To review the recent literature on surgical second-trimester abortion, with specific attention to cervical preparation techniques.

RECENT FINDINGS

Confirming previous studies, a recent retrospective observational cohort study, including 54 911 abortions, estimated the total abortion-related complication rate to be 0.41% for second-trimester or later procedures. Cervical preparation is known to reduce risks associated with second-trimester dilation and evacuation (D&E). When considering adjuncts to osmotic dilators for cervical preparation prior to D&E after 16 weeks, both misoprostol and mifepristone are effective alone and in combination or as adjuncts to osmotic dilators. Misoprostol consistently has been shown to cause more pain and cramping than placebo, but is an effective adjunct to osmotic dilators after 16 weeks. Although mifepristone has fewer side-effects, at its current price, it may not be as cost-effective as misoprostol.

SUMMARY

Second-trimester abortion is safe. The use of mifepristone and misoprostol for second-trimester abortion has improved safety and efficacy of medical and surgical methods when used alone or in combination and as adjuncts to osmotic dilators. An important aspect of D&E, cervical preparation, is not a one-size-fits-all practice; the approach and methods are contingent on patient, provider and setting and should consider all the evidence-based options.