Abstract
Objective
The aim of this study was to report on the safety and efficacy of an evidence-based medical abortion regimen utilizing 200 mg of mifepristone orally followed by home use of 800 mcg misoprostol buccally 24–48 h later through 63 days estimated gestational age.
Study design
We analyzed outcomes in women presenting for medical abortion between April 1, 2006, and May 31, 2011, using an evidence-based alternative to the United States Food and Drug Administration (FDA)-approved regimen. Cases were identified for this descriptive study from our electronic practice management (EPM) database, and our electronic database on adverse events was queried for information on efficacy and safety. The primary outcome was successful abortion. Logistic regression was used to identify predictors of successful abortion.
Results
Among the 13,373 women who completed follow-up, efficacy of the regimen was 97.7%. Efficacy was highest at 29 to 35 days (98.8%) and 36 to 42 days (98.8%) of gestation and lowest at 57 to 63 days (95.5%). The odds of needing aspiration for any reason were greatest at higher gestational ages. Rates of infection requiring hospitalization and rates of transfusion were 0.01 and 0.03%, respectively.
Conclusions
An evidence-based regimen of 200 mg of mifepristone orally followed by home use of 800 mcg of buccal misoprostol 24–48 h later is safe and effective through 63 days estimated gestational age. Further, the need for aspiration for any reason was low, and hospitalization was rare.
Implications
This study reinforces the safety and efficacy of the evidence-based regimen for medical abortion (200 mg mifepristone orally followed by home use of 800 mcg of misoprostol buccally 24–48 h later) through 63 days estimated gestational age, and contributes to the existing evidence against restrictions requiring use of the FDA-approved regimen.
Keywords: Medical abortion, Mifepristone, First-trimester abortion, Evidence-based regimen, Buccal misoprostol, Efficacy
1. Introduction
The United States Food and Drug Administration (FDA) approved the use of mifepristone and misoprostol for pregnancy termination in 2000. The regimen, labeled for use through 49 days estimated gestational age, required a minimum of three visits to the healthcare provider. Six hundred milligrams of mifepristone was taken orally at Visit 1, followed in 2 days by misoprostol 400 mcg, also taken orally. A third follow-up visit was required in 14 days to ensure that the abortion was complete. The efficacy of this regimen ranged from 92 to 97% [1-3]. Publications soon followed providing an evidence base for alterations to the regimen. Alterations included a lower dose of mifepristone, different routes of administration of misoprostol, variations in the timing of misoprostol administration, home use of misoprostol, and increasing the gestational age limit for the regimen [4-11]. A recent publication confirmed the low rate of significant adverse events with use of the evidence-based regimen [11].
In 2008, a prospective study was published describing the use of 200 mg of mifepristone followed in 24 to 36 h by 800 mcg of buccal misoprostol for pregnancy termination to 63 days of gestation with a success rate for the regimen of 96.2% [8]. Despite the growing literature supporting evidence-based provision of medical abortion, some providers are required by law to limit the provision of medical abortion to that regimen, which was FDA-approved more than a decade ago [12]. The goal of the current study was to assess, in a much larger cohort of patients, the safety and efficacy of an evidence-based medical abortion regimen utilizing 200 mg of mifepristone orally followed by home use of 800 mcg of misoprostol buccally 24–48 h later through 63 days estimated gestational age.
2. Materials and methods
2.1. Medical abortion protocols and monitoring
Our large network of urban healthcare centers includes 19 health centers providing approximately 15,000 abortions per year, of which about 30% are medical abortions. Demographic information, treatment dates, and diagnostic codes for all patients were retrieved using the electronic practice management (EPM) billing system. Some clinical information was retrieved from an electronic medical records (EMR) system, which was gradually implemented across all study sites between 2008 and 2010. All patients undergo an ultrasound examination for pregnancy dating prior to abortion. The clinician administering the medication abortion performed and interpreted the ultrasound. All clinicians had undergone the same standardized training and were monitored regularly to ensure accuracy and to maintain consistency. Ultrasound machines using a Hadlock scale calculated gestational age in days; herein, we analyze and report gestational age in 7-day increments (e.g., 22 to 28 days). Since April 2006, our medical abortion regimen has consisted of 200 mg of mifepristone taken orally at the health center followed by 800 mcg of buccal misoprostol used by the patient at home 24 to 48 h later. Medical protocols during the study period allowed for repeat doses of misoprostol for patients who had an incomplete medical abortion. Data on which patients received a repeat dose are not available from the EPM system, but only in the EMR system; therefore, for patients seen at sites that had not yet implemented EMR at the time of treatment, information on whether a repeat dose of misoprostol was given is not available. For the first 3 years of the study period, the upper gestational age limit for this regimen was 56 days. In February 2009, based on newly published data, the upper limit was increased to 63 days [8]. All patients were scheduled to return in 7 to 14 days for a postabortion evaluation. Beginning in 2007, all patients also received routine antibiotic coverage beginning on the day of the mifepristone administration. The standard antibiotic regimen was a 7-day course of doxycycline (100 mg twice a day), with an alternative regimen of one dose of azithromycin (1 g) for cases in which doxycycline was contraindicated.
Our EPM database contains information on all patients undergoing medical abortion, including patient demographics and the ultrasound-determined gestational age. We also maintain a separate electronic database of adverse events including ongoing pregnancy, aspiration for symptoms and/or retained products of conception, infection requiring hospitalization, and hemorrhage requiring transfusion.
2.2. Statistical methods
Bivariate and multivariate logistic regression were used to assess predictors of successful medical abortion. Covariates available in our data set were poverty level, race/ethnicity, gestational age, and patient age; other patient-level data were not available. Results were considered statistically significant at p < .05. Statistical analysis was performed using Stata/SE 11.2 (College Station, TX).
The primary outcome of interest was successful abortion. A successful abortion was defined as expulsion of the pregnancy without the need for aspiration. Patients who required aspiration for an ongoing pregnancy or symptoms such as pain or bleeding were considered to have had unsuccessful medical abortions. We queried our adverse events database to identify continuing pregnancies (those pregnancies with documented fetal growth or cardiac activity seen at the follow-up), all cases of aspiration, and hospitalization for either infection or transfusion. We cross-checked this against the list of postprocedure visits in our EPM system in order to ensure that all cases had been identified.
Institutional review board (IRB) approval was obtained from the Ethical and Independent Review Service of Independence, MO, and an exemption for analysis of the existing data was granted by the Princeton University IRB.
3. Results
3.1. Sample description
For this descriptive study, we queried our EPM database and identified 15,890 patients who had a medical abortion between April 1, 2006, and May 31, 2011. During the period under review, medical abortions were provided at 14 different clinic sites belonging to our network in one urban area, all using the same evidence-based protocol. There were 2470 (15.5%) patients who failed to return for a follow-up visit and were excluded from analysis. An additional 20 patients were excluded from the analysis due to missing data on gestational age, and a further 27 patients were excluded because they did not complete the medical abortion (these patients either changed their mind and chose a surgical abortion, were ineligible for a medical abortion because they were beyond the 63-day gestational limit, or began the regimen but did not take all of the medications). This left 13,373 patients for analysis.
Demographic characteristics of the 13,373 women who had a medical abortion between April 1, 2006, and May 31, 2011, and who returned for follow-up are shown in Table 1. Half of the women were between the ages of 18 and 24, and small proportions were under the age of 18 (4.5%) or 40 or older (2.2%). Nearly half of women identified as Hispanic or Latino, and 72% reported an income at or below the poverty line. The most frequent gestational age in our data set was 43 to 49 days (36.0%), and the least frequent was 22 to 28 days (4.1%).
Table 1.
Demographic characteristics of women having a medical abortion with mifepristone 200 mg and misoprostol 800 mcg buccally (N= 13,373)
| n | % | |
|---|---|---|
| Gestational age (days) | ||
| 22–28 | 554 | 4.1 |
| 29–35 | 1080 | 8.1 |
| 36–42 | 2495 | 18.7 |
| 43–49 | 4816 | 36.0 |
| 50–56 | 3142 | 23.5 |
| 57–63 | 1286 | 9.6 |
| Poverty level (% FPL) | ||
| 0–100 | 9679 | 72.4 |
| > 100 | 3694 | 27.6 |
| Race/ethnicity | ||
| Hispanic/Latino | 6215 | 46.5 |
| White | 3235 | 24.2 |
| African American | 1263 | 9.5 |
| Asian | 1172 | 8.8 |
| Other/declined | 1487 | 11.1 |
| Patient age (years) | ||
| < 18 | 605 | 4.5 |
| 18–24 | 6684 | 50.0 |
| 25–29 | 3317 | 24.8 |
| 30–34 | 1613 | 12.1 |
| 35–39 | 855 | 6.4 |
| 40+ | 299 | 2.2 |
3.2. Frequency and predictors of successful abortion
Termination of pregnancy with 200 mg of oral mifepristone followed by 800 mcg of buccal misoprostol 24–48 h later was successful among 97.7% of women who completed follow-up. Only 307 (2.3%) of the 13,373 women included in this study underwent aspiration for any reason. Specifically, 70 (0.5%) women had a continuing pregnancy, and 237 (1.8%) women required aspiration for reasons other than continuing pregnancy, most commonly due to reported symptoms of pain and/or bleeding. Data on the need for a repeat dose of misoprostol were available from a subset of women from clinics in which the EMR system was used, which included 7335 women (54.8% of the total sample). Of these 7335 women, 87 (1.2%) received a repeat dose of misoprostol.
Table 2 shows the proportion of patients requiring aspiration for ongoing pregnancy or for symptoms, such as heavy bleeding, by gestational age. The proportion with ongoing pregnancy ranged from 0.15% for those at 36 to 42 days of gestation to 1.63% at 57 to 63 days of gestation. Compared with the reference category (43 to 49 days), odds of ongoing pregnancy were greater for those at the highest gestational age. The proportion of women treated with aspiration for symptoms, not ongoing pregnancy, ranged from 0.65 to 2.49%. The incidence of hospitalization for infection or hemorrhage requiring transfusion was very low (Table 3). In total, six women required hospitalization for any reason (two women were hospitalized for infection, and four were hospitalized for transfusion), and incidence was at or below 0.1% among all gestational ages.
Table 2.
Aspiration for ongoing pregnancy, symptoms or any indication among those who completed follow-up, by gestational age.
| Gestational age | Aspiration for ongoing pregnancy n (%) |
OR | 95% CI | Aspiration for symptoms n (%) |
OR | 95% CI | Aspiration for any reason * n (%) |
OR | 95% CI |
|---|---|---|---|---|---|---|---|---|---|
| 22–28 days | 4 (0.72) | 2.69 | 0.87–8.27 | 11 (1.99) | 1.39 | 0.73–2.65 | 15 (2.71) | 1.39 | 0.80–2.43 |
| 29–35 days | 5 (0.46) | 1.72 | 0.61–4.83 | 7 (0.65) | 0.45 | 0.21–0.98 | 13 (1.20) | 0.61 | 0.34–1.10 |
| 36–42 days | 4 (0.16) | 0.59 | 0.19–1.82 | 25 (1.00) | 0.70 | 0.44–1.10 | 30 (1.20) | 0.61 | 0.40–0.92 |
| 43–49 days | 13 (0.27) | ref | 69 (1.43) | ref | 94 (1.95) | ref | |||
| 50–56 days | 23 (0.73) | 2.72 | 1.38–5.39 | 64 (2.04) | 1.43 | 1.01–2.02 | 97 (3.09) | 1.60 | 1.20–2.13 |
| 57–63 days | 21 (1.63) | 6.13 | 3.06–12.28 | 32 (2.49) | 1.76 | 1.15–2.80 | 58 (4.51) | 2.37 | 1.70–3.31 |
| Totals | 70 (0.5) | 237 (1.8) | 307 (2.3) |
OR: odds ratio; CI: confidence interval
This column includes 29 cases wherein reason for aspiration is unknown.
Table 3.
Hospitalizations for infection or transfusion in women having a medical abortion with mifepristone 200 mg and misoprostol 800 mcg buccally (N=13,373)
| Gestational age | Patients n |
Infections n (%) |
Transfusions n (%) |
|---|---|---|---|
| 22–28 days | 554 | 0 (0.00) | 1 (0.18) |
| 29–35 days | 1080 | 1 (0.09) | 0 (0.00) |
| 36–42 days | 2495 | 0 (0.00) | 0 (0.00) |
| 43–49 days | 4816 | 1 (0.02) | 0 (0.00) |
| 50–56 days | 3142 | 0 (0.00) | 3 (0.10) |
| 57–63 days | 1286 | 0 (0.00) | 0 (0.00) |
| Total | 13,373 | 2 (0.01) | 4 (0.03) |
In a multivariate logistic regression model (Table 4), poverty level and race/ethnicity were not significant predictors of successful abortion. Certain categories of gestational age were significantly associated with success; compared with the reference category (43 to 49 days), those at 36 to 42 days of gestation had greater odds of success, whereas those at 50 to 56 days and 57 to 63 days had lower odds of success. Compared with the reference category (18 to 24), those in the middle three age groups had significantly lower odds of success, but differences for those in the youngest (17 and under) and highest (40 and older) age groups were not significant.
Table 4.
Factors associated with successful medical abortion in women using mifepristone 200 mg and misoprostol 800 mcg buccally (N=13,373)
| Successful n (%) |
Unsuccessful n (%) |
OR | 95% CI | |
|---|---|---|---|---|
| Gestational age (days) | ||||
| 22–28 | 539 (97.3) | 15 (2.7) | 0.72 | 0.41–1.25 |
| 29–35 | 1067 (98.8) | 13 (1.2) | 1.68 | 0.94–3.01 |
| 36–42 | 2465 (98.8) | 30 (1.2) | 1.65 | 1.09–2.50 |
| 43–49 | 4722 (98.1) | 94 (2.0) | Ref | |
| 50–56 | 3045 (96.9) | 97 (3.1) | 0.62 | 0.47–0.83 |
| 57–63 | 1228 (95.5) | 58 (4.5) | 0.42 | 0.30–0.58 |
| Total patients | 13,066 (97.7) | 307 (2.3) | ||
| Poverty level (% FPL) | ||||
| 0–100 | 9466 (97.8) | 213 (2.2) | 0.95 | 0.74–1.23 |
| > 100 | 3600 (97.5) | 94 (2.5) | Ref | |
| Race/ethnicity | ||||
| Hispanic/Latino | 6074 (97.7) | 141 (2.3) | Ref | |
| White | 3163 (97.8) | 72 (2.2) | 1.02 | 0.76–1.37 |
| African American | 1228 (97.2) | 35 (2.8) | 0.90 | 0.62–1.31 |
| Asian | 1146 (97.8) | 26 (2.2) | 1.02 | 0.67–1.57 |
| Other/declined | 1454 (97.8) | 33 (2.2) | 1.08 | 0.74–1.59 |
| Patient age (years) | ||||
| < 18 | 597 (98.7) | 8 (1.3) | 1.44 | 0.70–2.98 |
| 18–24 | 6560 (98.1) | 124 (1.9) | Ref | |
| 25–29 | 3233 (97.5) | 84 (2.5) | 0.72 | 0.54–0.96 |
| 30–34 | 1556 (96.5) | 57 (3.5) | 0.51 | 0.37–0.70 |
| 35–39 | 829 (97.0) | 26 (3.0) | 0.58 | 0.37–0.89 |
| 40+ | 291 (97.3) | 8 (2.7) | 0.68 | 0.33–1.40 |
OR, odds ratio; CI, confidence interval.
3.3. Loss to follow-up
A comparison of patients who completed follow-up and those who were lost to follow-up is presented in Table 5. Compared with patients at 43 to 49 days of gestation, patients at higher gestational ages were more likely to be lost to follow-up. For patients with incomes at or below the Federal Poverty Level (FPL), the odds of being lost to follow-up were greater than those above FPL. Odds of being lost to follow-up were greater for those younger than 18 (compared with those 18 to 24) and lower for those aged 40 and older.
Table 5.
Loss to follow-up analysis among women having a medical abortion with mifepristone 200 mg and misoprostol 800 mcg buccally (N=13,373)
| Completed follow-up n (%) |
Lost to follow-up n (%) |
ORa | 95% CI | |
|---|---|---|---|---|
| Gestational age (days) | ||||
| 22–28 | 554 (85.1) | 97 (14.9) | 1.00 | 0.79–1.25 |
| 29–35 | 1080 (86.3) | 172 (13.7) | 0.91 | 0.76–1.08 |
| 36–42 | 2495 (85.6) | 419 (14.4) | 0.96 | 0.84–1.09 |
| 43–49 | 4816 (85.1) | 845 (14.9) | Ref | |
| 50–56 | 3142 (83.0) | 645 (17.0) | 1.17 | 1.05–1.31 |
| 57–63 | 1286 (81.7) | 288 (18.3) | 1.28 | 1.10–.48 |
| Poverty level (% FPL) | ||||
| 0–100 | 9679 (83.7) | 1887 (16.3) | 1.24 | 1.12–1.38 |
| > 100 | 3694 (86.5) | 579 (13.6) | ||
| Race/ethnicity | ||||
| Hispanic/Latino | 6215 (84.1) | 1173 (15.9) | ||
| White | 3235 (83.4) | 643 (16.6) | 1.05 | 0.95–1.17 |
| African American | 1263 (82.8) | 262 (17.2) | 1.10 | 0.95–1.27 |
| Asian | 1172 (91.1) | 115 (8.9) | 0.52 | 0.43–0.64 |
| Other/declined | 1487 (84.5) | 273 (15.5) | 0.97 | 0.84–1.12 |
| Patient age (years) | ||||
| < 18 | 605 (80.0) | 152 (20.0) | 1.42 | 1.17–1.71 |
| 18–24 | 6684 (84.9) | 1186 (15.1) | ||
| 25–29 | 3317 (83.7) | 646 (16.3) | 1.10 | 0.99–1.22 |
| 30–34 | 1613 (84.8) | 289 (15.2) | 1.01 | 0.88–1.16 |
| 35–39 | 855 (84.6) | 156 (15.4) | 1.03 | 0.86–1.23 |
| 40+ | 299 (89.0) | 37 (11.0) | 0.70 | 0.49–0.99 |
OR, odds ratio; CI, confidence interval.
OR represents odds of being lost to follow-up.
4. Discussion
4.1. General implications
This study demonstrates that the evidence-based regimen for medical abortion (mifepristone 200 mg orally followed by home use of misoprostol 800 mcg buccally 24–48 h later) is highly effective through 63 days estimated gestational age, with an overall success rate of 97.7%. This is higher than the efficacy rates reported in two pivotal trials used in submission for FDA approval of mifepristone,[1,2] yet utilizes one-third the dose of mifepristone (200 mg rather than 600 mg) and buccal administration and home use of misoprostol rather than oral administration in the clinic. Repeat dosing of misoprostol was administered in only 1.2% of patients for whom this information is available, and given the way in which the EMR system was implemented across study sites, we can assume that this rate would be representative of the entire sample. Although efficacy is lower at later gestational ages, even in the 57- to 63-day range, this evidence-based regimen was still more effective than rates reported in the FDA-approved regimen, which sets the upper gestational age limit at 49 days. Furthermore, the rates of unsuccessful abortion in this study are lower than the rates reported in the two trials that were initially submitted to the FDA for approval of mifepristone. This study adds to the growing literature supporting provision of medical abortion using evidence-based regimens, and supports the conclusion that legislative efforts to restrict medical abortion to the FDA regimen are based on political goals to restrict abortion services, not efficacy or patient safety.
4.2. Limitations
Our study has some limitations. It is retrospective in nature and relies on the accuracy of our EPM database. However, review of our EPM system has shown a high degree of accuracy when compared with patient records [13]. In addition, we are not a closed system, and it is possible and even likely that some patients who experienced complications did not return to us for care. However, since many patients need to pay for aftercare obtained outside our system, but not within our system, it is more likely than not that the patients who did not return for follow-up did so because they did not feel that they needed follow-up, rather than that they were experiencing a complication. In that case, excluding them from our analysis would have tended to overestimate, rather than underestimate, the need for aspiration in our population. We based our analysis of efficacy only on those patients who did return for a follow-up visit, so we cannot exclude the possibility of additional visits or treatment elsewhere.
Loss to follow-up is common in studies of medical abortion, as many patients may determine on their own that their abortion is complete and that follow-up is not needed. The rate of loss to follow-up in this study (15.5%) is lower than loss to follow-up found in other clinical medical abortion studies, which report loss of follow-up of 18 to 45% [14-17]. We found that loss to follow-up was significantly more common among those at higher gestational ages; given that odds of success are lower among those with more advanced pregnancies, it is possible that this study underestimates the true odds of unsuccessful abortion. Loss to follow-up was significantly higher among the youngest age group and lower among the oldest age group, but as these age categories were unrelated to whether the abortion was successful, we do not believe that these differences would systematically bias our results.
4.3. Conclusion
In summary, an evidence-based regimen of mifepristone 200 mg orally followed by misoprostol 800 mcg buccally 48–72 h later is safe and effective through 63 days estimated gestational age. Further, need for aspiration for any reason was low, the chance of needing aspiration increased with gestational age at the time of medical abortion, and the frequency of hospitalization was rare. This study reinforces the safety and efficacy of the evidence-based regimen for medical abortion, and contributes to the evidence against restrictions that require use of the FDA-approved regimen.
Footnotes
Funding source: Planned Parenthood Federation of America (MG and DN) and Eunice Kennedy Shriver National Institute of Child Health and Human Development, grant no. 2R24HD047879 (KC).
Disclaimer: The findings and conclusions in this article are those of the authors and do not necessarily represent the views of Planned Parenthood Federation of America Inc.
References
- 1.Peyron R, Aubeny E, Targosz V, Silvestre L, Renault M, Elkik F, et al. Early termination of pregnancy with mifepristone (RU-486) and the orally active prostaglandin misoprostol. N Engl J Med. 1993;328:1509–13. doi: 10.1056/NEJM199305273282101. [DOI] [PubMed] [Google Scholar]
- 2.Aubeny E, Peyron R. Termination of early pregnancy (up to and after 63days of amenorrhea) with mifepristone (RU 486) and increasing doses of misoprostol (vol 40, pg 85, 1995) Int J Fertil Menopausal Stud. 1996;41:56. [PubMed] [Google Scholar]
- 3.Spitz I, Bardin C, Benton L, Robbins A. Early pregnancy termination with mifepristone and misoprostol in the United States. N Engl J Med. 1998;338:1241–7. doi: 10.1056/NEJM199804303381801. [DOI] [PubMed] [Google Scholar]
- 4.Schaff E, Eisinger S, Stadalius L, Franks P, Gore B, Poppema S. Low-dose mifepristone 200 mg and vaginal misoprostol for abortion. Contraception. 1999;59:1–6. doi: 10.1016/s0010-7824(98)00150-4. [DOI] [PubMed] [Google Scholar]
- 5.World Health Organization Task Force on Post-Ovulatory Methods of Fertility Regulation. Comparison of two doses of mifepristone in combination with misoprostol for early medical abortion: a randomised trial. Br J Obstet Gynaecol. 2000;107:524–30. doi: 10.1111/j.1471-0528.2000.tb13273.x. [DOI] [PubMed] [Google Scholar]
- 6.Schaff E, Fielding S, Westhoff C, Ellertson C, Eisinger S, Stadalius L, et al. Vaginal misoprostol administered 1, 2, or 3 days after mifepristone for early medical abortion—a randomized trial. JAMA. 2000;284:1948–53. doi: 10.1001/jama.284.15.1948. [DOI] [PubMed] [Google Scholar]
- 7.Schaff E, Fielding S, Westhoff C. Randomized trial of oral versus vaginal misoprostol at one day after mifepristone for early medical abortion. Contraception. 2001;64:81–5. doi: 10.1016/s0010-7824(01)00229-3. [DOI] [PubMed] [Google Scholar]
- 8.Winikoff B, Dzuba IG, Creinin MD, Crowden WA, Goldberg AA, Gonzales J, et al. Two distinct oral routes of misoprostol in mifepristone medical abortion: a randomized controlled trial. Obstetrics & Gynecology. 2008;112:1303–10. doi: 10.1097/AOG.0b013e31818d8eb4. [DOI] [PubMed] [Google Scholar]
- 9.Winikoff B, Dzuba IG, Chong E, Goldberg AB, Lichtenberg ES, Ball C, et al. Extending outpatient medical abortion services through 70 days of gestational age. Obstet Gynecol. 2012;120:1070–6. doi: 10.1097/aog.0b013e31826c315f. [DOI] [PubMed] [Google Scholar]
- 10.Fjerstad M, Sivin I, Lichtenberg ES, Trussell J, Cleland K, Cullins V. Effectiveness of medical abortion with mifepristone and buccal misoprostol through 59 gestational days. Contraception. 2009;80:282–6. doi: 10.1016/j.contraception.2009.03.010. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Cleland K, Creinin MD, Nucatola D, Nshom M, Trussell J. Significant adverse events and outcomes after medical abortion. Obstet Gynecol. 2013;121:166–71. doi: 10.1097/aog.0b013e3182755763. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Boonstra H. Medication abortion restrictions burden women and providers—and threaten US trend toward very early abortion. Guttmacher Policy Rev. 2013;16:18–23. [Google Scholar]
- 13.Steward R, Melamed A, Kim R, Nucatola D, Gatter M. Infection and extramural delivery with use of digoxin as a feticidal agent. Contraception. 2012;85:150–4. doi: 10.1016/j.contraception.2011.01.005. [DOI] [PubMed] [Google Scholar]
- 14.Grossman DA, Grindlay K, Buchacker T, Potter JE, Schmertmann CP. Changes in service delivery patterns after introduction of telemedicine provision of medical abortion in Iowa. Am J Public Health. 2013;103:73–8. doi: 10.2105/AJPH.2012.301097. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Clark W, Bracken H, Tanenhaus J, Schweikert S, Lichtenberg ES, Winikoff B. Alternatives to a routine follow-up visit for early medical abortion. Obstet Gynecol. 2010;115:264–72. doi: 10.1097/AOG.0b013e3181c996f3. [DOI] [PubMed] [Google Scholar]
- 16.Horning EL, Chen BA, Meyn LA, Creinin MD. Comparison of medical abortion follow-up with serum human chorionic gonadotropin testing and in-office assessment. Contraception. 2012;85:402–7. doi: 10.1016/j.contraception.2011.09.007. [DOI] [PubMed] [Google Scholar]
- 17.Haimov-Kochman R, Arbel R, Sciaky-Tamir Y, Brzezinski A, Laufer N, Yagel S. Risk factors for unsuccessful medical abortion with mifepristone and misoprostol. Acta Obstet Gynecol Scand. 2007;86:462–6. doi: 10.1080/00016340701203632. [DOI] [PubMed] [Google Scholar]