Clinical research / standards

Given the available data and other considerations, both surgical and induction methods are safe and effective options for later abortion. The choice depends mainly upon patient preference and the availability of a clinician with the skills and experience to provide one or both approaches. Surgical abortion is recommended for those who prefer a procedure with greater control over timing and less experience of the procedure and who are willing to accept a higher risk of additional surgical intervention for complications. Induction (medication) abortion is recommended for women who place a high value on avoiding surgery or have a reason to prefer an intact fetus and who are willing to accept more discomfort and awareness during the procedure and a higher blood loss. Later surgical abortion is typically performed in an outpatient setting, either a specialty women’s health clinic, physician’s office equipped with a procedure room, or an ambulatory surgery center. Medical induction most commonly occurs in hospitals on a labor and delivery unit or a family planning unit within the hospital. Induction procedures can be performed in outpatient settings, with the appropriate medical staff and equipment to provide ongoing administration of induction agents, analgesia and anesthesia, monitoring of patient status, delivery of the fetus and placenta (timing is often unpredictable), and, if needed, emergency surgical management (in case of a need for immediate evacuation of either fetus or placenta) or emergency transport to an inpatient facility. An overview of clinical research and recommendations on both procedures is provided below.

Surgical termination

Surgical abortion, referred to as dilation and evacuation (D&E), accounts for the majority of later abortions in the United States [1-15]. The United States Centers for Disease Control and Prevention (CDC) reported that, in 2009, uterine curettage was used in 96 to 98 percent of abortions at 14 to 17 weeks of gestation, 95 percent at 18 to 20 weeks, and 91 percent at ≥21 weeks [3]. Both surgical and induction abortion in the second trimester are safe and effective, but surgical abortion is preferred by most women and access to induction abortion is limited due to a lack of skilled clinicians and facilities [16-18]. In addition, approximately 8% of women who undergo induction abortion require a surgical procedure for retained placenta. The typical protocol for surgical termination is outlined below:

  1. Cervical preparation. Dilation of the cervix is required prior to D&E to allow insertion of instruments and evacuation of the uterus. Cervical dilation is typically achieved in two phases: preprocedure cervical preparation with osmotic dilators and/orprostaglandins followed by mechanical dilation with surgical dilators on the day of the procedure. Cervical preparation and dilation is started up to two days prior to the procedure using an osmotic (eg, Dilapan) or pharmacologic (eg, misoprostol) dilator to dilate and soften the cervix. If further cervical dilation is needed, this is performed with mechanical dilators (eg, Pratt, Hegar) just prior to the procedure. Osmotic dilators appear to be more effective than pharmacologic methods [24-32]. The disadvantage of osmotic dilators is that they must be placed at least a day prior to the procedure, and often are placed over two days prior to the procedure, although same day options are available [25]. In contrast, misoprostol can be given the same day as the procedure, allowing for the procedure to be completed in one day. This decreases the expense of second trimester abortion and increases access for many patients.
  2. Injection to induce fetal demise. Injection of a substance to cause fetal demise prior to second trimester surgical abortion is controversial [33-36]. The advantages of this practice are that feticidal injection precludes the possibility of live birth, thereby potentially reducing emotional stress on the patient, and also allowing the surgeon to comply with legislation that penalizes uterine evacuation in which portions of the fetus are extracted prior to demise [33]. In addition, it has been proposed that fetal demise makes the procedure technically easier by inducing fetal maceration and cervical priming. Many clinicians use such injections before all second trimester surgical abortions, while others use them only in those cases in which they consider this to have a benefit for the patient.
  3. Cervical dilation. Based upon the diameter of most forceps used for D&E, the minimum dilation requires ranges from 14 to 19 mm [31]. Sufficient cervical dilation decreases the risk of morbidity, including cervical injury and uterine perforation [9, 13, 39]. Cervical preparation with osmotic dilators and/or prostaglandins accomplishes some of this dilation. Further dilation with surgical dilators is typically required. Additional dilation may also be required to remove the products of conception in advanced gestations.
  4. Uterine evacuation. The D&E procedure for evacuation of the fetus and placenta is performed using a combination of suction, extraction with forceps, and curettage [40-43]. After adequate cervical dilation is achieved, suction curettage is performed. Both the fetus and placenta must be entirely removed.  A variant of D&E is intact D&E, also referred to as D&X. With this technique, the fetus is removed intact or nearly intact through the cervix [44-46]. The potential advantages of D&X compared with standard D&E include [47]: (1) The likelihood of uterine perforation and cervical abrasion may be decreased because the technique minimizes the number of instrumental passes and permits direct visualization within the vagina; (2) Because the fetus is removed intact, it might also permit superior morphologic evaluation to further clarify prenatal diagnosis, although pathologic evaluation can also be performed on non-intact specimens [46]. In the United States, the Partial-Birth Abortion Act of 2003 criminalizes some variants of D&E and provides no legal exception for cases performed to protect maternal health. Physicians should consult the provisions of the law if they intend to perform an intact extraction, and some experts advise use of preoperative feticidal injection.
  5. Follow up. Many clinicians schedule a follow-up visit at two weeks, although most complications present before this time period. In settings where patients live a long distance from abortion facilities, it is appropriate to schedule follow-up with another clinician, to offer routine phone follow-up 24 to 48 hours afterwards, or to offer patient follow-up on an as-needed basis [47]. The patient should be given detailed instructions regarding signs and symptoms of complications. 

Medication (Induction) termination

Current protocols for later abortion typically include a prostaglandin (PG), usually misoprostol, and may utilize mifepristone or oxytocin [48-50]. A preoperative evaluation must first be performed prior to a later abortion to determine gestational age, general medical status, and any health factors that may impact the choice of medical versus surgical abortion. This involves: (1) Cervical preparation — Clinicians typically began induction termination by placing osmotic dilators in the cervix to facilitate induction through cervical ripening. This assures sufficient cervical dilation for surgical abortion if medical abortion fails or becomes excessively prolonged. This is especially true in patients with comorbidities whose medical condition may worsen and thus necessitate an expedited procedure; (2) Induced fetal demise — Clinicians induce demise prior to abortion either to facilitate the abortion procedure or to prevent live birth. Induction of demise prior to medical abortion might shorten induction to abortion interval, particularly if potassium chloride is utilized [48]; (3) Anesthesia — Women undergoing medical induction can receive anesthesia similar to that used for obstetric labor induction. Intermittent narcotic administration suffices for some patients, while others desire epidural anesthesia since this completely eliminates pain during more prolonged inductions.

Patients desiring medical abortion in later gestational age have safer, effective options, utilizing PG agents either alone or in combination with progesterone antagonists. The most common medications currently used for induction abortion are gemeprost and misoprostol. Studies find that both misoprostol and gemeprost induce labor more effectively and with fewer side effects than other PGs and than single-agent oxytocin or oxytocin in combination with other types of prostaglandins [49-53]. Misoprostol and gemeprost induce labor at a variety of gestational ages [54-55]. Misoprostol is typically the preferred agent due to lower rates of certain adverse effects and complications and based on practical considerations. Gemeprost and misoprostol have been found to have similar efficacy in randomized trials [54-62].

Mifepristone may be used in combination with misoprostol to decrease the induction-to-abortion interval and minimize pain [63-67]. Mifepristone elicits a variety of effects that make the uterus more susceptible to abortion. These effects include cervical dilation, decidual necrosis, increased endogenous prostaglandin production, and increasing uterine sensitivity to prostaglandin [63]. The World Health Organization (WHO), American College of Obstetricians and Gynecologists (ACOG), Society of Family Planning, and the United Kingdom Royal College of Obstetricians and Gynaecologists (RCOG) recommend regimens in which mifepristone precedes use of either misoprostol or gemeprost [66,68-70]

Advantages and disadvantages of surgical versus medical termination

Advantages of later surgical abortion include: (1) decreased procedure duration and predictable timing – Although patients usually undergo one to two days of cervical preparation, experienced surgeons can perform uterine evacuation in less than 30 minutes once the cervix is dilated. Labor induction, by contrast, may take as long as 24 hours or longer; (2) decreased cost – D&E usually occurs in an outpatient facility. Medical induction often requires admission to a higher cost labor and delivery unit [18]. (3) Medical conditions that required controlled timing of the procedure – The controlled timing of D&E permits planned procedures for patients whose medical conditions may worsen peripartum. Patients with bleeding diatheses, cardiac, and other maternal conditions often benefit from scheduled surgical procedures rather than less predictable induction procedures. Patients with multiple prior uterine surgeries and placenta previa can also undergo safe D&E, avoiding risks of uterine rupture or hemorrhage. Surgical abortion, however, has an elevated risk of uterine perforation compared with medical abortion – uterine perforation is a potential risk of surgical abortion and requires further surgical intervention.

Advantages of later medical abortion include an intact fetus – some patients choose labor induction to avoid fetal dismemberment associated with D&E. This may be due to a desire to hold the fetus or to provide an intact fetus for morphologic evaluation (this may be important when congenital anomalies are present). Disadvantages of later medical abortion include: (1) increased experience of the procedure – In induction abortion, the patient experiences uncomfortable effects (bleeding, cramping, nausea, vomiting) and these occur over a longer period of time during and after the procedure than with surgical abortion [16]. The patient also has a greater awareness of the process of terminating the pregnancy. Many patients find that the predictability of surgical abortion and avoiding the memory of prolonged labor make D&E less emotionally burdensome than induction abortion [19-21]; (2) unpredictability of the timing of delivery; (3) risk of hemorrhage or infection – Second trimester induction abortion is associated with higher blood loss than surgical abortion.


[Adapted from Hammond, C. Second trimester pregnancy termination. In: UpToDate, Steinauer, J (Ed), UpToDate, Waltham, MA. (Accessed on August 26, 2015.)]

For additional clinical research and standards for later abortion provision, see the Related Research in our archive.


  1. ACOG Practice Bulletin No. 135: Second-trimester abortion. Obstet Gynecol 2013; 121:1394
  2. Sedgh G, Henshaw S, Singh S, et al. Induced abortion: estimated rates and trends worldwide. Lancet 2007; 370:1338
  3. Pazol K, Creanga AA, Zane SB, et al. Abortion surveillance--United States, 2009. MMWR Surveill Summ 2012; 61:1
  4. Henshaw SK, Finer LB. The accessibility of abortion services in the United States, 2001. Perspect Sex Reprod Health 2003; 35:16
  5. Pazol K, Zane SB, Parker WY, et al. Abortion surveillance--United States, 2008. MMWR Surveill Summ 2011; 60:1
  6. Bartlett LA, Berg CJ, Shulman HB, et al. Risk factors for legal induced abortion-related mortality in the United States. Obstet Gynecol 2004; 103:729
  7. Drey EA, Foster DG, Jackson RA, et al. Risk factors associated with presenting for abortion in the second trimester. Obstet Gynecol 2006; 107:128
  8. Stubblefield PG, Carr-Ellis S, Borgatta L. Methods for induced abortion. Obstet Gynecol 2004; 104:174
  9. Grimes DA, Schulz KF, Cates WJ Jr. Prevention of uterine perforation during curettage abortion. JAMA 1984; 251:2108
  10. Kafrissen ME, Schulz KF, Grimes DA, Cates W Jr. Midtrimester abortion. Intra-amniotic instillation of hyperosmolar urea and prostaglandin F2 alpha v dilatation and evacuation. JAMA 1984; 251:916
  11. Grimes DA, Schulz KF, Cates W Jr, Tyler CW Jr. Mid-trimester abortion by dilatation and evacuation: a safe and practical alternative. N Engl J Med 1977; 296:1141
  12. Hern WM. Serial multiple laminaria and adjunctive urea in late outpatient dilatation and evacuation abortion. Obstet Gynecol 1984; 63:543
  13. Peterson WF, Berry FN, Grace MR, Gulbranson CL. Second-trimester abortion by dilatation and evacuation: an analysis of 11,747 cases. Obstet Gynecol 1983; 62:185
  14. Strauss LT, Gamble SB, Parker WY, et al. Abortion surveillance--United States, 2004. MMWR Surveill Summ 2007; 56:1
  15. Tietze C, Henshaw SK. Induced abortion: a world review, 3rd ed, Alan Guttmacher Institute, New York. 1986
  16. Kelly T, Suddes J, Howel D, et al. Comparing medical versus surgical termination of pregnancy at 13-20 weeks of gestation: a randomised controlled trial. BJOG 2010; 117:1512
  17. Grimes DA, Smith MS, Witham AD. Mifepristone and misoprostol versus dilation and evacuation for midtrimester abortion: a pilot randomised controlled trial. BJOG 2004; 111:148
  18. Cowett AA, Golub RM, Grobman WA. Cost-effectiveness of dilation and evacuation versus the induction of labor for second-trimester pregnancy termination. Am J Obstet Gynecol 2006; 194:768
  19. Freeman EW. Abortion: subjective attitudes and feelings. Fam Plann Perspect 1978; 10:150
  20. Rooks JB, Cates W Jr. Abortion methods: morbidity, costs and emotional impact. 3. Emotional impact of D&E vs. instillation. Fam Plann Perspect 1977; 9:276
  21. Kaltreider NB, Goldsmith S, Margolis AJ. The impact of midtrimester abortion techniques on patients and staff. Am J Obstet Gynecol 1979; 135:235
  22. Clinical Policy Guidelines of the National Abortion Federation, 2013 (Accessed on June 03, 2013)
  23. Prager SW, Oyer DJ. Second-trimester surgical abortion. Clin Obstet Gynecol 2009; 52:179
  24. Newmann SJ, Dalve-Endres A, Diedrich JT, et al. Cervical preparation for second trimester dilation and evacuation. Cochrane Database Syst Rev 2010; :CD007310
  25. Newmann SJ, Sokoloff A, Tharyil M, et al. Same-day synthetic osmotic dilators compared with overnight laminaria before abortion at 14-18 weeks of gestation: a randomized controlled trial. Obstet Gynecol 2014; 123:271
  26. Edelman AB, Buckmaster JG, Goetsch MF, et al. Cervical preparation using laminaria with adjunctive buccal misoprostol before second-trimester dilation and evacuation procedures: a randomized clinical trial. Am J Obstet Gynecol 2006; 194:425
  27. Darney PD, Dorward K. Cervical dilation before first-trimester elective abortion: a controlled comparison of meteneprost, laminaria, and hypan. Obstet Gynecol 1987; 70:397
  28. Chen JK, Elder MG. Preoperative cervical dilatation by vaginal pessaries containing prostaglandin E1 analogue. Obstet Gynecol 1983; 62:339
  29. Lauersen NH, Den T, Iliescu C, et al. Cervical priming prior to dilatation and evacuation: a comparison of methods. Am J Obstet Gynecol 1982; 144:890
  30. Carbonell JL, Gallego FG, Llorente MP, et al. Vaginal vs. sublingual misoprostol with mifepristone for cervical priming in second-trimester abortion by dilation and evacuation: a randomized clinical trial. Contraception 2007; 75:230
  31. Fox MC, Hayes JL, Society of Family Planning. Cervical preparation for second-trimester surgical abortion prior to 20 weeks of gestation. Contraception 2007; 76:486
  32. Newmann S, Dalve-Endres A, Drey EA, Society of Family Planning. Clinical guidelines. Cervical preparation for surgical abortion from 20 to 24 weeks' gestation. Contraception 2008; 77:308
  33. Grimes DA, Stuart GS, Raymond EG. Feticidal digoxin injection before dilation and evacuation abortion: evidence and ethics. Contraception 2012; 85:140
  34. Steward R, Melamed A, Kim R, et al. Infection and extramural delivery with use of digoxin as a feticidal agent. Contraception 2012; 85:150
  35. Dean G, Colarossi L, Lunde B, et al. Safety of digoxin for fetal demise before second-trimester abortion by dilation and evacuation. Contraception 2012; 85:144
  36. Diedrich J, Drey E, Society of Family Planning. Induction of fetal demise before abortion. Contraception 2010; 81:462
  37. ACOG Committee on Practice Bulletins--Gynecology. ACOG practice bulletin No. 104: antibiotic prophylaxis for gynecologic procedures. Obstet Gynecol 2009; 113:1180
  38. (Accessed on July 08, 2013)
  39. Schulz KF, Grimes DA, Cates W Jr. Measures to prevent cervical injury during suction curettage abortion. Lancet 1983; 1:1182
  40. Darney PD, Sweet RL. Routine intraoperative ultrasonography for second trimester abortion reduces incidence of uterine perforation. J Ultrasound Med 1989; 8:71
  41. Hammond C, Chasen S. Dilation and evacuation. In: Management of Unintended and Abnormal Pregnancy: Comprehensive Abortion Care, Paul M, Lichtenberg S, Borgatta L, et al (Eds) (Eds), Wiley-Blackwell, Oxford 2003. p.167
  42. Forna F, Gülmezoglu AM. Surgical procedures to evacuate incomplete abortion. Cochrane Database Syst Rev 2001; CD001993
  43. Lindell G, Flam F. Management of uterine perforations in connection with legal abortions. Acta Obstet Gynecol Scand 1995; 74:373
  44. McMahon JT. Intact D&E. The first decade. Presented at the National Abortion Federation conference. April, 1995
  45. Haskell M. Dilation and Extraction for Late Second Trimester Abortion. Presented at the National Abortion Federation Risk Management Seminar. September, 1992
  46. Gawron LM, Hammond C, Ernst LM. Perinatal pathologic examination of nonintact, second-trimester fetal demise specimens: the value of standardization. Arch Pathol Lab Med 2013; 137:1083
  47. Espey E, MacIsaac L. Management of Unintended and Abnormal Pregnancy: Comprehensive Abortion Care, Paul M, Lichtenberg S, Borgatta L, et al. (Eds), Wiley-Blackwell, Oxford, London 2003. p.211
  48. Elimian A, Verma U, Tejani N. Effect of causing fetal cardiac asystole on second-trimester abortion. Obstet Gynecol 1999; 94:139
  49. Hammond C. Recent advances in second-trimester abortion: an evidence-based review. Am J Obstet Gynecol 2009; 200:347
  50. Owen J, Hauth JC. Vaginal misoprostol vs. concentrated oxytocin plus low-dose prostaglandin E2 for second trimester pregnancy termination. J Matern Fetal Med 1999; 8:48
  51. Andersen LF, Poulsen HK, Sørensen SS, et al. Termination of second trimester pregnancy with gemeprost vaginal pessaries and intra-amniotic PGF2 alpha. A comparative study. Eur J Obstet Gynecol Reprod Biol 1989; 31:1
  52. Cameron IT, Baird DT. The use of 16,16-dimethyl-trans delta 2 prostaglandin E1 methyl ester (gemeprost) vaginal pessaries for the termination of pregnancy in the early second trimester. A comparison with extra-amniotic prostaglandin E2. Br J Obstet Gynaecol 1984; 91:1136
  53. Su LL, Biswas A, Choolani M, et al. A prospective, randomized comparison of vaginal misoprostol versus intra-amniotic prostaglandins for midtrimester termination of pregnancy. Am J Obstet Gynecol 2005; 193:1410
  54. Blanchard K, Clark S, Winikoff B, et al. Misoprostol for women's health: a review. Obstet Gynecol 2002; 99:316
  55. Nor Azlin MI, Abdullah HS, Zainul Rashid MR, Jamil MA. Misoprostol (alone) in second trimester terminations of pregnancy: as effective as Gemeprost? J Obstet Gynaecol 2006; 26:546
  56. Nuutila M, Toivonen J, Ylikorkala O, Halmesmäki E. A comparison between two doses of intravaginal misoprostol and gemeprost for induction of second-trimester abortion. Obstet Gynecol 1997; 90:896
  57. Wong KS, Ngai CS, Wong AY, et al. Vaginal misoprostol compared with vaginal gemeprost in termination of second trimester pregnancy. A randomized trial. Contraception 1998; 58:207
  58. Dodd JM, Crowther CA. Misoprostol versus cervagem for the induction of labour to terminate pregnancy in the second and third trimester: a systematic review. Eur J Obstet Gynecol Reprod Biol 2006; 125:3
  59. Wildschut H, Both MI, Medema S, et al. Medical methods for mid-trimester termination of pregnancy. Cochrane Database Syst Rev 2011; :CD005216
  60. Ashok PW, Templeton A, Wagaarachchi PT, Flett GM. Midtrimester medical termination of pregnancy: a review of 1002 consecutive cases. Contraception 2004; 69:51
  61. Wong KS, Ngai CS, Yeo EL, et al. A comparison of two regimens of intravaginal misoprostol for termination of second trimester pregnancy: a randomized comparative trial. Hum Reprod 2000; 15:709
  62. Pongsatha S, Tongsong T. Intravaginal misoprostol for pregnancy termination. Int J Gynaecol Obstet 2004; 87:176
  63. Bygdeman M, Swahn ML. Progesterone receptor blockage. Effect on uterine contractility and early pregnancy. Contraception 1985; 32:45
  64. Tang OS, Chan CC, Kan AS, Ho PC. A prospective randomized comparison of sublingual and oral misoprostol when combined with mifepristone for medical abortion at 12-20 weeks gestation. Hum Reprod 2005; 20:3062
  65. Kapp N, Borgatta L, Stubblefield P, et al. Mifepristone in second-trimester medical abortion: a randomized controlled trial. Obstet Gynecol 2007; 110:1304
  66. Borgatta L, Kapp N, Society of Family Planning. Clinical guidelines. Labor induction abortion in the second trimester. Contraception 2011; 84:4
  67. Ngoc NT, Shochet T, Raghavan S, et al. Mifepristone and misoprostol compared with misoprostol alone for second-trimester abortion: a randomized controlled trial. Obstet Gynecol 2011; 118:601
  68. ACOG Practice Bulletin No. 135: Second-trimester abortion. Obstet Gynecol 2013; 121:1394
Subscribe to RSS - Clinical research / standards