Last reviewed: October 7, 2022
Recommendation:
- Cervical preparation is recommended after 12-14 weeks gestation. Before 12-14 weeks gestation, cervical preparation may be considered, but should not be routinely used.
- Recommended methods for cervical preparation include:
- Misoprostol 400mcg sublingually 1-3 hours before the procedure.
- Misoprostol 400mcg vaginally or buccally 3 hours before the procedure.
- Or mifepristone 200mg orally 1-2 days before the procedure.
Strength of recommendation: Strong
Quality of evidence: Moderate
Benefits of cervical preparation
A meta-analysis of 51 randomized controlled clinical trials of cervical preparation through 13 weeks gestation found that procedure time was shorter with cervical preparation but there were no differences in serious complications, such as cervical laceration or uterine perforation, in people given cervical preparation compared to those given placebo (Kapp et al., 2010). In the largest multicenter randomized controlled trial, which included 4,972 women given either misoprostol 400mcg vaginally or placebo three hours before a vacuum aspiration, there was no difference in the rates of cervical laceration, perforation or infection between the two groups (Meirik et al., 2012). However, a significant decrease in the risk of incomplete abortion was observed in those who received misoprostol for cervical preparation (<1%) compared to the placebo group (2%), but side effects were more frequent for those who were given misoprostol. For people at higher risk of complications during cervical dilation (young people, people with cervical abnormalities or prior cervical surgery) or for inexperienced providers, there may be a benefit from cervical preparation before 12-14 weeks gestation (Allen & Goldberg, 2016; Grimes, Schulz, & Cates, 1984; Kaunitz et al., 1985).
Side effects of cervical preparation
In the largest randomized controlled trial of misoprostol for cervical preparation, 55% of participants who took misoprostol complained of pre-procedure abdominal pain and 37% had vaginal bleeding, compared to 22% and 7% in the placebo group (Meirik et al., 2012). In addition, cervical preparation adds cost, complexity and time to an abortion, as individuals must visit the clinic a day before the procedure to receive mifepristone, or must wait in the health center for misoprostol to take effect. Because abortion before 13 weeks gestation is very safe, the gestational age at which the benefit of routine cervical preparation outweighs the side-effects is not known (Kapp et al., 2010). Patient’s satisfaction with cervical preparation has not been systematically studied in randomized controlled trials but is an important consideration for quality of care and service delivery (Kapp et al., 2010).
Choice of methods
The choice of misoprostol or mifepristone for cervical preparation depends on availability, expense, convenience and preference. Sublingual misoprostol has superior effectiveness but more gastrointestinal side effects than vaginal misoprostol (Kapp et al., 2010; Saav et al., 2015; Saxena et al., 2008). Mifepristone given 24 hours prior to the abortion results in greater cervical dilation and less aspiration associated pain than misoprostol, but adds time and expense to the abortion procedure (Ashok, Flett, & Templeton, 2000; Hmadaoui et al., 2021; Kapp et al., 2010). Misoprostol and osmotic dialators have similiar effectiveness, however the World Health Organization (WHO) recommends against the use of osmotic dilators for cervical priming before 12 weeks gestation due to the longer time to complete the procedure and reduced satisfaction among participants compared to misoprostol (Bartz, et al., 2013; Burnett, Corbett, & Gertenstein, 2005; MacIsaac et al., 1999; WHO, 2022).
Young people
Adolescents may benefit from cervical preparation due to their increased risk of cervical injury during abortion (Allen & Goldberg, 2016; Schulz et al., 1983). This risk is independent of nulliparity (Meirik et al., 2014); adolescents have physiologically immature cervices that may be more difficult to dilate regardless of obstetric history (Allen & Goldberg, 2016; Schulz et al., 1983). There are no clinical trials examining the use of cervical preparation in this patient population.
Who can perform cervical preparation with medications?
WHO makes service delivery recommendations for the provision of uterine aspiration, which includes assessment of gestational age, cervical preparation if needed, the procedure itself, pain management including the provision of a paracervical block, and the assessment of procedure completeness through visual examination of the products of conception (WHO, 2022). WHO advises that provision of medication for cervical preparation is within the scope of practice for specialty and general medical practitioners, and recommends the provision of cervical preparation medications by associate and advanced associate clinicians, midwives, nurses, auxiliary nurses and auxiliary nurse midwives, and traditional and complementary medicine professionals based on expected competencies for these roles and low-certainty evidence of safety and effectiveness. Although there is no direct evidence, WHO suggests that community health workers, pharmacists and pharmacy workers can safely and effectively provide medications for cervical preparation based on expected competencies for these roles, adding that these health workers need to ensure continuity of care for the individual obtaining the medications prior to an abortion procedure (WHO, 2022). For further information about health worker roles in abortion care, see Appendix C: World Health Organization recommendations for health worker roles in abortion care.
References
Allen, R., & Goldberg, A. (2016). Society of Family Planning Clinical Guideline 20071: Cervical dilation before first trimester surgical abortion (< 14 weeks gestation). Contraception, 93(4), 277-291.
Ashok, P. W., Flett, G. M., & Templeton, A. (2000). Mifepristone versus vaginally administered misoprostol for cervical priming before first-trimester termination of pregnancy: A randomized, controlled study. American Journal of Obstetrics & Gynecology, 183(4), 998-1002.
Bartz, D., Maurer, R., Allen, R., Fortin, J., Kuang, B., & Goldberg, A. (2013). Buccal misoprostol compared with synthetic osmotic cervical dilator before surgical abortion: A randomized controlled trial. Obstetrics & Gynecology, 122, 57-63.
Burnett, M. A., Corbett, C. A., & Gertenstein, R. J. (2005). A randomized trial of laminaria tents versus vaginal misoprostol for cervical ripening in first trimester surgical abortion. Journal of Obstetrics and Gynaecology Canada, 27(1), 38-42.
Grimes, D. A., Schulz, K. F., & Cates, W. J., Jr. (1984). Prevention of uterine perforation during curettage abortion. Journal of American Medical Association, 251(16), 2108-2111.
Hamdaoui, N., Cardinale, C., Fabre, C., Baumstarck, K., & Agostini, A. (2021). Pain associated with cervical priming for first-trimester surgical abortion: A randomized controlled trial. Obstetrics & Gynecology, 137(6), 1055-1060.
Kapp, N., Lohr, P. A., Ngo, T. D., & Hayes, J. L. (2010). Cervical preparation for first trimester surgical abortion. The Cochrane Database of Systematic Reviews (2), CD007207.
Kaunitz, A. M., Rovira, E. Z., Grimes, D. A., & Schulz, K. F. (1985). Abortions that fail. Obstetrics & Gynecology, 66(4), 533-537.
MacIsaac, L., Grossman, D., Balistreri, E., & Darney, P. (1999). A randomized controlled trial of laminaria, oral misoprostol, and vaginal misoprostol before abortion. Obstetrics & Gynecology, 93(5 Pt 1), 766-770.
Meirik, O., Huong, N. T., Piaggio, G., Bergel, E., & von Hertzen, H. (2012). Complications of first-trimester abortion by vacuum aspiration after cervical preparation with and without misoprostol: A multicentre randomised trial. The Lancet, 379(9828), 1817-1824.
O’Shea, L.E., Lord, J., Fletcher, J., Hasler, E., & Cameron, S. (2020). Cervical priming before surgical abortion up to 13+6 weeks’ gestation: A systematic review and metaanalyses for the National Institute for Health and Care Excellence-new clinical guidelines for England. American Journal of Obstetrics and Gynecology MFM, 2(4), 100220.
Saav, I., Kopp Kallner, H., Fiala, C., & Gemzell-Danielsson., K. (2015). Sublingual versus vaginal misoprostol for cervical dilatation 1 or 3 h prior to surgical abortion: A double blinded RCT. Human Reproduction, 30(6), 1314-1322.
Saxena P., Sarda, N., Salhan, S., & Nandan, D. (2008). A randomised comparison between sublingual, oral and vaginal route of misoprostol for pre-abortion cervical ripening in first-trimester pregnancy termination under local anesthesia. Australian and New Zealand Journal of Obstetrics and Gynaecology, 48(1), 101-6.
Schulz, K. F., Grimes, D. A., & Cates, W., Jr. (1983). Measures to prevent cervical injury during suction curettage abortion. The Lancet, 1(8335), 1182-1185.
World Health Organization. (2022). Abortion care guideline. Geneva: World Health Organization.