Download PDF
Am J Perinatol 2024; 41(S 01): e818-e826
DOI: 10.1055/a-1948-2779
Original Article

Labor Induction Outcomes with Outpatient Misoprostol for Cervical Ripening among Low-Risk Women

Nazineen Kandahari
1   School of Medicine, University of California San Francisco, San Francisco, California
3   Division of Research, Kaiser Permanente, Oakland, California
4   Department of Obstetrics and Gynecology, Kaiser Permanente Northern California, Walnut Creek, California
,
Allison N. Schneider
2   Department of Obstetrics and Gynecology, George Washington University Medical Faculty Associates, Washington, District of Columbia
,
Lue-Yen S. Tucker
3   Division of Research, Kaiser Permanente, Oakland, California
,
Tina R. Raine-Bennett
3   Division of Research, Kaiser Permanente, Oakland, California
4   Department of Obstetrics and Gynecology, Kaiser Permanente Northern California, Walnut Creek, California
,
Vanitha J. Mohta
4   Department of Obstetrics and Gynecology, Kaiser Permanente Northern California, Walnut Creek, California
› Author Affiliations
Funding This project was approved by the Kaiser Permanente Northern California Institutional Review Board with a specified waiver of consent for a data-only descriptive study and was funded by the KPNC Graduate Medical Education, Kaiser Foundation Hospitals.
› Further Information
Also available at
   Permissions and Reprints

Abstract

Objective In 2012, two Kaiser Permanente Northern California (KPNC) hospitals began offering outpatient cervical ripening with oral misoprostol under a study protocol. We evaluated inpatient time from admission to delivery and adverse maternal and neonatal outcomes associated with outpatient use of misoprostol for cervical ripening among low-risk women with term pregnancies.

Study Design We conducted a retrospective cohort study comparing three groups: women who received misoprostol (1) outpatient, under a study protocol; (2) inpatient, at the study sites; and (3) inpatient, at all KPNC hospitals. Data were obtained from between 2012 and 2017. The primary outcome was time from inpatient admission to delivery. Secondarily, we evaluated maternal and neonatal outcomes, including the duration and maximum rate of oxytocin administered, rate of cesarean delivery, incidence of chorioamnionitis and blood transfusion, Apgar scores, and neonatal intensive care unit admissions. Demographic and clinical characteristics and outcomes of the outpatient group were compared with both inpatient misoprostol groups using the appropriate statistical test. Variables included in the regression analysis were either statistically significant in the bivariate analyses or have been reported in the literature to be potential confounders: maternal age at admission, race/ethnicity, body mass index, cervical dilation at initial misoprostol, and parity.

Results We analyzed data from 10,253 patients: (1) 345 outpatients, under a study protocol; (2) 1,374 inpatients, at the study sites; and (3) 9,908 inpatients, at all the Kaiser hospitals. Women in the outpatient group were more likely to be white than both inpatient groups (63.3 vs. 56.3% at study sites and 47.1% in all hospitals, p = 0.002 and <0.001, respectively); other demographics were clinically comparable. Most women undergoing labor induction were nulliparous; however, a greater proportion in the outpatient group were nulliparous compared with inpatient groups (70.8 vs. 61.8% and 64.3%, p = 0.002 and 0.01). On inpatient admission for delivery, women who received outpatient misoprostol were more likely to have a cervical dilation of ≥3 cm (39.8 vs. 12.5% at study sites and 9.7% at all KPNC hospitals, p < 0.001 for both). The outpatient group had a shorter mean time between admission and delivery (23.6 vs. 29.4 at study sites and 29.8 hours at all KPNC, p < 0.001 for both). The adjusted estimated mean difference between the outpatient and inpatient group at all the Kaiser hospitals in time from admission to delivery was −6.48 hours (p < 0.001), and the adjusted estimated mean difference in cervical dilation on admission was +1.02 cm (p < 0.001). There was no difference in cesarean delivery rates between groups. The rate of chorioamnionitis in the outpatient group was higher compared with inpatients at all hospitals (17.7 vs. 10.6%, p < 0.001), but similar when compared with the inpatients at the study sites (17.7 vs. 15.4%, p = 0.29).

Conclusion Outpatient use of misoprostol for cervical ripening under the study protocol was associated with reduced inpatient time from admission to delivery compared with inpatient misoprostol. Although there was a higher rate of chorioamnionitis among outpatients under the study protocol compared with inpatients at all hospitals, there was no difference when compared with inpatients at the study sites. There was no difference in rates of cesarean delivery or maternal or neonatal complications with outpatient misoprostol.

Key Points

  • Outpatient misoprostol patients had 6.46 fewer hours from admission to delivery compared with inpatients at all hospitals.

  • There was no difference in the rate of cesareans between the outpatient versus inpatient misoprostol groups.

  • Other maternal and neonatal complications were low and comparable among outpatients and inpatients who received misoprostol; this study was not large enough to assess rare safety outcomes.

Keywords

misoprostol - outpatient - cervical ripening - induction of labor - cesarean delivery - maternal complications - chorioamnionitis - neonatal complications - inpatient stay

Note

This study was presented the 69th Annual Clinical and Scientific Meeting, American College of Obstetricians and Gynecologists, Seattle, Washington, April 24–27, 2020.




Publication History

Received: 08 May 2022

Accepted: 14 September 2022

Accepted Manuscript online:
21 September 2022

Article published online:
15 November 2022

© 2022. Thieme. All rights reserved.

Thieme Medical Publishers, Inc.
333 Seventh Avenue, 18th Floor, New York, NY 10001, USA

 

  • References

  • 1 Martin JA, Hamilton BE, Osterman MJK, Driscoll AK. Births: Final Data for 2018. Natl Vital Stat Rep 2019; 68 (13) 1-47
    PubMedSearch in Google Scholar
  • 2 Grobman WA, Sandoval G, Reddy UM. et al; Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units (MFMU) Network. Health resource utilization of labor induction versus expectant management. Am J Obstet Gynecol 2020; 222 (04) 369.e1-369.e11
    CrossrefPubMedSearch in Google Scholar
  • 3 Carbone JF, Tuuli MG, Fogertey PJ, Roehl KA, Macones GA. Combination of Foley bulb and vaginal misoprostol compared with vaginal misoprostol alone for cervical ripening and labor induction: a randomized controlled trial. Obstet Gynecol 2013; 121 (2 Pt 1): 247-252
    CrossrefPubMedSearch in Google Scholar
  • 4 Hill JB, Thigpen BD, Bofill JA, Magann E, Moore LE, Martin Jr JN. A randomized clinical trial comparing vaginal misoprostol versus cervical Foley plus oral misoprostol for cervical ripening and labor induction. Am J Perinatol 2009; 26 (01) 33-38
    Thieme ConnectPubMedSearch in Google Scholar
  • 5 Chung JH, Huang WH, Rumney PJ, Garite TJ, Nageotte MP. A prospective randomized controlled trial that compared misoprostol, Foley catheter, and combination misoprostol—Foley catheter for labor induction. Am J Obstet Gynecol 2003; 189 (04) 1031-1035
    CrossrefPubMedSearch in Google Scholar
  • 6 Teixeira C, Lunet N, Rodrigues T, Barros H. The Bishop Score as a determinant of labour induction success: a systematic review and meta-analysis. Arch Gynecol Obstet 2012; 286 (03) 739-753
    CrossrefPubMedSearch in Google Scholar
  • 7 Allen R, O'Brien BM. Uses of misoprostol in obstetrics and gynecology. Rev Obstet Gynecol 2009; 2 (03) 159-168
    PubMedSearch in Google Scholar
  • 8 ACOG Committee on Practice Bulletins–Obstetrics. ACOG Practice Bulletin No. 107: induction of labor. Obstet Gynecol 2009; 114 (2, pt. 1): 386-397
    CrossrefPubMedSearch in Google Scholar
  • 9 Kipikasa JH, Adair CD, Williamson J, Breen JM, Medford LK, Sanchez-Ramos L. Use of misoprostol on an outpatient basis for postdate pregnancy. Int J Gynaecol Obstet 2005; 88 (02) 108-111
    CrossrefPubMedSearch in Google Scholar
  • 10 Gaffaney CAL, Saul LL, Rumney PJ. et al. Outpatient oral misoprostol for prolonged pregnancies: a pilot investigation. Am J Perinatol 2009; 26 (09) 673-677
    Thieme ConnectPubMedSearch in Google Scholar
  • 11 Stitely ML, Browning J, Fowler M, Gendron RT, Gherman RB. Outpatient cervical ripening with intravaginal misoprostol. Obstet Gynecol 2000; 96 (5, pt. 1): 684-688
    PubMedSearch in Google Scholar
  • 12 Meyer M, Pflum J, Howard D. Outpatient misoprostol compared with dinoprostone gel for preinduction cervical ripening: a randomized controlled trial. Obstet Gynecol 2005; 105 (03) 466-472
    CrossrefPubMedSearch in Google Scholar
  • 13 McDonagh M, Skelly AC, Hermesch A. et al. Cervical ripening in the outpatient setting. Agency for Healthcare Research and Quality (US); 2021. . Accessed June 15, 2022 at: http://www.ncbi.nlm.nih.gov/books/NBK569292/
    CrossrefSearch in Google Scholar
  • 14 Ausbeck EB, Jauk VC, Xue Y. et al. Outpatient foley catheter for induction of labor in nulliparous women: a randomized controlled trial. Obstet Gynecol 2020; 136 (03) 597-606
    CrossrefPubMedSearch in Google Scholar
  • 15 Stock SJ, Bhide A, Richardson H. et al. Cervical ripening at home or in-hospital-prospective cohort study and process evaluation (CHOICE) study: a protocol. BMJ Open 2021; 11 (05) e050452
    CrossrefPubMedSearch in Google Scholar
  • 16 Sharp AN, Stock SJ, Alfirevic Z. Outpatient induction of labour in the UK: a survey of practice. Eur J Obstet Gynecol Reprod Biol 2016; 204: 21-23
    CrossrefPubMedSearch in Google Scholar
  • 17 Chang DW, Velazquez MD, Colyer M, Klaus P, Mallipeddi SK, Rayburn WF. Vaginal misoprostol for cervical ripening at term: comparison of outpatient vs. inpatient administration. J Reprod Med 2005; 50 (10) 735-739
    PubMedSearch in Google Scholar
  • 18 Tita ATN, Andrews WW. Diagnosis and management of clinical chorioamnionitis. Clin Perinatol 2010; 37 (02) 339-354
    CrossrefPubMedSearch in Google Scholar
  • 19 Shetty A, Burt R, Rice P, Templeton A. Women's perceptions, expectations and satisfaction with induced labour—a questionnaire-based study. Eur J Obstet Gynecol Reprod Biol 2005; 123 (01) 56-61
    CrossrefPubMedSearch in Google Scholar
  • 20 Adelson PL, Wedlock GR, Wilkinson CS, Howard K, Bryce RL, Turnbull DA. A cost analysis of inpatient compared with outpatient prostaglandin E2 cervical priming for induction of labour: results from the OPRA trial. Aust Health Rev 2013; 37 (04) 467-473
    CrossrefPubMedSearch in Google Scholar
  • 21 Health (UK) NCC for W and C.. Setting and timing for induction of labour. RCOG Press; 2008. . Accessed April 17, 2020 at: https://www.ncbi.nlm.nih.gov/books/NBK53610/
    Search in Google Scholar
  • 22 Oboro VO, Tabowei TO. Outpatient misoprostol cervical ripening without subsequent induction of labor to prevent post-term pregnancy. Acta Obstet Gynecol Scand 2005; 84 (07) 628-631
    CrossrefPubMedSearch in Google Scholar
  • 23 McKenna DS, Ester JB, Proffitt M, Waddell KR. Misoprostol outpatient cervical ripening without subsequent induction of labor: a randomized trial. Obstet Gynecol 2004; 104 (03) 579-584
    CrossrefPubMedSearch in Google Scholar
  • 24 Wilkinson C, Bryce R, Adelson P, Turnbull D. A randomised controlled trial of outpatient compared with inpatient cervical ripening with prostaglandin E2 (OPRA study). BJOG 2015; 122 (01) 94-104
    CrossrefPubMedSearch in Google Scholar
  • 25 Wing DA, Rahall A, Jones MM, Goodwin TM, Paul RH. Misoprostol: an effective agent for cervical ripening and labor induction. Am J Obstet Gynecol 1995; 172 (06) 1811-1816
    CrossrefPubMedSearch in Google Scholar