Dear editor
We read the recent review article entitled “Prevention of preterm delivery: current challenges and future prospects” by van Zijl et al.1 However, they did not adequately discuss the prevention of preterm delivery in cases with a history of conization, or a cone biopsy of the uterine cervix.2,3 Performing a cervical cerclage has been common in the treatment of pregnant women with cervical insufficiency to prevent preterm delivery, as reported by van Zijl et al.1 However, the effect of prophylactic cerclage in women with a history of conization is little understood, because there are no prospective randomized controlled trials concerning the efficiency and risk of prophylactic cerclage in this subgroup of pregnant women.3–15 Table 1 summarizes the previous examinations concerning the effect of prophylactic cerclage in pregnancy after conization, including four English language articles searched using PubMed (Bethesda, MD, USA) and eight Japanese language articles searched using Igaku Chuo Zasshi® (NPO Japan Medical Abstracts society, Tokyo, Japan), with the key search terms of “cerclage” and “conization”.4–15 In these studies, statistical significances of the categorical variables were tested by χ2 test (with Yates’s correction) or Fisher’s exact test. As shown in Table 1, there have been some small retrospective population-based cohort studies in this field. In an earlier study,3 cerclage has been recommended in pregnancies following excessive cone biopsy. However, some recent studies have suggested an association between local infection in cases of short cervices related to large cones and preterm labor in women with a history of conization.4–7 In these cases, sutures can act as a foreign body and lead to uterine irritability and contractions after a cerclage procedure.5–7 Moreover, some authors have reported a significant increase in pathologic flora in the vagina and cervix after cerclage leading to chorioamnionitis and preterm labor.16 Thus, prophylactic cerclage is used more sparingly in pregnancies following conization in recent years.5–7
Table 1.
Preterm delivery rate (%) with pregnancies after cervical conization with and without prophylactic cerclage in four English and eight Japanese retrospective population-based cohort studies
| Preterm delivery/abortion | Prophylactic cerclage
|
P-value | ||
|---|---|---|---|---|
| Yes | No | |||
| English literature | ||||
| Zeisler et al,4 1997 | <37 weeks | 23% (7/30) | 21% (8/39) | 0.78 |
| Nam et al,5 2010 | <37 weeks | 50% (3/6) | 25% (15/59) | 0.42 |
| Shin et al,6 2010 | <28 weeks | 8% (2/25) | 7% (2/31) | 0.58 |
| <34 weeks | 20% (5/25) | 19% (6/31) | 1.00 | |
| <37 weeks | 36% (9/25) | 29% (9/31) | 1.00 | |
| <37 weeks | 25% (3/12) | 43% (3/7) | 0.62 | |
| (CL <25 mm) | ||||
| Rafaeli-Yehudai et al,7 2014 | <34 weeks | 32% (7/22) | 6% (5/97) | 0.02 |
| Japanese literature | ||||
| Nagasaka et al,8 2002 | <37 weeks | 60% (3/5) | 13% (1/8) | 0.24 |
| Matsui et al,9 2008 | <37 weeks | 30% (3/10) | 30% (6/20) | 1.00 |
| Tokunaka et al,10 2010 | <37 weeks | Unknown (n=8) | Unknown (n=21) | NS |
| Muro et al,11 2013 | <34 weeks | 6% (2/35) | 25% (3/12) | 0.06 |
| <37 weeks | 20% (7/35) | 42% (5/12) | 0.14 | |
| <34 weeks | 0% (0/13) | 100% (3/3) | <0.01 | |
| (CL <25 mm) | ||||
| <37 weeks | 23% (3/13) | 67% (2/3) | 0.44 | |
| (CL <25 mm) | ||||
| Tanimoto et al,12 2013 | <37 weeks | 36% (4/11) | 30% (14/47) | 0.82 |
| Ishiguro et al,13 2013 | <37 weeks | 19% (4/21) | – | – |
| <37 weeks | 50% (4/8) | – | – | |
| (CL <25 mm) | ||||
| Kawasaki et al,14 2013 | <37 weeks | 17% (1/6) | 12% (7/58) | 0.75 |
| Kawana et al,15 2015 | <33 weeks | – | 4% (5/68) | – |
| <37 weeks | – | 18% (12/68) | – | |
Abbreviations: NS, not significant; CL, cervical length.
Between 2011 and 2015, 62 cases of pregnancy with a history of conization were managed at the Japanese Red Cross Katsushika Maternity Hospital. During this period, I had not performed cerclage in any cases of pregnancy with a history of conization irrespective of the cervical length. Of the 62 cases, nine cases (15%) resulted in miscarriage or preterm delivery (18%). In eight (89%) of the nine cases, chorioamnionitis of the placenta was confirmed microscopically. My cases may support the latter studies,4–7 suggesting an association between infection and preterm labor in women with a history of conization.
A therapeutic dilemma exists among patients with short cervix in pregnancy after conization.
Footnotes
Disclosure
The author reports no conflicts of interest in this communication.
References
- 1.van Zijl MD, Koullali B, Mol BW, Pajkrt E, Oudijk MA. Prevention of preterm delivery: current challenges and future prospects. Int J Womens Health. 2016;8:633–645. doi: 10.2147/IJWH.S89317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Armarnik S, Sheiner E, Piura B, Meirovitz M, Zlotnik A, Levy A. Obstetric outcome following cervical conization. Arch Gynecol Obstet. 2011;283(4):765–769. doi: 10.1007/s00404-011-1848-3. [DOI] [PubMed] [Google Scholar]
- 3.Leiman G, Harrison NA, Rubin A. Pregnancy following conization of the cervix: complications related to cone size. Am J Obstet Gynecol. 1980;136(1):14–18. doi: 10.1016/0002-9378(80)90556-6. [DOI] [PubMed] [Google Scholar]
- 4.Zeisler H, Joura EA, Bancher-Todesca D, Hanzal E, Gitsch G. Prophylactic cerclage in pregnancy. Effect in women with a history of conization. J Reprod Med. 1997;42(7):390–392. [PubMed] [Google Scholar]
- 5.Nam KH, Kwon JY, Kim YH, Park YW. Pregnancy outcome after cervical conization: risk factors for preterm delivery and the efficacy of prophylactic cerclage. J Gynecol Oncol. 2010;21(4):225–229. doi: 10.3802/jgo.2010.21.4.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Shin MY, Seo ES, Choi SJ, et al. The role of prophylactic cerclage in preventing preterm delivery after electrosurgical conization. J Gynecol Oncol. 2010;21(4):230–236. doi: 10.3802/jgo.2010.21.4.230. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Rafaeli-Yehudai T, Kessous R, Aricha-Tamir B, et al. The effect of cervical cerclage on pregnancy outcomes in women following conization. J Matern Fetal Neonatal Med. 2014;27(15):1594–1597. doi: 10.3109/14767058.2013.871254. [DOI] [PubMed] [Google Scholar]
- 8.Nagasaka I, Takamoto M, Saito M, et al. Outcomes of cervical cerclage in pregnancy after conization. Kanto J Obstet Gynecol. 2002;39(2):175. Japanese. [Google Scholar]
- 9.Matsui T, Usui R, Okuchi A, et al. Preterm delivery rate in pregnancy after conization in a cohort study. J Jpn Soc Perin Meon Med. 2008;43(2):461. Japanese. [Google Scholar]
- 10.Tokunaka M, Otsuki K, Matsuura R, et al. Management of pregnancy after conization. Acta Obstet Gynaecol Jpn. 2010;62(2):643. Japanese. [Google Scholar]
- 11.Muro M, Nakahashi H, Tanaka T, Noguchi M, Tsumura K, Yokoyama M. The effect of cervical cerclage in pregnancy after conization. Obstet Gynecol Pract. 2013;62(3):417–423. Japanese. [Google Scholar]
- 12.Tanimoto H, Okamoto K, Takao Y, Honda H, Teramoto M, Teramoto H. Obstetric outcomes in pregnancy after conization. Clin Gynecol Obstet. 2013;67(1):193–196. Japanese. [Google Scholar]
- 13.Ishiguro H, Kurabayashi T, Tominaga M, et al. Clinical examination of cervical cerclage after cervical conization. J Niigata City Hospital. 2013;34(1):8–12. Japanese. [Google Scholar]
- 14.Kawasaki A, Kurioka H, Miyamoto J, et al. Obstetric outcomes following cervical conization. Mod Trends Obstet Gynecol. 2013;62(1):117–121. Japanese. [Google Scholar]
- 15.Kawana Y, Adachi T, Nakabayashi Y, et al. Outcomes in pregnancy after conization without cervical cerclage. Obstet Gynaecol Jpn. 2015;67(2):961. [Google Scholar]
- 16.Charles D, Edwards WR. Infectious complications of cervical cerclage. Am J Obstet Gynecol. 1981;141(8):1065–1071. doi: 10.1016/s0002-9378(16)32698-9. [DOI] [PubMed] [Google Scholar]