CIN Treatment May Increase Miscarriages but Does Not Affect Fertility


Am Fam Physician. 2015 Apr 1;91(7):490.

Clinical Question

What is the effect of treatment for cervical intraepithelial neoplasia (CIN) on fertility and early pregnancy outcomes?

Bottom Line

In this analysis of 15 observational studies (it would be difficult and unethical to do randomized research on this topic), excision using any method for CIN did not affect fertility, although second trimester miscarriages were more likely. A study published at the same time found the risk of preterm birth doubled with excisions of a depth of at least 15 mm. (Level of Evidence = 2a)


To conduct this meta-analysis, the authors used Medline and Embase to identify all studies that compared fertility and early pregnancy (< 24 weeks' gestation) outcomes in women with or without treatment for CIN. They included all types of treatment, both ablative and excisional. Two investigators independently performed the literature searches and data extraction. The authors included 15 cohort studies that used any method to assemble women who did and did not undergo treatment, and evaluated fertility and early pregnancy outcomes. Regardless of type of treatment, pregnancy rates or time to conception in women trying to conceive was not affected by treatment of CIN in four studies of 38,050 women. Total miscarriage rates also were not different in 10 studies of 39,504 women. However, second semester miscarriage rates were higher (1.6% vs. 0.4%) in women who underwent treatment (risk ratio = 2.60; 95% confidence interval, 1.45 to 4.67). The numbers of ectopic pregnancies (1.6% vs. 0.8%) and pregnancy terminations (12.2% vs. 7.4%) were also higher in treated women. In a separate case-control study that evaluated 1,313 women who underwent colposcopy with 1,313 matched control patients, the risk of preterm birth was not affected by a small excision, but larger lesions (15 mm or more) were associated with a doubling of the risk of preterm and very preterm births, independent of the time since the excision (BMJ. 2014;349:g6223).

Study design: Meta-analysis

Funding source: Government

Setting: Various (meta-analysis)

Reference: Kyrgiou M, Mitra A, Arbyn M, et al. Fertility and early pregnancy outcomes after treatment for cervical intraepithelial neoplasia: systematic review and meta-analysis. BMJ.. 2014; 349: g6192.

POEMs (patient-oriented evidence that matters) are provided by EssentialEvidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, please see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see http://www.essentialevidenceplus.com/product/ebm_loe.cfm?show=oxford.

To subscribe to a free podcast of these and other POEMs that appear in AFP,search in iTunes for “POEM of the Week” or go to http://goo.gl/3niWXb.

This series is coordinated by Sumi Sexton, MD, Associate Medical Editor.

A collection of POEMs published in AFP is available at https://www.aafp.org/afp/poems.



Want to use this article elsewhere? Get Permissions

More in AFP

Editor's Collections

Related Content

More in Pubmed


Oct 2021

Access the latest issue of American Family Physician

Read the Issue

Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now

Navigate this Article