RT Journal Article SR Electronic T1 Review: excisional, and perhaps ablative treatments for precancerous cervical changes increase the risk for preterm birth JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 92 OP 93 DO 10.1136/ebm.2011.100238 VO 17 IS 3 A1 Crane, Joan YR 2012 UL http://ebm.bmj.com/content/17/3/92.abstract AB