RT Book, Section A1 Li, Yunping A1 Shainker, Scott A. A2 Hess, Philip E. A2 Li, Yunping A2 Kowalczyk, John J. A2 Stiles, Justin K. SR Print(0) ID 1199673769 T1 Cerclage T2 Obstetric Anesthesia: Quick References & Practical Guides YR 2023 FD 2023 PB McGraw Hill PP New York, NY SN 9781264671465 LK obgyn.mhmedical.com/content.aspx?aid=1199673769 RD 2024/03/29 AB Cervical insufficiency affects about 1% of all pregnancy. It is defined as painless cervical dilation in the second trimester. Cervical insufficiency can be preceded by cervical shortening (less than 2.5 cm). It is associated with an increased risk of preterm labor and birth.