Cervical preparation for second-trimester surgical abortion prior to 20 weeks of gestation

Roughly 11% of induced abortions in the United States are performed after 14 weeks of gestation, most commonly by dilation and evacuatio (D&E). For aD&Eprocedure, the cervixmust be dilated sufficiently to allow passage of operative instruments and products of conceptionwithou injuring the uterus or cervical canal. Preoperative preparation of the cervix reduces the risk of cervical laceration and uterine perforation. Th cervix may be prepared with osmotic dilators, prostaglandin analogues, or both. Osmotic dilators currently available in the United States includ Dilapan-STM, Lamicel, and laminaria. Laminaria tents are made from dehydrated seaweed and require 12–24 h to achieve greatest dilation. Th synthetic products, Dilapan-STM and Lamicel, achieve maximum effect within 6 h. Dilapan-STM achieves greater dilation than the others and thus, requires fewer dilators to be placed but may bemore difficult to remove. For same day procedures, Dilapan-STM and Lamicel are preferabl to laminaria. A single set of one to several dilators is usually adequate for D&Ebefore 20weeks of gestation.Additional sets over 1–2 daysmay b needed in challenging cases. Misoprostol, a prostaglandin analogue, is sometimes used instead of osmotic dilators; however, the data to suppo such use are limited. Misoprostol is inferior to overnight dilation with laminaria for cervical priming prior to D&E. Misoprostol use as an adjunc to overnight osmotic dilation is only marginally beneficial for priming beyond 16 weeks and does not truly demonstrate any benefit befor 19 weeks of gestation. Limited data demonstrate the safety of misoprostol prior to D&E in patients with a uterine scar. The Society of Famil Planning recommends preoperative cervical preparation to decrease the risk of complications when performing a D&E prior to 20 weeks o gestation. The three currently available osmotic dilators (laminaria, Lamicel, andDilapan-STM) are safe and effective for this use. Since no singl protocol has been found to be superior, clinical judgment is warranted when selecting a method of preoperative cervical preparation. © 2007 Elsevier Inc. All rights reserved.