Cervical dilation before first-trimester surgical abortion (<14 weeks' gestation)

Abstract

First-trimester surgical abortion is a common, safe procedure with a major complication rate of less than 1%. Cervical dilation before suction aspiration is usually accomplished using tapered mechanical dilators. Risk factors for major complications in the first trimester are increasing gestational age and provider inexperience. Use of laminaria for cervical priming reduces the risk of cervical laceration and, to a lesser extent, uterine perforation. While pharmacological priming agents may potentially have the same effects, no published studies to date have been large enough to assess these outcomes. Given an experienced provider, the risk of these injuries during suction aspiration is very small.

Cervical priming can be achieved with osmotic dilators or pharmacological agents. The advantages of osmotic dilators such as laminaria, Dilapan-S™ and Lamicel® are their ability to produce wide cervical dilation, and for the synthetic types, their advantages include predictable effects and rapid onset of action. A disadvantage of osmotic dilators is that they require a speculum examination and a trained clinician to perform the insertion. When cervical priming is performed, misoprostol is the prostaglandin analogue most commonly used worldwide. Compared to laminaria, vaginal misoprostol requires a shorter period of time to achieve the same dilatation, is associated with less discomfort and is preferred by women. The sublingual route appears as effective as vaginal administration and requires less time for priming (2 h), but it is associated with more side effects. Oral administration can produce equivalent dilation to vaginal or sublingual administration, but higher doses and longer treatment periods (8 to 12 h) are required. Buccal administration of misoprostol appears to have a pharmacokinetic and physiologic profile similar to vaginal administration; however, there are no published studies of buccal misoprostol prior to first-trimester suction abortion.

While extensive data demonstrate that a variety of agents are safe and effective at causing cervical softening and dilation preoperatively, there are not enough data to conclude that routine cervical priming is necessary to reduce complications of first-trimester surgical abortion. Cervical priming increases preoperative cervical dilation, making the procedure easier and quicker for the physician. However, in order to preoperatively dilate the cervix, the woman must receive the agent at least 3 to 4 h prior to her procedure. Besides the additional waiting, the woman might experience bleeding and cramping prior to the procedure. There are insufficient data evaluating how cervical priming affects women's quality of life in relation to abortion. Based on existing evidence, the Society of Family Planning does not recommend routine cervical priming for suction aspiration procedures. The Society of Family Planning further recommends that providers consider cervical priming only for women who may be at increased risk of complications from cervical dilation, including those late in the first trimester, adolescents and women in whom cervical dilation is expected to be difficult due to either patient factors or provider experience.