From the Editor

Advances in the treatment of fetal demise in the second and third trimester

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Treatment of fetal demise is best managed as a 2-step process, beginning with cervical preparation using cervical dilators, cervical balloons, mifepristone and/or misoprostol, and followed by emptying the uterus using surgical evacuation or induction of labor with misoprostol or oxytocin


 

References

Clinical care for fetal demise is complex and multidimensional, including empathic emotional support for the patient and family members who are experiencing a tragedy, investigation of the cause of the demise, and a plan for emptying the uterus. This editorial narrowly focuses on the options for treatment of fetal demise with the goal of emptying the uterus while minimizing complications.

When planning treatment of fetal demise, focus on fetal size and gestational age

Most guidelines for the treatment of fetal demise use gestational age to guide selection of a treatment.1,2 I believe that fetal size is as important as gestational age for selecting a treatment plan. When considering treatment, there are 2 reasons why fetal size is as important as gestational age:

  • The physiologic processes that caused fetal demise may have caused fetal growth restriction, resulting in a fetal size that is 2 or more weeks below expected fetal size for gestational age.
  • Fetal demise may have occurred weeks before the diagnosis was made, resulting in gestational age being greater than fetal size. This editorial will use ultrasonography estimate of fetal size in gestational weeks to guide treatment recommendations. When discussing fetal size, we will use the convention of weeks-days (w-d). Twenty-five weeks and zero days gestation is represented as 25w0d.

Treatment in the second and third trimester is a 2-step process

Step 1: Cervical preparation

In most cases of first trimester fetal demise, no cervical preparation is necessary. Cervical dilation with metal dilators followed by uterine evacuation with an appropriately sized vacuum catheter is a highly successful treatment.3 However for second and third trimester fetal demise, it is best to use a 2-step process, beginning with cervical preparation followed by emptying the uterus. For example, at a fetal size of 13w0d to 16w0d, cervical preparation can be achieved by administering a single buccal dose of misoprostol 400 µg 3 to 4 hours prior to uterine evacuation or by inserting a Dilapan-S (Medicem Inc) osmotic cervical dilator 3 to 6 hours prior to uterine evacuation.4-7 At a fetal size of 16w0d to 19w6d, cervical preparation can be achieved by placing osmotic cervical dilators 4 to 6 hours before surgical evacuation and administering buccal misoprostol 400 µg 3 hours before surgical evacuation.8

Alternatively, from 16w0d to 25w0d osmotic cervical dilators can be placed on day 1 of a 2-day process, and the patient can return on day 2 to have the cervical dilators removed followed by surgical evacuation of the uterus. Mifepristone 200 mg oral dose can be administered on day 1 to facilitate cervical preparation. In my practice, I use mifepristone 200 mg on day 1 when the fetal size is ≥20w0d gestation. Options for cervical preparation include use of osmotic dilators, cervical balloons, misoprostol, and/or mifepristone. These options are discussed below. With fetal demise, natural physiologic processes often have caused sufficient cervical softening and dilation that no cervical preparation is necessary and immediate uterine surgical evacuation or induction of labor can be initiated.

Step 2: Emptying the uterus

In the second and third trimesters, the approach to uterine evacuation is based on fetal size. At fetal sizes <25w0d, options for emptying the uterus include surgical evacuation with a vacuum catheter and grasping forceps or induction of labor with misoprostol followed by vaginal birth and expulsion of the placenta. At fetal sizes ˃25w0d gestation, following completion of cervical preparation, the most common approaches to uterine evacuation are induction of labor with misoprostol or oxytocin. Rarely, with a stillbirth at term, some clinicians will select hysterotomy to empty the uterus, avoiding uterine rupture during labor induction for patients at the highest risk, including those with a prior classical cesarean birth or more than 2 prior cesarean births with a low-transverse uterine incision.

Osmotic cervical dilators

The 2 most used cervical dilators are Dilapan-S, a polyacrylate-based hydrogel rod, and laminaria, dried compressed seaweed stipe (stalk) from Laminaria japonica or Laminaria digitata. Dilapan-S rods are available in diameters of 3 mm and 4 mm and rod lengths of 55 mm and 65 mm. Laminaria dilators are available in diameters of 2, 3, 4, 5, 6, 8 and 10 mm and rod length of 60 and 70 mm. Dilapan-S dilators reach near-maximal dilation in approximately 4 to 6 hours but continue to expand over the following 18 hours to achieve a maximum dilation of 3.3 to 3.6 times their dry diameter.9 Laminaria dilators expand to 2.7 to 2.9 times their dry diameter over 24 hours.9

A general rule is that as many dilators as possible should be placed until significant resistance to the placement of additional dilators is encountered.10 In my practice, for fetal size ≥20 weeks’ gestation, I place 2 Dilapan-S rods, 4 mm in diameter, 55 mm in length, and then encircle the Dilapan-S with laminaria rods that are 4 mm in diameter and 60 mm in length. Once cervical resistance to the placement of the 4 mm laminaria rods is observed, I encircle those laminaria with laminaria 2 mm in diameter, filling in the interstices between the 4 mm laminaria. The next day, cervical dilation is routinely ≥3 cm.

In a retrospective study of 491 patients undergoing pregnancy termination after 14 weeks’ gestation, with a mean gestational age of 24 weeks, compared with no osmotic cervical dilators, inserting osmotic cervical dilators the day before initiating misoprostol for induction of labor resulted in a decrease in time to delivery (428 min vs 640 min; P<.001) and a decrease in total misoprostol dose (990 µg vs 1,449 µg; P<.0001).11

Cervical balloons

All clinicians know that a Foley catheter or a Cook cervical ripening balloon can be used for cervical preparation in the third trimester.12,13 The Foley catheter also has been reported to be useful for cervical preparation in the second trimester. In one study of 43 patients 17 to 24 weeks’ gestation scheduled for a second-trimester dilation and evacuation, an intracervical Foley catheter was placed the evening before evacuation, and the balloon was inflated with 30 mL to 50 mL of saline. At the same time, mifepristone 200 mg was administered to the patients.14 The following day, dilation and evacuation was performed. In 72% of cases no additional cervical dilation was required on the day of evacuation. The investigators concluded that if osmotic cervical dilators are not available, the placement of an intracervical Foley catheter plus administration of mifepristone facilitates performance of an evacuation on the following day. If the patient prefers a 1-day procedure, the Foley can be inserted in the morning to facilitate cervical preparation, and the uterus can be evacuated in the afternoon.

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