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Cervical cerclage for the woman with prior adverse pregnancy outcome

Diagnosis/definition: The American College of Obstetricians and Gynecologists (AGOG) defines cervical insufficiency as "the inability of the uterine cervix to retain a pregnancy to term." The presence of both: one or more prior early PTBs and/or second-trimester losses, and TVU CL less than 25 mm or cervical dilatation (eg, >1 cm) on digital examination before 24 weeks in the current pregnancy may arouse suspicion of cervical insufficiency.
Risk factors/associations: [Prior preterm birth], repeated cervical dilation for pregnancy terminations or losses, cervical procedures such as cold-knife or laser cervical conization and loop electrosurgical excision procedures, cervical lacerations or urogenital abnormalities, etc.
o    Screening/Work-up: Patients presenting with suspected cervical insufficiency should be assessed for the presence of any other risk
factors for early PTB, and the medical records of the prior pregnancy should be reviewed for details such as fetal karyotype, fetal anomalies, infection, and any available workup.
o    Prenatal care:

  • A "history-indicated" cerclage is placed about 12 to 14 weeks after confirmation of a viable intrauterine pregnancy for the sole criterion of prior adverse pregnancy outcome. The only adverse pregnancy history that has been, associated with benefit from history-indicated cerclage is a history of 3 or more PTBs or second-trimester losses.
  • Available data from randomized, controlled trials of women with 1 or more prior early PTBs suggest that TVU screening with cerclage placement if CL shortens is associated with similar perinatal outcomes (including PTB) as routine history-indicated cerclage. In general, only about 40% of women with prior PTBs,
  • Develop early cervical shortening. Therefore, TVU CL can result
  • in avoidance of cerclage in the majority of women with suspicious histories such as prior late second-trimester or early third-trimester PTBs.
  • When the diagnosis [of cervical insufficiency] is unclear, evaluation of early cervical changes can be considered, with TVU CL starting usually around 16 weeks. Screening earlier than 16 weeks {eg, 14 weeks) may be considered only if a patient has a history of very early second-trimester losses.14 A 2-week interval for TVU CL was used in most trials and is thus useful in clinical practice. If the initial or subsequent CL is 25 mm to 29 mm, then a weekly interval should be considered. Such TVU CL screening identifies about 70% of high-risk women who will deliver preterm.
  • If the CL shortens to less than 25 mm before 23 0/7 weeks in a woman with prior spontaneous PTB at 17 to 33 6/7 weeks, placement of cerclage may be offered to the patient.
  • Either a McDonald or Shirodkar cerclage may be used. The McDonald technique is preferred by most surgeons because of its ease in placement and removal, as well as its study-proven effectiveness.
  • The use of 17-alpha hydroxyprogesterone caproate (17P) has been associated with a more than 30% decrease in recurrence of PTB in women with prior spontaneous PTB between 20 and 36 weeks. Given as an intramuscular injection of 250 mg, 17P should be initiated at 16 weeks and continued weekly until 36 weeks.

Last Reaffirmed: Feb 1, 2015