BACKGROUND AND PURPOSE:

• Broad classification of preterm birth
  • Iatrogenic preterm birth
  • Spontaneous preterm birth (sPTB)
    • Spontaneous preterm labor (PTL) with intact membranes (IM)
    • Preterm prelabor rupture of membranes (PPROM)
• Care et al. (Ultrasound in Obstetrics and Gynecology, 2018) investigated whether the above classification of a previous sPTB alters the efficacy of pessary or vaginal progesterone in subsequent pregnancies with short cervix

METHODS:

• Retrospective cohort study
  • Multicenter (2008-2015)
• Participants
  • Pregnancy with short cervix and a history of sPTB
  • Otherwise asymptomatic | Singleton
  • No congenital anomalies
• Classification
  • PTL-IM: ≤34 weeks
  • PPROM: ≤34 weeks
• Definition of ‘short cervix’
  • Single measurement of ≤ 25 mm or
  • < 3rd centile for gestational age
• Treatments for primary PTB prevention
  • Arabin pessary or
  • Vaginal progesterone: 200 mg at night
• Primary outcome: Gestational age at delivery with exclusion of the following
  • Additional cerclage
  • Swapped therapies
  • Additional treatments
• Secondary outcomes: All women included
• Analysis
  • Linear regression analysis used based on (1) treatment type (2) cervical length (3) previous sPTB classification

RESULTS:

• 170 women were treated with pessary | 88 were treated with vaginal progesterone
• Women with history of PPROM delivered earlier (35 weeks) than PTL-IM (38 weeks); P ≤ 0.001
• Treated with pessary: sPTB <34 weeks rate was
  • PTL-IM: 16%
  • PPROM: 55%
• Treated with vaginal progesterone: sPTB <34 weeks was
  • PTL-IM: 15%
  • PPROM: 21%
  • No difference in duration of pregnancy in this group regardless of PTL-IM or PPROM
• Overall, Pessary treatment for women with previous PPROM resulted in greatest percentage of sPTB <34 weeks (P < 0.0001)
• Independent factors affecting early gestational age at birth
  • PPROM history (P < 0.0001)
  • Combination of PPROM history and treatment type (P= 0.0003)
  • Cervical length (P=0.0004)

CONCLUSION:

• Cervical pessary appears to be least efficacious therapy for women with short cervix, history of sPTB and PPROM
• Authors conclude that
  • Classification system of prior sPTB may be helpful in determining management in subsequent pregnancies
  • Previous history may account for conflicting results regarding benefit of pessary for prevention of sPTB in the setting of short cervix
  • Prospective studies would be necessary prior to change in clinical practice

Learn More – Primary Sources:

Should phenotype of previous preterm birth influence management of women with short cervix in subsequent pregnancy? Comparison of vaginal progesterone and Arabin pessary

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