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

Related ObG Topics:

Progesterone or Cerclage in Preterm Prevention in Women with Previous Preterm Birth and Short Cervix?

Does Vaginal Progesterone Improve Birth Outcomes for Mothers with Short Cervix?

Does Cervical Pessary Benefit Women at risk for Preterm Birth due to Short Cervix?