title: Cervical pessary placement for prevention of preterm birth in unselected twin pregnancies: a randomized controlled trial.
abstract: BACKGROUND
  Preterm birth is the leading cause of neonatal death and handicap in survivors. Although twins are found in 1.5% of pregnancies they account for about 25% of preterm births. Randomized controlled trials in singleton pregnancies reported that the prophylactic use of progestogens, cervical cerclage and cervical pessary reduce significantly the rate of early preterm birth. In twin pregnancies, progestogens and cervical cerclage have been shown to be ineffective in reducing preterm birth.
  
  
  OBJECTIVE
  The objective of this study was to test the hypothesis that the insertion of a cervical pessary in twin pregnancies would reduce the rate of spontaneous early preterm birth.
  
  
  METHODS
  This was a multicenter, randomized controlled trial in unselected twin pregnancies of cervical pessary placement from 20(+0)-24(+6) weeks' gestation until elective removal or delivery vs. expectant management. Primary outcome was spontaneous birth <34 weeks. Secondary outcomes included perinatal death and a composite of adverse neonatal outcomes (intraventricular haemorrhage, respiratory distress syndrome, retinopathy of prematurity or necrotizing enterocolitis) or need for neonatal therapy (ventilation, phototherapy, treatment for proven or suspected sepsis, or blood transfusion). Analysis was by intention to treat. This trial is registered in the ISRCTN registry, number 01096902.
  
  
  RESULTS
  A total of 1,180 (56.0%) of the 2,107 eligible women agreed to take part in the trial; 590 received cervical pessary and 590 had expectant management. Two of the former and one of the latter were lost to follow up. There were no significant differences between the pessary and control groups in rates of spontaneous birth <34 weeks (13.6% vs. 12.9%; relative risk 1.054, 95% confidence interval [CI] 0.787-1.413; p=0.722), perinatal death (2.5% vs. 2.7%; relative risk 0.908, 95% CI 0.553-1.491; p=0.702), adverse neonatal outcome (10.0 vs. 9.2%; relative risk 1.094, 95% CI 0.851-1.407; p=0.524) or neonatal therapy (17.9% vs. 17.2%; relative risk 1.040, 95% CI 0.871-1.242; p=0.701). A post hoc subgroup analysis of 214 women with short cervix (≤25 mm) showed no benefit from the insertion of a cervical pessary.
  
  
  CONCLUSIONS
  In women with twin pregnancy, routine treatment with cervical pessary does not reduce the rate of spontaneous early preterm birth.
authors: Harris Birthright Research Center for Fetal Medicine, King's College, London, United Kingdom. Electronic address: kypros@fetalmedicine.com.
authors: Kypros H
authors: KH
authors: Nicolaides
authors: Harris Birthright Research Center for Fetal Medicine, King's College, London, United Kingdom.
authors: Argyro
authors: A
authors: Syngelaki
authors: Harris Birthright Research Center for Fetal Medicine, King's College, London, United Kingdom.
authors: Liona C
authors: LC
authors: Poon
authors: Department of Obstetrics and Gynecology, Hospital Universitario Virgen de La Arrixaca, Murcia, Spain.
authors: Catalina
authors: C
authors: de Paco Matallana
authors: Maternal Fetal Medicine Unit, Hospital Universitario Materno Infantil de Canarias, Las Palmas de Gran Canaria, Canary Islands, Spain.
authors: Walter
authors: W
authors: Plasencia
authors: Department of Obstetrics and Gynecology, University Hospital of Granada, Granada, Spain.
authors: Francisca S
authors: FS
authors: Molina
authors: Department of Fetal Medicine, Medway Maritime Hospital, Gillingham, United Kingdom.
authors: Gemma
authors: G
authors: Picciarelli
authors: Department of Perinatology, Division of Obstetrics and Gynecology, University Medical Center Ljubljana, Slovenia.
authors: Natasa
authors: N
authors: Tul
authors: Harris Birthright Research Center for Fetal Medicine, King's College, London, United Kingdom.
authors: Ebru
authors: E
authors: Celik
authors: Department of Obstetrics and Gynecology, Chinese University of Hong Kong, Hong Kong, China.
authors: Tze Kin
authors: TK
authors: Lau
authors: Department of Obstetrics and Gynecology, Ospedale Valduce, Como, Italy.
authors: Roberto
authors: R
authors: Conturso
mesh_terms: D000328:Adult; D002584:Cervix Uteri / Q000000981:diagnostic imaging; D020345:Enterocolitis, Necrotizing / Q000517:prevention & control; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D057194:Intention to Treat Analysis; D020300:Intracranial Hemorrhages / Q000517:prevention & control; D066087:Perinatal Death / Q000517:prevention & control; D010570:Pessaries; D011247:Pregnancy; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000517:prevention & control*; D012127:Respiratory Distress Syndrome, Newborn / Q000517:prevention & control; D012178:Retinopathy of Prematurity / Q000517:prevention & control; D014463:Ultrasonography; D057832:Watchful Waiting
keywords: Arabin pessary; cervical length; neonatal morbidity; prematurity; preterm birth; sonographic short cervix; twins