Table 1: Prospective cohort studies.

AuthorYearCountryNo. of womenInclusion criteriaExclusion criteriaAgeType of pessaryPregnancy outcomeNeonatal outcomePessary removal and side effects

Quaas1990Germany107 Women with history of miscarriages
Preterm birth, multiple pregnancies,
Cervical conization, cervical tear, cervical
Ripening (bishop score >6), dilation or
Prolapsed membranes
Not clearly statedNot statedArabin 92% of women treated with pessary delivered >36 weeksNot stated36 weeks of gestation

Arabin2003The Netherlands11History of spontaneous preterm birth <36 weeks and a CL <15 mm (singletons and twins)Severe regular contractions
Blood loss
Premature rupture of membranes
24–43 yearsArabin Singletons:
mean GA at delivery 35 + 3 weeks
Twins:
mean GA at delivery 35 weeks
Pessary versus control:
singletons <28 weeks: 0 (0%) versus 2 (17%)
<32 weeks: 0 (0%) versus 3 (25%)
<36 weeks: 0 (0%) versus 6 (50%)
Pessary versus control: twins
<28 weeks: 0 (0%) versus 1 (4%)
<32 weeks: 0 (0%) versus 7 (30%)
<36 weeks: 8 (35%) versus 12 (52%)
Not stated17 (58%) complains of discharge
13 (44%) pain during insertion
15 (52%) pain during removal
28 (97%) recommend to others

Antczak-Judycka2003Poland57Women with a risk of PTB:
shortening of cervical length or dilatation between 22–27 weeks
Intrauterine infection
contractions
Urine tract infection
Vaginal infection
20–46Not defined Cerclage versus pessary
Prolongation of pregnancy:
13.4 (±3 weeks) versus 12.1 (±3 weeks)
Mean GA at delivery:
37.3 (±2 weeks) versus 37.7 (±3 weeks)
Delivery >37 weeks:
17 (77%) versus 31 (89%)
Cerclage versus pessary
birthweight:
3080 ± 676 versus 3063 ± 826
Apgar score 5 min: “good”
perinatal death:
2 (6%) pessary group
Cerclage versus pessary
PPROM: 1 (5%) versus 2 (6%)
Premature contractions: 2 (10%) versus 2 (6%)
Cervical tear: 3 (15%) cerclage group
Pessary dislocation: 1 (3%)

Acharya2006Norway32 (21 singletons, 9 twins, 2 triplet)Women with a riskfactor for PTB and a short CL (<25 mm) before 30 weeks of GANo viable fetus or congenital malformations23–39 yearsArabin Delivery <28 weeks: 6 (20.7%)
Delivery <34 weeks: 13 (45%)
Mean GA at delivery 34 weeks
Mean birthweight: 2255 g
Mean Apgar score at 5 min: 8
Perinatal death: 4 (14%)
34 + 36 weeks
2 removal due to pain
Increased discharge in all women

Sieroszewski2009Poland54Singleton pregnancies with a CL 15–30 mm before 28 weeks Multiple pregnancies
Fetal malformations
Uterine contractions
PPROM
Blood loss
Abnormal placenta localisation
<20 years 1 (1.9%)
20–34 years 47 (87%)
35–39 years 4 (7.4%)
>37 years 2 (3.7%)
Arabin Delivery <37 weeks: 9 (16.7%)
Mean GA at delivery 35.3 weeks
Apgar score scales:
0–4: 2 children (3.7%)
5–7: 7 (13%)
8–10: 45 (83.3%)
NICU admission: 2 (39%)
0 neonatal deaths
Mean gestational age at removal 33.3 weeks
No complications or side effects

Kimber-Trojnar2010Poland 56Women with a riskfactor for PTB: history miscarriages, prior PTB <34 weeks, cervical suture in previous pregnancy, history of cervicalContractions, ruptured membranes, maternal pyrexia, elevated CRP or white blood cell count, vaginal 19–43 yearsPolyvinyl chloride pessaryDelivery <34 weeks: 2 (3.6%)
Delivery 34–37 weeks: 6 (10.7%)
Delivery >37 weeks: 48 (85.7%)
Mean birthweigth: 3255
Mean Apgar score at 3 min: 9, 6
58 (100%) live born infants
7 (12.5%) NICU admission
37 weeks, contractions vaginal bleeding, discomfort fetal distress, ruptured membranes