Prophylactic cerclage for the prevention of preterm delivery

Systematic review: Cervical stitch (cerclage) for preventing pregnancy loss: individual patient data meta‐analysis

“…No woman was entered more than once into the trials of To et al, 13 Berghella et al 9 and Althuisius et al, 8 and we have not obtained confirmation either way regarding the trial of Ezechi et al 10 Since it was not always clear which women were entered more than once, we have assumed that all pregnancies are independent regardless of the fact that in some instances the same woman contributed with more than one pregnancy.…”

“…It was, therefore, not possible to replicate published results for some of the variables. Data on Althuisius et al 8 Berghella et al 9 Ezechi et al 10 MRC 4 Rush et al 11 Rust et al 12 To et al 13 Cerclage …”

“…14 It was not possible to analyse the outcome 'pregnancy loss or neonatal death at any time' since most trials 4,8,9,11,13 followed up to hospital discharge only. For trials where length of follow up was unclear, 10 we assumed that follow up was to hospital discharge only. Furthermore, it was confirmed that although follow up continued after hospital discharge, all deaths in the trial of Rust et al 12 occurred before discharge.…”

“…Table 1. Standardising outcome measures across trials Althuisius et al 8 Berghella et al 9 Ezechi et al 10 MRC 4 Rush et al 11 Rust et al 12 To et al 13 Neonatal mortality Althuisius et al 8 Berghella et al 9 Ezechi et al 10 MRC 4 Rush et al 11 Rust et al 12 To et al 13 Pyrexia of any detectable neonatal morbidity at discharge. Table 1 summarises the data recorded on this outcome in each trial, and how these were classified for the purposes of this analysis.…”

“…Although the cerclage intervention varied with seven trials using a McDonald type suture, [8][9][10][11][12]18,19 one trial using a Shirodkar type 13 and one trial using a combination of more than one type of suture 4 undertaking a meta-analysis was deemed appropriate. For two of the eligible trials, the authors subsequently confirmed that IPD were no longer available, and hence these trials have been excluded from our IPD analyses (Lazar et al, 19 Dor et al 18 ).…”