Preterm labour and birth

Prophylactic cervical cerclage compared with prophylactic vaginal progesterone for preventing preterm birth:- What is the clinical effectiveness of prophylactic cervical cerclage alone compared with prophylactic vaginal progesterone alone and with both strategies together for preventing preterm birth in women with a short cervix and a history of spontaneous preterm birth?

Identifying infection in women with preterm prelabour rupture of membranes (P-PROM):- What is the diagnostic accuracy of serial C-reactive protein testing to identify chorioamnionitis in women with P-PROM?

Effectiveness of 'rescue' cerclage:- What is the clinical effectiveness of 'rescue' cerclage in improving outcomes for women at risk of preterm birth?

Magnesium sulfate for neuroprotection: bolus plus infusion compared with bolus alone:- What is the clinical effectiveness of a bolus plus infusion of magnesium sulfate compared with a bolus alone for preventing neurodevelopmental injury in babies born preterm?

Does progesterone reduce the risk of preterm birth in women who have risk factors for preterm birth, but do not have a short cervix (cervical length of more than 25 mm)?

Does progesterone reduce the risk of preterm birth in women who have a short cervix (cervical length of 25 mm or less), but do not have other risk factors for preterm birth? 

At what gestation should treatment with prophylactic vaginal progesterone for the prevention of preterm birth be started and stopped?