Prophylactic PV progesterone - high risk sPTB

Question 1

What was the hypothesis of this study?

Answer 1

Prophylactic PV progesterone reduces the incidence of PTB in high risk population by 50% (i.e. from 25% down to 12.5%)

Question 2

What type of study was this?

Answer 2

Randomised, double-blinded, placebo-controlled study.

Question 3

What was the inclusion criteria?

Answer 3

Inclusion:

• singleton
• high risk of PTB (previous spontaneous PTB, prophylactic cervical cerclage, uterine malformation)

Question 4

What was the exclusion criteria?

Answer 4

Exclusion:

• multiple gestation
• fetal malformations
• allergy to progesterone
• preterm ROM
• iatrogenic PTB

Question 5

Describe the study groups and method:

Answer 5

Treatment group: PV progesterone.
Control group: PV placebo.
Method:
- GA calculated by LMP, early dating scan or two concordant scans 12-20 weeks.
- Vaginal swabs and treatment of any genital tract infections including BV; then test of cure.
- Weekly external tocodynamometer for 60 mins from 24-34 weeks; 8-10 am.

Question 6

What were the primary outcomes?

Answer 6

Primary outcomes:

• PTB <37 weeks
• Very PTB <34 weeks
• Uterine activity

Question 7

What were the secondary outcomes?

Answer 7

Secondary outcomes:

• B-agonists delaying PTB by more than 72 hours.
• Interval time to second episode of PTL

Question 8

What were the main findings and conclusions from this study?

Answer 8

In the PV progesterone group:

• Less uterine activity
• Lower rate of PTB
• Lower rate of very PTB
• B-agonist tocolysis was more effective
• Longer interval time between episodes of PTL

Conclusions: PV progesterone reduces rate of PTB in high risk population.

Question 9

What were the weaknesses of this study?

Answer 9

Weaknesses:

• Did not explicitly outline primary and secondary outcomes.
• Small study population (142)
• Was not multicentre.
• Unclear mechanism of action of progesterone.