Progesterone for maintenance tocolytic therapy after threatened preterm labour: a randomised controlled trial

Women with preterm labour that is arrested with tocolytic therapy are at increased risk of recurrent preterm labour. The efficacy of maintenance tocolytic therapy after successful arrest of preterm labour remains controversial.

The purpose of this study was to determine whether supplementation of vaginal progesterone after inhibition of preterm labour is associated with an increased latency period and a decreased recurrent of preterm labour.

This trial was conducted in 70 women who presented with symptoms of threatened preterm labour, who after arrest of uterine activity were then randomised to progesterone therapy or no treatment. Treatment group received progesterone suppository (400 mg) daily until delivery and control group received no treatment.

Longer mean latency until delivery (36/11 +/- 17/9 vs 24/52 +/- 27/2) (mean + standard deviation) days; respiratory distress syndrome 4 (10.8%) vs 12 (36.4%) P = 0.021; low birthweight 10 (27%) vs 17 (51.5%) P = 0.04; and birthweight (3101.54 +/- 587.9 g vs r 2609.39 +/- 662.9 g, P = 0.002), were significantly different between the two groups. No significant differences were found between recurrent preterm labour 13 (35.1%) vs 19 (57.6%), P = 0.092; admission to intensive care unit 9 (24.3%) vs 13 (39.4%), P= 0.205 ; and neonatal sepsis 2 (5.4%) vs 6 (18.2%) P = 0.136, for the progesterone and control groups, respectively.

The use of vaginal progesterone suppository after successful parenteral tocolysis associated with a longer latency preceding delivery but failed to reduce the incidence of readmission for preterm labour.