Prophylactic Administration of Natural Progesterone in the Prevention of Preterm Delivery in Twin Pregnancies
Condition: Preterm Delivery
MeSH terms: Premature Birth
Study type: Interventional
Phase: Phase 4

Summary: 
      Twin pregnancies are at substantial increased risk of preterm delivery. Prophylactic
      administration of progesterone in singleton pregnancies at risk of preterm delivery has been
      shown to be effective in reducing the rate of such complication. The aim of this study is to
      investigate the effect of prophylactic administration of natural progesterone in twin
      pregnancies on the rate of preterm births.
    

Detailed description: 
      In a double-blind, placebo controlled study performed in our Institution, Fonseca et al.,
      investigated the use of micronized natural progesterone, crafted in vaginal capsules of
      100mg, for the prevention of preterm delivery. The study involved 142 singleton pregnancies
      at high risk for premature birth (previous premature birth, cerclage and uterine
      malformation). The progesterone was introduced from 24 weeks to 34 weeks gestation. The
      authors observed a significant reduction of premature birth before 37 weeks (28,1% within the
      placebo group versus 13,8% within the treated group) and below 34 weeks (18,6% within the
      placebo group versus 2,8% within the treated group). Also, it was observed a reduction in the
      frequency of the uterine contractions in the progesterone group.

      In the only study performed specifically among twin pregnancies, Anna Lisa et al. in 1980,
      administrated 250mg of 17αOH-PC or placebo (still oil) weekly, in 70 pregnant women with twin
      pregnancies, beginning before 28 weeks and continuing up to 37 weeks gestation. Seric levels
      of progesterone, estradiol, estriol, testosterone, and placental lactogenic hormone were also
      measured weekly. The differences among the achieved results within both groups, according the
      average in pregnancy duration (36,9 within the treated group, versus 37,3 within the placebo
      group), the average birthweight and the perimortality rate were not significantly different,
      as well as the levels of progesterone, estriol, estradiol, testosterone and placental
      lactogenic hormone. Nevertheless, this study was criticized for starting the use of
      progesterone at a late stage of pregnancy, in a considerable number of cases.

      These studies suggest that in singleton pregnancies with a previous history of preterm birth
      progesterone treatment may prevent the patients from having subsequent premature births.
      Nonetheless, the results of these series must not be generalized to all pregnancies at high
      risk. Additional studies to evaluate the use of progesterone ovules in multiple pregnancies
      are necessary, as these pregnancies are increasing due to the advanced maternal age at the
      conception time and also due to the widespread use of assisted reproductive techniques.
    

Intervention name(s): progesterone; placebo
Intervention type(s): Drug; Drug
Intervention description(s): ovules, 200mg per vagina, once a day from 18 weeks; placebo
Other intervention name(s): utrogestan
Intervention MeSH terms: Progesterone
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: twin pregnancies; preterm delivery; progesterone