Prevention of Preterm Delivery in Twin Pregnancies by 17 Alpha-hydroxyprogesterone Caproate
Status:
Completed
Trial end date:
2012-12-01
Target enrollment:
Participant gender:
Summary
Preterm birth remains a major cause of perinatal morbidity and mortality in developing as
well as in developed countries. Despite major clinical research efforts aimed at reducing the
incidence of preterm births in the United States, the preterm birth rate reached its highest
level in 2 decades, 11.9% in 2001, which translates to a 27% rise since 1981. Much of this
increase may be accounted for by the increase in multiple gestations brought about by
assisted reproductive technology. Twin gestations accounting for 20% to 25% of all
pregnancies conceived following such procedures. Twin gestations are at a particularly
increased risk of preterm labor and they deliver at a mean gestational age of 37 weeks
compared to 40 weeks for singleton pregnancies. In a study by our group, we estimated that
about 54.5% of twin gestations would deliver prior to 37 completed weeks of gestation; i.e.
preterm.
Evidence regarding efficacy of interventions designed to prevent preterm birth has been
disappointing. Most well-designed clinical trials have failed to demonstrate any reduction in
preterm births with such interventions as home uterine activity monitoring, reduced physical
activity, administration of antibiotic or tocolytic therapy, and intensive and frequent
antenatal follow ups. Recently, progesterone has shown some promise in the prevention of
preterm birth among women with prior preterm births. Whether this intervention will prove
effective in other populations, such as women with multiple gestations, remains to be seen.
The objective of our study is to compare the effectiveness of weekly intramuscular injections
of 17-alpha Hydroxyprogesterone Caproate, a natural metabolite of progesterone, in preventing
delivery at less than 37 weeks of gestation in a population of 290 patients with twin
gestations between 16 and 36 weeks of gestation compared to a placebo. The data generated
will be invaluable in managing this group of patients that is considered at a very high risk
for preterm labor and delivery.