Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: a randomized placebo-controlled double-blind study
da Fonseca EB,Bittar RE,Carvalho MH,Zugaib M
Published February 20, 2003American Journal of Obstetrics and Gynecology, 188(2), 419-424
da Fonseca, E. B., Bittar, R. E., Carvalho, M. H., & Zugaib, M. (2003). Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: a randomized placebo-controlled double-blind study. American Journal of Obstetrics and Gynecology, 188(2), 419-424. https://doi.org/10.1067/mob.2003.41
da Fonseca EB, Bittar RE, Carvalho MH, Zugaib M. Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: a randomized placebo-controlled double-blind study. Am J Obstet Gynecol. 2003;188(2):419-424. doi:10.1067/mob.2003.41
da Fonseca, Eduardo B., et al. "Prophylactic administration of progesterone by vaginal suppository to reduce the incidence of spontaneous preterm birth in women at increased risk: a randomized placebo-controlled double-blind study." American Journal of Obstetrics and Gynecology, vol. 188, no. 2, 2003, pp. 419-424.
Vaginal progesterone lowered preterm birth in high-risk pregnancy
About 14 out of 100 women given vaginal progesterone in a randomized, placebo-controlled trial delivered preterm. With placebo, about 29 out of 100 did. The trial followed 142 women in Brazil at high risk of preterm birth. Frequent contractions on weekly one-hour monitoring were also less common.
Delivery before 37 weeks: Vaginal progesterone, 13.8 in 100; Placebo, 28.5 in 100. Source: da Fonseca EB et al., 2003, PMID 12592250.Study at a glance, double-blind, placebo-controlled study of 142 women: Vaginal progesterone lowered preterm birth in high-risk pregnancy. Source: da Fonseca EB et al., 2003, PMID 12592250.
Key Findings
Delivery before 37 weeks occurred in 10 of 72 women given vaginal progesterone (13.8%) and 20 of 70 given placebo (28.5%; P = .03).
Delivery before 34 weeks occurred in 2 of 72 women given progesterone and 13 of 70 given placebo (P = .002).
Frequent uterine contractions on weekly one-hour monitoring were found in 23.6% of the progesterone group and 54.3% of the placebo group (P = .0001).
Admission for threatened preterm labor was 14 of 72 (19.4%) with progesterone and 22 of 70 (31.4%) with placebo, a difference that was not significant.
Interpretation
The trial was randomized, placebo-controlled, and double-blind, at one hospital in Brazil. Women qualified if they had a prior preterm birth, a cervical cerclage, or a uterine malformation. Each day, women used vaginal progesterone or an identical placebo. Neither patients nor staff knew which group was which. The authors call for larger, multicenter trials to confirm the results.
RRM Context
Progesterone is the hormone the ovary makes after ovulation. The trial used natural progesterone. Restorative reproductive medicine draws a line here. Natural progesterone and synthetic progestins are different drugs. Findings on one do not apply to the other.
Our editorial summary of this paper, not the article's abstract.
Abstract
Objective
The purpose of this study was to evaluate the effect of prophylactic vaginal progesterone in decreasing preterm birth rate in a high-risk population.
Study Design
A randomized, double-blind, placebo-controlled study included 142 high-risk singleton pregnancies. Progesterone (100 mg) or placebo was administered daily by vaginal suppository and all patients underwent uterine contraction monitoring with an external tocodynamometer once a week for 60 minutes, between 24 and 34 weeks of gestation. Progesterone (n = 72) and placebo (n = 70) groups were compared for epidemiologic characteristics, uterine contraction frequency, and incidence of preterm birth. Data were compared by chi(2) analysis and Fisher exact test.
Results
The preterm birth rate was 21.1% (30/142). Differences in uterine activity were found between the progesterone and placebo groups (23.6% vs 54.3%, respectively; P <.05) and in preterm birth between progesterone and placebo (13.8% vs 28.5%, respectively; P <.05). More women were delivered before 34 weeks in the placebo group (18.5%) than in the progesterone group (2.7%) (P <.05).
Conclusion
Prophylactic vaginal progesterone reduced the frequency of uterine contractions and the rate of preterm delivery in women at high risk for prematurity.
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