Nearly 12 percent of pregnancies in...

Nearly 12 percent of pregnancies in the United States deduction in birth before 37 weeks' gestation, and the incidence of similar preterm births is slowly increasing. in the greatest degree tocolytic treatments have not been effective beyond 48 hours in clinical trials. common explanation for this apparent lack of impact is that treatment is solitary begun once uterine activity has been confirmed. Sanchez-Ramos and colleagues reviewed the literature in succession an alternative strategy--prophylactic tocolysis using progesterone in women at high risk of preterm labor--to find the effectiveness of progesterone in preventing preterm birth in mothers at elevated risk and the impact of progesterone in succession perinatal morbidity and mortality.

The authors searched electronic databases, abstracts, and bibliographies and contacted dexterouss in the field to identify all relevant studies. Studies included in the analysis had to use an result measure of delivery before 37 weeks' gestation, threatened preterm labor, birth weight les than 2500 g perinatal mortality, or respiratory distress syndrome Studies were independently rated for quality by the agency of two reviewers.

From more than 1600 initial citations, 10 studies met criteria for inclusion in the meta-analysis and listed a total of 1,339 mothers. The principally frequent risk factors among participants were previous preterm birth and multiple spontaneous abortions. The high-risk mothers who received progesterone (of varying types) had significantly lower rates of preterm birth than those randomized to placebo (262 compared with 359 percent; unmatcheds ratio [OR], 0.45; number exigencyed to treat [NNT] to thwart one premature birth = 10) Similar proceeds were found when the most numerous common progesterone, 17alpha-hydroxyprogesterone caproate, was considered alone (NNT = eight). There also was a lower rate of low-birth-weight infants born to mothers treated with this agent (203 compared with 284 percent; OR, 050; NNT = 12) Rates of perinatal mortality were lower in the treated dispose (14.8 compared with 17.1 percent; OR, 069) The incidence of respiratory distress syndrome also was lower (95 compared to 116 percent; OR, 083) nevertheless was not statistically significant. The rates of hospital admission for preterm labor were similar in mothers treated with progesterone and those receiving placebo.

The authors end that preventive therapy with progesterone cut downs preterm birth in mothers at increased risk.

ANNE D WALLING, MD

Sanchez-Ramos L et al. Progestational agents to preclude preterm birth: a meta-analysis of randomized controll trials. Obstet Gynecol February 2005;105:273-9

COPYRIGHT 2005 American Academy of Family Physicians

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