研究背景

随机研究表明对有既往早产史的孕妇使用孕酮可降低其再次妊娠时早产发生率；若孕妇中孕期间宫颈长度过短则可使早早产风险大为增加，目前孕酮是否可降低此风险仍有待研究。

方法
于常规产前检查时以阴道超声测定24,620名孕妇中孕（孕周中位数22w）宫颈长度，取413例（1.7％）宫颈长度＜15mm者为研究对象。随机分组以其中250例对象（60.5％）为干预组、其余163例对象（39.5％）为对照组；在孕24～34w时干预组对象每晚给予孕酮200mg、对照组对象则给予安慰剂。主要观察指标为对象之胎儿是否于孕34w前自然娩出（早早产）。

结果
干预组对象早早产率低于观察组（19.2％vs. 34.4％，RR:0.56，95％CI: 0.36～0.86）；干预组新生儿死亡率略低，但无统计学意义（8.1％vs. 13.8％，RR:0.59，95％CI: 0.26～1.25，P=0.17）。干预组对象使用孕酮后未发生严重副反应。

结论
孕酮治疗可降低中孕宫颈过短孕妇早早产发生率。（临床试验注册号：NCT00422526）

（以上译文由上海国际妇幼和平医院朱昊平大夫提供）

英文原文：

Progesterone and the Risk of Preterm Birth among Women with a Short Cervix
Eduardo B. Fonseca, M.D., Ebru Celik, M.D., Mauro Parra, M.D., Mandeep Singh, M.D., and Kypros H. Nicolaides, M.D., for the Fetal Medicine Foundation Second Trimester Screening Group*

BACKGROUND
Previous randomized trials have shown that progesterone administration in women
who previously delivered prematurely reduces the risk of recurrent premature delivery.
Asymptomatic women found at midgestation to have a short cervix are at greatly
increased risk for spontaneous early preterm delivery, and it is unknown whether
progesterone reduces this risk in such women.
METHODS
Cervical length was measured by transvaginal ultrasonography at a median of 22
weeks of gestation (range, 20 to 25) in 24,620 pregnant women seen for routine
prenatal care. Cervical length was 15 mm or less in 413 of the women (1.7%), and
250 (60.5%) of these 413 women were randomly assigned to receive vaginal progesterone
(200 mg each night) or placebo from 24 to 34 weeks of gestation. The primary
outcome was spontaneous delivery before 34 weeks.
RESULTS
Spontaneous delivery before 34 weeks of gestation was less frequent in the progesterone
group than in the placebo group (19.2% vs. 34.4%; relative risk, 0.56; 95%
confidence interval [CI], 0.36 to 0.86). Progesterone was associated with a nonsignificant
reduction in neonatal morbidity (8.1% vs. 13.8%; relative risk, 0.59; 95% CI,
0.26 to 1.25; P = 0.17). There were no serious adverse events associated with the use
of progesterone.
CONCLUSIONS
In women with a short cervix, treatment with progesterone reduces the rate of spontaneous
early preterm delivery. (ClinicalTrials.gov number, NCT00422526.)