BackgroundIn singleton gestations,

Background
In singleton gestations, 17 alpha-hydroxyprogesterone caproate (17P) has been shown
to reduce the rate of recurrent preterm birth. This study was undertaken to evaluate
whether 17P would reduce the rate of preterm birth in twin gestations.
Methods
We performed a randomized, double-blind, placebo-controlled trial in 14 centers.
Healthy women with twin gestations were assigned to weekly intramuscular injections
of 250 mg of 17P or matching placebo, starting at 16 to 20 weeks of gestation
and ending at 35 weeks. The primary study outcome was delivery or fetal death before
35 weeks of gestation.
Results
Six hundred sixty-one women were randomly assigned to treatment. Baseline demographic
data were similar in the two study groups. Six women were lost to follow-
up; data from 655 were analyzed (325 in the 17P group and 330 in the placebo
group). Delivery or fetal death before 35 weeks occurred in 41.5% of pregnancies in
the 17P group and 37.3% of those in the placebo group (relative risk, 1.1; 95% confidence
interval [CI], 0.9 to 1.3). The rate of the prespecified composite outcome of
serious adverse fetal or neonatal events was 20.2% in the 17P group and 18.0% in
the placebo group (relative risk, 1.1; 95% CI, 0.9 to 1.5). Side effects of the injections
were frequent in both groups, occurring in 65.9% and 64.4% of subjects, respectively
(P = 0.69), but were generally mild and limited to the injection site.
Conclusions
Treatment with 17 alpha-hydroxyprogesterone caproate did not reduce the rate
of preterm birth in women with twin gestations. (ClinicalTrials.gov number,
NCT00099164.)

Results (English) 3:

在单胎妊娠的背景
，17α-羟基己酸（17p）已被证明
降低早产率。本研究的目的是评估是否会降低
17p的双胞胎早产率。
方法
我们进行了一项随机，双盲，安慰剂对照试验在14个中心。
与双胎妊娠的健康妇女被分配到每周肌肉注射250毫克的
17P或匹配的安慰剂，在16至20周的妊娠
的开始和结束在35周。主要研究结果
妊娠35周前分娩或胎儿死亡。
结果
六百六十一名妇女被随机分配到治疗。基线人口统计学
数据在两组相似。六名妇女失去了后续
起来；分析了数据从655（325在17p组和330安慰剂
组）。在
17p组和安慰剂组37.3%例妊娠41.5%发生分娩前35周或胎儿死亡（相对风险，1.1；95%可信区间[CI]
，0.9到1.3）。
严重的胎儿和新生儿的事件为20.2%，在安慰剂组
17P和18%个预先设定的复合结果率（相对风险，1.1；95% CI，0.9 - 1.5）。
注射的副作用在两组频繁，在65.9%和64.4%的患者出现
，分别为（P = 0.69），但通常是温和的和有限的注射部位。
结论
17α-羟基己酸治疗并不能降低早产与双胎妊娠妇女的出生率
。（ClinicalTrials.gov，
nct00099164。）