Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands.
Ultrasound Obstet Gynecol. 2012 Oct;40(4):426-30. doi: 10.1002/uog.11174.
Previous studies on singleton pregnancies have indicated that progestogens may reduce the rate of cervical shortening during pregnancy. The aim of this study was to investigate whether treatment with 17-alpha hydroxyprogesterone caproate (17-OHPC) has an effect on cervical shortening in twin pregnancies.
This was a secondary analysis of patients who had participated in a multicenter randomized clinical trial on the effectiveness of 17-OHPC in preventing preterm birth in multiple pregnancies (the AMPHIA-trial). We included all trial participants with a twin gestation who had undergone repeat cervical length measurements during pregnancy. We performed a separate analysis of women with repeat measurements in centers where this was standard protocol for multiple pregnancies. The rate of cervical shortening for both the 17-OHPC group and the placebo group was analyzed using a linear mixed model.
Of the 671 patients who participated in the trial, 282 (42%) had a twin pregnancy and underwent two or more cervical length measurements. Of these women, 140 were monitored in centers where repeat measurements were standard protocol. We observed an overall reduction of cervical length from 44.3 mm at 14-18 weeks to 30.0 mm at 30-34 weeks' gestation. In the 17-OHPC group, cervical length decreased by 1.04 mm each gestational week, while this was 1.11 mm per week for the placebo group (P = 0.6). For the overall group, each 10% decrease in cervical length led to an increase in the risk of preterm birth (hazard ratio, 1.14; 95% CI, 1.08-1.21).
In women with a twin pregnancy, there is progressive shortening of the cervix during pregnancy, regardless of 17-OHPC use.
先前对单胎妊娠的研究表明，孕激素可能会降低妊娠期间宫颈缩短的发生率。本研究旨在探讨 17-α 羟孕酮己酸酯（17-OHPC）治疗是否会对双胎妊娠的宫颈缩短产生影响。
这是一项对参与多中心随机临床试验的患者进行的二次分析，该试验研究了 17-OHPC 在预防多胎妊娠早产中的有效性（AMPHIA 试验）。我们纳入了所有接受过重复宫颈长度测量的多胎妊娠试验参与者。我们对那些在多胎妊娠标准方案中进行重复测量的中心的女性进行了单独分析。使用线性混合模型分析 17-OHPC 组和安慰剂组的宫颈缩短率。
在参与试验的 671 名患者中，282 名（42%）患有双胎妊娠，并进行了两次或更多次宫颈长度测量。在这些女性中，有 140 名在重复测量是多胎妊娠标准方案的中心进行监测。我们观察到，从 14-18 周的 44.3 毫米到 30-34 周的 30.0 毫米，宫颈长度总体减少。在 17-OHPC 组中，宫颈长度每妊娠周减少 1.04 毫米，而安慰剂组为每 1.11 毫米/周（P = 0.6）。对于整个组，宫颈长度每减少 10%，早产的风险增加 1.14 倍（危险比，1.14；95%可信区间，1.08-1.21）。
在双胎妊娠女性中，无论是否使用 17-OHPC，妊娠期间宫颈都会逐渐缩短。
