宫颈长度与自然早产风险。美国国立儿童健康与人类发展研究所母胎医学单位网络。

The length of the cervix and the risk of spontaneous premature delivery. National Institute of Child Health and Human Development Maternal Fetal Medicine Unit Network.

作者信息

Iams J D, Goldenberg R L, Meis P J, Mercer B M, Moawad A, Das A, Thom E, McNellis D, Copper R L, Johnson F, Roberts J M

机构信息

Department of Obstetrics and Gynecology, Ohio State University, Columbus, USA.

出版信息

N Engl J Med. 1996 Feb 29;334(9):567-72. doi: 10.1056/NEJM199602293340904.

DOI:10.1056/NEJM199602293340904

PMID:8569824

Abstract

BACKGROUND

The role of the cervix in the pathogenesis of premature delivery is controversial. In a prospective, multicenter study of pregnant women, we used vaginal ultrasonography to measure the length of the cervix; we also documented the incidence of spontaneous delivery before 35 weeks' gestation.

METHODS

At 10 university-affiliated prenatal clinics, we performed vaginal ultrasonography at approximately 24 and 28 weeks of gestation in women with singleton pregnancies. We then assessed the relation between the length of the cervix and the risk of spontaneous preterm delivery.

RESULTS

We examined 2915 women at approximately 24 weeks of gestation and 2531 of these women again at approximately 28 weeks. Spontaneous preterm delivery (at less than 35 weeks) occurred in 126 of the women (4.3 percent) examined at 24 weeks. The length of the cervix was normally distributed at 24 and 28 weeks (mean [+/- SD], 35.2 +/- 8.3 mm and 33.7 +/- 8.5 mm, respectively). The relative risk of preterm delivery increased as the length of the cervix decreased. When women with shorter cervixes at 24 weeks were compared with women with values above the 75th percentile, the relative risks of preterm delivery among the women with shorter cervixes were as follows: 1.98 for cervical lengths at or below the 75th percentile (40 mm), 2.35 for lengths at or below the 50th percentile (35 mm), 3.79 for lengths at or below the 25th percentile (30 mm), 6.19 for lengths at or below the 10th percentile (26 mm), 9.49 for lengths at or below the 5th percentile (22 mm), and 13.99 for lengths at or below the 1st percentile (13 mm) (P < 0.001 for values at or below the 50th percentile; P = 0.008 for values at or below the 75th percentile). For the lengths measured at 28 weeks, the corresponding relative risks were 2.80, 3.52, 5.39, 9.57, 13.88, and 24.94 (P < 0.001 for values at or below the 50th percentile; P = 0.003 for values at the 75th percentile).

CONCLUSIONS

The risk of spontaneous preterm delivery is increased in women who are found to have a short cervix by vaginal ultrasonography during pregnancy.

摘要

背景

宫颈在早产发病机制中的作用存在争议。在一项针对孕妇的前瞻性多中心研究中，我们使用阴道超声测量宫颈长度；我们还记录了妊娠35周前自然分娩的发生率。

方法

在10家大学附属医院的产前诊所，我们对单胎妊娠的女性在妊娠约24周和28周时进行阴道超声检查。然后我们评估宫颈长度与自然早产风险之间的关系。

结果

我们在妊娠约24周时检查了2915名女性，其中2531名女性在妊娠约28周时再次接受检查。在24周时接受检查的女性中有126名（4.3%）发生了自然早产（妊娠不足35周）。宫颈长度在24周和28周时呈正态分布（均值[±标准差]分别为35.2±8.3mm和33.7±8.5mm）。早产的相对风险随着宫颈长度的缩短而增加。将24周时宫颈较短的女性与宫颈长度高于第75百分位数的女性进行比较时，宫颈较短的女性早产的相对风险如下：宫颈长度在第75百分位数及以下（40mm）时为1.98，在第50百分位数及以下（35mm）时为2.35，在第25百分位数及以下（30mm）时为3.79，在第10百分位数及以下（26mm）时为6.19，在第5百分位数及以下（22mm）时为9.49，在第1百分位数及以下（13mm）时为13.99（第50百分位数及以下的值P<0.001；第75百分位数及以下的值P=0.008）。对于在28周时测量的长度，相应的相对风险分别为2.80、3.52、5.39、9.57、13.88和24.94（第50百分位数及以下的值P<0.001；第75百分位数的值P=0.003）。