Re: Short Cervix
From: Charlie Chambers (cchamber@gorge.net)
Sun Oct 13 13:52:59 2002
Does she have any other deliveries? Any other risk factors?
On Sunday, October 13, 2002, at 08:09 AM, Dean Huffman wrote:
>
> What do the members of this list do for a patient who has a short
> cervix in the mid trimester, e.g., a cervix less than 25 mm. at 16 - 18
> weeks?
>
> See:
>
> JAMA 2001 Sep 19;286(11):1340-8, Mid-trimester endovaginal sonography
> in women at high risk for spontaneous preterm birth. Owen J, Yost N,
> Berghella V, Thom E, Swain M, Dildy GA 3rd, Miodovnik M, Langer O,
> Sibai B, McNellis D; National Institute of Child Health and Human
> Development, Maternal-Fetal Medicine Units Network.
>
> CONTEXT: Although shortened cervical length has been consistently
> associated with spontaneous preterm birth, it is not known when in
> gestation this risk factor becomes apparent.
>
> OBJECTIVE: To determine whether sonographic cervical findings between
> 16 weeks' and 18 weeks 6 days' gestation predict spontaneous preterm
> birth and whether serial evaluations up to 23 weeks 6 days' gestation
> improve prediction in high-risk women.
>
> DESIGN, SETTING, AND PARTICIPANTS: Blinded observational study
> performed between March 1997 and November 1999 at 9
> university-affiliated medical centers in the United States in 183 women
> with singleton gestations who previously had experienced a spontaneous
> birth before 32 weeks' gestation.
>
> OBSERVATION: Certified sonologists performed 590 endovaginal
> sonographic examinations at 2-week intervals. Cervical length was
> measured from the external os to the functional internal os along a
> closed endocervical canal. Funneling and dynamic cervical shortening
> were also recorded.
>
> MAIN OUTCOME MEASURE: Spontaneous preterm birth before 35 weeks'
> gestation, analyzed by selected cutoff values of cervical length.
>
> RESULTS: Forty-eight women (26%) experienced spontaneous preterm birth
> before 35 weeks' gestation. A cervical length of less than 25 mm at the
> initial sonographic examination was associated with a relative risk
> (RR) for spontaneous preterm birth of 3.3 (95% confidence interval
> [CI], 2.1-5.0; sensitivity = 19%; specificity = 98%; positive
> predictive value = 75%). After controlling for cervical length, neither
> funneling (P =.24) nor dynamic shortening (P =.054) were significant
> independent predictors of spontaneous preterm birth. However, using the
> shortest ever observed cervical length on serial evaluations, after any
> dynamic shortening, the RR of a cervical length of less than 25 mm for
> spontaneous preterm birth increased to 4.5 (95% CI, 2.7-7.6;
> sensitivity = 69%; specificity = 80%; positive predictive value = 55%).
> Compared with a single cervical measurement at 16 weeks' to 18 weeks 6
> days' gestation, serial measurements at up to 23 weeks 6 days
> significantly improved the prediction of spontaneous preterm birth in a
> receiver operating characteristic curve analysis (P =.03).
>
> CONCLUSIONS: Cervical length assessed by endovaginal sonography between
> 16 weeks' and 18 weeks 6 days' gestation, augmented by serial
> evaluations, predicts spontaneous preterm birth before 35 weeks'
> gestation in high-risk women.
>
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Charlie Chambers
--
Hood River, OR USA
cchamber@alumni.rice.edu
"...not because I regard fishing as being so terribly
important but because I suspect that so many of the other
concerns of men are equally unimportant-and not nearly
so much fun."
John Voelker
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