Application value of ultrasound elastography for screening of early pregnancy cervical insufficiency: a retrospective case-control study

Figures & data

Figure 1. Schematic Of cervical elastography ROI localization with dual-mode grey-scale ultrasound images (left) and real-time elastography (right).

Figure 2. Schematic Diagram of uterine artery RI measurement.

Table 1. Maternal characteristics and neonatal outcomes of the study group.

	Cervical insufficiency (n = 60)	No cervical insufficiency (n = 100)	p value
Mother Age (y)	33.40 ± 3.82	32.91 ± 3.56	.414
BMI (kg/m^2)	23.59 ± 2.77	22.87 ± 2.29	.064
Gravida	3 (2–7)	2 (1–4)	<.001*
Para	0 (0–2)	0 (0–2)	0.184
Neonate
Delivery age (wk)	37.5(28.4–39.5)	38.6 (36.1–41.0)	<.001*
Birthweight (g)	2979.62 ± 513.34	3345.30 ± 288.94	<.001*
Apgar scores
Apgar scores < 9 at 1 min	23 (38%)	12 (12%)	<.001*
Apgar scores ≤ 9 at 5 min	8 (13%)	6 (6%)	.112

Continuous variables with normal distribution are expressed as mean ± standard deviation and continuous variables with skewed distribution are expressed as median (minimum, maximum). BMI: body mass index.

* p < .05 was considered statistically significant.

Table 2. Cervical elastography, cervical length and arteria uterina RI width of the study group.

	Cervical insufficiency (n = 60)	No cervical insufficiency (n = 100)	p value
GA at scan (weeks)	12.28 ± 0.61	12.27 ± 0.64	.879
CRL (mm)	58.77 ± 5.93	58.51 ± 6.09	.795
Strain rate (%)
SRI	0.19 ± 0.018	0.16 ± 0.014	<.001*
SRE	0.26 ± 0.028	0.24 ± 0.025	.002*
Cervical length (mm)	34.3 ± 2.91	35.2 ± 1.99	.036*
arteria uterina RI	0.76 ± 0.07	0.74 ± 0.05	.048*

Continuous variables are presented as mean ± standard deviation. CRL: crown-lump length; GA: gestational age; SR_I: the strain rate of the internal cervical opening; SR_E: the strain rate of the external cervical opening.

* p < .05 was considered statistically significant.

Figure 3. Box-And-whisker plots of (A) the strain rate of the internal cervical opening, (B) the strain rate of the external cervical opening, (C) cervical length and (D) arteria uterina RI between the cervical insufficiency and no cervical insufficiency groups.

Figure 4. Subject work characteristics (ROC) curves and area under the curve (AUC) for the strain rate of the internal cervical opening, the strain rate of the external cervical opening, cervical length, uterine artery RI and the combination of these five parameters predicting cervical insufficiency of 0.89, 0.66, 0.59, 0.59, 0.59 and 0.92, respectively.

Table 3. ROC curve analyses of cervical elastography, cervical length, and arteria uterina RI width for the diagnosis of cervical insufficiency.

	Cut-off value	AUC	95% CI	Sensitivity	Specificity	p value
(1) SRI	0.17%	0.89	0.83–0.94	0.78	0.82	0.000*
(2) SRE	0.25%	0.66	0.57–0.75	0.62	0.68	0.001*
(3)Cervical length (mm)	33.8	0.59	0.50–0.69	0.48	0.75	0.045*
(4) arteria uterina RI	0.78	0.59	0.50–0.70	0.45	0.80	0.039*
(1) + (2) + (3) + (4)		0.92	0.88–0.97	0.80	0.91	0.000*

AUC: area under the curve; CI: confidence interval; ROC: receiver operating characteristic.

* p < .05 was considered statistically significant.

Table 4. Univariate and multivariate logistic regression analyses of individual parameter related to cervical insufficiency.

	Univariate logistic regression			Multivariate logistic regression
Parameter	Unadjusted OR	95% CI	p value	Unadjusted OR	95% CI		p value
Gravida	3.257	2.146–4.943	<.001*	3.976	2.183–7.241		<.001*
SRI
≥ 0.17%	16.470	7.412–36.597	<.001*	17.474	5.082–60.085		<.001*
< 0.17%	1
SRE
≥ 0.25%	3.418	1.751–6.673	<.001*	0.639	0.192–2.124		.465
< 0.25%	1
Cervical length
≤ 33.8 mm	2.806	1.423–5.535	.003*	5.054	1.667–15.326		.004*
> 33.8 mm	1
arteria uterina RI
≥ 0.78	3.273	1.615–6.632	.001*	2.464	0.903–6.718		.078
< 0.78	1

CI: confidence interval; OR: odds ratio.

* p < .05 was considered statistically significant.

Data availability statement

The datasets used during the current study are available from the corresponding author on reasonable request.