Journal of Medicine and Medical Sciences Vol. 1(3) pp. 083-086 April 2010
Available online http://www.interesjournals.org/JMMS
Copyright ©2010 International Research Journals
Full length Research Paper
Transvaginal ultrasonographic measurement of cervical
and uterine size in varying uterine versions/flexions
Ambrogio P Londero¹, Serena Bertozzi², Arrigo Fruscalzo³
1
Clinic of Obstetrics and Gynecology, University Hospital of Udine, Italy
SSMM Misericordia 15, 33100 Udine, Italy
2
Clinic of Surgical Semeiotics, University Hospital of Udine, Italy
3
Department of Obstetrics and Gynecology, Gesundheitszentrum Rheine - Mathias-Spital, Rheine, Germany
Accepted 02 April, 2010
This study is carried out to assess transvaginal ultrasonographic measurement of uterine and cervical
size in varying uterine versions/flexions. We compared 28 transvaginal ultrasonographic measurements
of the cervix and uterus on one patient with Allan-Master’s syndrome. Statistical analysis was
performed by R (version 2.8.0), considering significant a p<0.05; Anova Oneway, Tukey test, and t-test
were used to compare mean values, and Kolmogorov-Smirnov test to state the normality of all
considered variables. Uterus was anteverted on 9 occasions, retroverted on 15 and on axis on 4. Mean
cervical length and width results significantly greater by the anteverted uterus than by the retroverted
one (p<0.05).There is a significant difference of cervical size based on its position and on uterus
versions-flexions and we have to take in consideration a possible underestimation of cervical length
with retroverted uterus.
Keywords: Cervix measurement, retroverted uterus, transvaginal ultrasonography.
INTRODUCTION
The literature demonstrates that transvaginal ultrasonography is a good method to estimate cervical length,
and it is more precise than vaginal visits (Jackson et al.,
1992). It may be used to predict the risk of preterm delivery, labour induction failure or caesarean section requirement. Moreover, it may be useful for the surgeon to
predict the difficulties of transvaginal or transabdominal
histerctomy.
While cervical size at mid- or last gestation is a recognized predictive factor for preterm labour (Theron et al.,
2008; Smith et al.,2008; Ozdemir et al., 2007), but the
literature lacks in studies about the cervical size at initial
gestation or in non pregnant women. Furthermore, we did
not find in the literature studies about estimation of
cervical length in retroverted uterus.
Our study then aims to assess transvaginal ultrasonographic measurement of uterine and cervical size in
varying uterine versions/flexions.
*Corresponding author email: ambrogio.londero@gmail.com;
Tel: 0039-0432-559635; Fax: 0039-0432-559641; Cel: 0039347-2335937
MATERIALS AND METHODS
We collected data about transvaginal ultrasonographic measurements on the same patient found to be affected by uterus
hypermobility. This diagnosis was made by finding the uterous in
previous ultrasonographies antevertedflexed in some occasions
and retrovertedflexed in some others, and sometimes it was also
possible to observe the uterus during the same ultrasound examination varying between the anteverted flexed and the retroverted
flexed position.
Within two consecutive menstrual cycles, uterus and cervix size
were measured every second day (starting from the first day of the
first cycle) on a 25-years-old caucasian nullipara nulligravida with
uterine hypermotility and regular menstrual cycles lasting 29 days
with 5 days of bleeding.
All ultrasonographic measurements were performed by the same
operator with an Acuson Sequoia 512 Sonographer with a transvaginal probe (EV8C4).
Cervical length was measured as the linear distance between the
internal, cervical orifice (considered to be the point where endometrium finishes) and the external one, while the whole length of
the cervical canal could be observed, thus a symmetric image of the
external one can be obtained. Cervical width was measured at the
maximal wide point of the cervix along the cervical canal. Uterine
length was measured in one segment, in anterior-posterior view
from the fundus to the cervix, comprising the whole cervix. In addition, curve lengths were measured as a single linear segment.
084 J. Med. Med. Sci.
Figure 1. Two images of the same uterus: one anteverted flexed
and one retroverted flexed.
Table 1. Uterus measurments by every different uterine position: variance analysis by One-way Anova (values represent mean
and standard deviation).
Cervical length
Cervical width
Uterus length
Uterus width
Anteverted flexed
32.12 (±2.37)
22.48 (±1.6)
75.21 (±2.03)
38.28 (±1.25)
On axis
27.2 (±2.12)
25.05 (±4.07)
74 (±1.63)
37.5 (±0.58)
Statistical analysis was performed by R (version 2.8.0), considering significant a p<0.05. Oneway Anova, Tukey Honest Significant Differences, and t-test were used to compare mean values,
and Kolmogorov-Smirnov test to state the normality of all considered variables.
RESULTS
Uterus was anteverted flexed on 9 occasions, retroverted
flexed on 15, and on axis (not verted nor flexed) on the
remaining 4 (Figure 1).
Table 1 shows the mean cervical length and its standard deviation by each uterine position. Comparing mean
cervical length and width in the different uterine positions,
Retroverted flexed
26.76 (±3.8)
25.43 (±3.82)
68.15 (±1.88)
38.4 (±1.88)
p
<0.05
0.122
<0.05
0.605
they result significantly greater by an anteverted flexed
uterus than by a retroverted flexed one (p<0.05), and
there is also a significant difference of mean length
between an antevertedflexed and an on axis uterus
(p<0.05) (Figure 2).
Uterus length estimation in anteverted position or on
axis position is statistically longer then in retroverted
position (p<0.05), while no significant difference has been
observed between anteverted uterus and that on axis.
Moreover, the uterus width measures show no
significant difference between the anteverted position of
the uterus, the retroverted one or that on axis.
Then, considering that the cervix does not significantly
change during cycle and thus in this case we succeed in
Londero et al. 085
Figure 2. The mean cervical length with 95% confidence intervals, in the three
different positions.
excluding all possible variability sources, as the measurements were done on the same cervix by the same
gynaecologist and with the same machine, our results
suggest a significant difference of the cervical size based
on its position and on uterus version-flexion.
DISCUSSION
Uterine hypermotility is a rare condition, firstly described
by Allen and Masters as an intraoperatively diagnosed
syndrome characterized by lacerations in the peritoneum
and fascia of the broad and cardinal ligaments. These
kind of lacerations are described in both multiparous and
nulliparous patients, but are mostly associated with
pregnancy (Ventolini and Neiger, 2007). We observed a
young nullipara nulligravida with uterine hypermotility of
casual ultrasonographic diagnose.
The literature demonstrates the ultrasonographic measurment of cervix to be an accurate method to estimate
the cervical length in the case of anteverted uterus
(Jackson et al., 1992), but also admits an underestimation of ultrasonographic measurement in the case of
curved cervix (To et al., 2001).With our case, we demostrate the significant difference between the estimation of
cervical length in anteverted and retroveted position of
the uterus, in the same patient and consequently the
same cervix.
Although we cannot yet surely say if there is an overestimation of cervical length by means of an anteverted
flexed uterus or an under-estimation due to a retroverted
flexed one, we can suppose an underestimation of
cervical length in retroverted uterus position, because of
a more important curvature of the cervix in the most
occasions of retroverted uterus.
In the literature no static evaluation of cervical length
has been able to identify yet the women who have delivered preterm or that will be at risk for preterm delivery
(Pardo et al., 2003), and actually we think that a dynamic
evaluation of cervix during early pregnancy would be
more appropriate in this perspective. In fact, based on
previous studies (Londero et al., 2010; Berghella et al.,
2003), we suppose that in the first part of pregnancy
there is a dynamic evolution of cervix, and in particular
that the cervical length progressively increases due to
physiologic modifications (Zemlyn, 1981). Therefore, it is
important to acknowledge such an evolution in order to
critically evaluate cervical length by predicting the risk of
preterm delivery in case of a retroverted flexed uterus.
The difference observed between the uterus length between the anteverted and the retroverted position may be
interpreted in the same way as cervical length in these
086 J. Med. Med. Sci.
positions, and we consequently suppose an underestimation also of uterus length in its retroverted position.
An important limitation of our study is that we evaluated
a single patient, and this it is due to the rarity of the clinical characteristics of the observed patient. On the other
hand, this limitation represents also a strength point of
our research, because we could exclude every biological
variation of cervical length, which may exist between the
different individuals. Moreover, we took in consideration
every factor which may affect measurement variability,
such as uterine position and cycle phase, and we reduced every possible confounding factor such as
operator or machine variability. In particular, we choose a
single operator and a standard method to measure the
cervix, even if we did not test the inter-operator variability
of measurements, because the main aim of the study
was to test the differences in estimation of cervical length
by changing the uterus position.
Conclusion
In conclusion, we found a significant difference of cervical
size based on its position and on uterus version-flexions,
which suggests a possible under-estimation of cervical
length in case of retroverted uterus.
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