DSJUOG

10.5005/jp-journals-10009_1524
Cervical Incompetence: Modern Clinical Protocols and Real Practice
Review Article

Cervical Incompetence: Modern Clinical Protocols and

Real Practice
1
Larisa D Belotserkovtseva, 2Ludmila V Kovalenko, 3Sergey E Ivannikov, 4Gulnora T Mirzoeva, 5Tatiana G Petrova

ABSTRACT INTRODUCTION
Objective: The objective is to evaluate efficiency of using inter- Frequency of PB rises almost in all countries in the world,
nal protocol of prophylaxis preterm birth (PB).
making nowadays more than 10% of all deliveries.
Materials and methods: Three hundred and seventy gravidas Prematurity and complications connected with it are the
without clinical symptoms of preterm delivery with cervical canal
main reasons of neonatal death rate (during first 4 weeks
length of <25 mm and on <21 gestation weeks were inspected.
Protocol included anamnesis research, 200 mg of daily vaginal of life) and are also the second most important reason of
progesterone, ultrasound monitoring of length and shape of pneumonia death rate among children under the age of 5.1
cervical canal, and distinguished treatment of cervical insuf- There are a lot of reasons for PB, and not all of them are
ficiency using cerclage or cervical pessary. quite obvious. At the same time, factors, such as burden
Results: Gravidas whose protocol was fully attended have reproductive history (unprompted PB in anamnesis or
more than dual-fold decrease of extra early preterm delivery usage of auxiliary reproductive technologies)2,3 and
risk ratio [4.3 vs 12.3% relative risk (RR) 0.47; 95% confidence
shortening of uterine cervix (cervical insufficiency)4,5 are
interval (CI) 0.23–0.99], compared with those whose protocol
was attended fractionary. Quantity of unprompted miscarriages very important in causing PB.
in 22+0 week period also decreased dual-fold (6.6 vs 13.8%; RR Confidence interval with little frequency in popula-
0.47; 95% CI 0.23–0.99). The most common mistakes were tion (about 1%) is estimated as significant threat by many
ignorance of anamnesis data, wrong choice of ways of correction
researchers.5-7 According to Heath VC (1998)5 length
cervical insufficiency, long and ineffective treatment of genital
tract infections, and inaccurate estimation of cervical canal. of uterine cervix on 23rd gestation week, i.e., ≤15 mm
is encountered in <2% of all pregnancies (43 of 2,567);
Summary: Usage of effective medication, development of new
clinical protocols, and detailed abidance of earlier accepted meanwhile, these gravidas are approximately 90 and
protocols, mistakes’ analysis, and staff training are reserves of 60% of all amount of women with unprompted PB in
extremely PB decrease. accordance with <28 and <32 weeks gestation period.5
Keywords: Cervical cerclage, Cervical incompetence, Cervical Sizing length of cervical canal among gravidas, who
pessary, Clinical protocol, Preterm delivery, Ultrasound gained PB treatment, allowed distinguishing vera and
cervicometry. spuria labor: Unprompted delivery within 7 days hap-
How to cite this article: Belotserkovtseva LD, Kovalenko LV, pened to 40% of those who had cervical canal length
Ivannikov SE, Mirzoeva GT, Petrova TG. Cervical Incompetence: <14 mm, and to <1% of those whose cervical canal
Modern Clinical Protocols and Real Practice. Donald School
length was >15 mm.6 Length of uterine cervix ≤25 mm
J Ultrasound Obstet Gynecol 2017;11(3):203-209.
is positively connected with earlier gestation age during
Source of support: Nil repeated PB in <37, 35, 34, and 32 weeks of gestation
Conflict of interest: None period.7
Precise supersonic sizing of uterine cervix has reverse
1,2
casualty with PB risk.8 The most precise method of sizing
Professor, 3Associate Professor, 4,5Head
length of cervical canal is usage of transvaginal super-
1,3
Department of Obstetrics, Gynecology and Perinatology sonic detector. Patients must have empty urinary bladder;
Institute of Medicine, Surgut State University, Surgut, Russian
Federation vaginal detector must be put in front arch of vagina in
2 order to minimize pressure on uterine cervix as long as it
Institute of Medicine, Surgut State University, Surgut, Russian
Federation increases cervix’s length. Length of cervical canal should
4
Department of Obstetrics Pregnancy Failure, Surgut Clinical
be measured straight from external to internal mouth of
Perinatal Center, Surgut, Russian Federation uterine cervix. Since state of uterine cervix is dynamic, it
5
Department of Ultrasound Inspection, Surgut Clinical Perinatal is needed to accomplish three measures within 5 minutes5
Center, Surgut, Russian Federation (Fig. 1).
Corresponding Author: Larisa D Belotserkovtseva, Professor When CI is disclosed, there are several ways of pro-
Department of Obstetrics, Gynecology and Perinatology phylaxis of preterm delivery: Progesterone usage, cervical
Institute of Medicine, Surgut State University, Surgut, Russian cerclage, or obstetrics pessary. Systematic review by Dodd
Federatione-mail: glav_kpc@admsurgut.ru
et al,9 which was published in 2013, summarized positive
Donald School Journal of Ultrasound in Obstetrics and Gynecology, July-September 2017;11(3):203-209 203
Larisa D Belotserkovtseva et al

A B
Figs 1A and B: Cervicometry of non state

effects of progesterone. For example, among women Meanwhile, in a randomized clinical research by Hui
with shortened uterine cervix (disclosed via ultrasound et al,14 prophylaxis usage of cervical pessary did not
investigation) compared with placebo, progesterone reduce the decrease of PB quantity in period <34 weeks
associated with statistically authentic decrease risk of among obscure Chinese women with low-risk singlet
PB in period before 34 weeks (RR 0.64, 95% CI 0.45–0.90) pregnancy and uterine cervix length <25 mm in 20 to
and 28 weeks (RR 0.59, 95% CI 0.37–0.93). In group of 24 weeks gestation period.
women with unprompted PB in anamnesis usage of Diversity of data leads to usage of different patient
progesterone compared with placebo led to statistically management protocols among connatural patient cat-
authentic decrease risk of perinatal death (RR 0.50, 95% egory. Comparison of three management guidelines of
CI 0.33–0.75) with PB before 34 weeks (RR 0.31, 95% CI women with singlet pregnancy, PB in <34 weeks in anam-
0.14–0.69), transfer neonates in intensive care unit (RR nesis, and shortened uterine cervix showed congenial
0.24, 95% CI 0.14–0.40), and usage of artificial pulmonary perinatal outcomes.15 This research included 142 women
ventilation (RR 0.40, 95% CI 0.18–0.90). with cerclage (USA), 59 who got vaginal progesterone
Grounds for CI correction are not detailed nowa- (UK), and 42 with cervical pessary (Spain).
Therefore, the choice of optimal way of managing
days and data about its efficiency are controversial. For
patients with CI is an issue that needs discussion nowa-
instance, the research of Nicolaides et al10 showed low
days. In every facility, choice of optimal management is
effectiveness of cervical cerclage in cases of shortened
predicated upon its own policy, results, and developed
uterine cervix. Berghella et al,11 in contrast, reported
management guidelines.
about significant decrease of quantity of PB in <35 weeks
The objective of this research is to evaluate efficiency
period, during usage of cerclage among gravidas with
of usage of internal preterm delivery prophylaxis proto-
uterine cervix length <25 mm and PB in anamnesis. Some
col. Research was made at the premises of Surgut Clinical
specialist consider that cerclage usage can be more vital
Perinatal Center (SCPC) from January 2011 to December
to decrease PB quantity than progesterone usage.12
2014. The SCPC is a huge regional health facility with
Cervical incompetence correction via pessary is a annual delivery quantity more than 9,000. Share of
simple and less-invasive procedure, which does not preterm delivery was 6.1% in 2014.
require anesthesia and can replace cervical cerclage Clinical protocol of prophylaxis of PB is implemented
surgery. Goya et al13 did randomized clinical research since 2011.16 Key statements of protocol are:
among 358 gravidas with uterine cervix length ≤25 mm • Detachment of risk group with PB based on presence
and gestation period from 18 to 22 weeks. Pessary usage of unprompted termination of pregnancy in gestation
(192 women) leads to statistically significant decrease of period from 14+0 to 33+6 weeks, previous cerclage in
PB both in <37 weeks gestation period and in <34 weeks cases of asymptomatic shortening, dilation of uterine
(22 vs 59%; RR 0.36, 95% CI 0.27–0.49) and (6 vs 27%, cervix, and with three or more cases of curettage of
RR 0.24; 95% CI 0.13–0.43) respectively compared with uterine cavity in anamnesis.
expectant management. At the same time, measurable • Sizing of length and shape of cervical canal via
reduction of neonatal help expenses was mentioned in transvaginal ultrasound investigation among gravi-
group, which used pessary compared with group, where das without risk factors in gestation period of 12 to
pessary was not used. 14 and 18 to 21 weeks and in gravidas with risk and

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Cervical Incompetence: Modern Clinical Protocols and Real Practice

A
Fig. 2: Shortening of cervical canal’s length, V-shaped widening
of internal mouth

who have weekly monitoring in gestation period from

14 to 18 weeks.
• Prescription of vaginal progesterone (200 mg capsules
of micronized progesterone in PB risk group).
• In case of disclose of shortening of cervical canal <25
mm before 22rd week, several options are used:
– Inspection of presence of urogenital infection, and
treatment given if necessary;
– Cerclage for high-risk group; B
– Cervical pessary if anamnesis does not include
miscarriage;
– Prescription of vaginal progesterone.
• Ultrasound control is not required after CI correction.
• Removal of cerclage suture or cervical pessary takes
place in the period of 36 to 37 gestation weeks if there
is no fetomaternal disease or in case of painful uterine
retractions and changings of uterine cervix or blood-
tinged discharge.
Research included 370 gravidas without pain com-
plaints, with length of cervical canal <25 mm in gestation
period from 14+0 to 24+6 weeks.
C
Disregard criteria were cases of multiple pregnancy,
preterm amenorrhea, beginning of preterm delivery, fetus Figs 3A to C: Cervical incompetence in cerclage

with development anomalies, or ultrasound markers of

chromosomal anomalies. order to disclose urogenital infection (microscopy of
Estimation of condition of uterine cervix was made by discharge of vagina and cervical canal, cervical smear,
certified specialists with usage of ultrasonic device Voluson bacteriological inspection of discharge of cervical canal,
E8 with transvaginal multifrequency detector based on molecular-biological inspection via multiplex real-time
common practice. There were estimations of closed part polymerase chain reaction for typing of bacterium
of cervical canal and condition of internal mouth (Fig. 2). (“Femoflor” test).
Pregnancy term is defined based on last menstruation Decision of ways of CI correction was made in the
and confirmed via ultrasonic inspection or only on ultra- light of received data. Cervical incompetence correction
sound results if ultrasound gestation period inspection with usage of silicone cerclage obstetrics pessary by “Dr
results are distinguished from menstrual term for more Arabin” was used with gravidas, whose anamnesis was
than 5 days. not a burden. The same case in high-risk groups was
All gravidas’ anamnesis were scrutinized and solved by surgical correction via McDonald suture using
complex clinic–laboratorial inspection was made in nonabsorbable synthetic filament (Fig. 3).
Donald School Journal of Ultrasound in Obstetrics and Gynecology, July-September 2017;11(3):203-209 205
Larisa D Belotserkovtseva et al

All clinical records were retrospectively scrutinized by has no significant differences between groups. Quantity
experts in order to decide whether protocol was abided of gravidas with weight deficit is about 5% and was quiet
fully or fractionary. Sixty-five cases from 370 protocols similar in comparison groups.
were executed not in full measure. Comparison was made None of the significant differences on parity between
between gravidas whose protocols were executed both comparison groups were disclosed. Special attention
entirely and fractionary. Birth in <37 weeks was claimed should be paid to high ratio of preterm delivery in anam-
as basic outcome. Secondary outcome was termination nesis, habitual miscarriage, and frequency of immature
of pregnancy in term less than 22+0 weeks, unprompted birth in anamnesis of gravidas with CI. Disclosed risk
delivery in term less than 28+0 and 32+0 gestation weeks, factors ratify that CIs have entwinement with burden
birth in time, and also weight of fetus at the birth, quan- anamnesis.
tity of neonatal intensive care unit (NICU), and perinatal Table 2 presents pregnancy outcomes in research
death. group. Exposure of CI at the time of first screening assay
Intragroup comparisons were made with usage of raises a question about further management guidelines.
Fisher’s exact test for quantitative variables. Chi-square Experience of our center leads to the fact that CI correc-
test was used for qualitative variables. Furthermore, risk tion in risk group can result in carrying a pregnancy up
ratio and 95% CI were calculated. to full term for more than two-thirds of gravidas. It can
In order to compare duration of treatment in NICU, be seen that delivery in term 22+0 to 27+6 weeks happened
median line and interquartile interval were calculated in in every 20th case, whether protocol abidance performed
comparison groups; p < 0.05 was considered as statisti- entirely or fractionary. Unprompted pregnancy termina-
cally significant. All mathematical calculations were done tion in term <22+0 weeks happened to 7.8% patients with
via MS Excel. CI. Results of group with fully performed protocol turned
out to be the best for all gravidas involved in research.
RESULTS AND DISCUSSION
However, such differences were disclosed in com-
During the time of research, 370 gravidas with CI were parison between groups with fully or fractionary
disclosed. Demographical and clinical characteristics of executed protocol. In groups with full protocol abid-
gravidas who were involved in research are presented ance, more than dual-fold decrease of risk ratio of extra
in Table 1. Average age of patients is about 30 years and early preterm delivery was noted (4.3 vs 12.3%; RR 0.47;

Table 1: Demographic and clinical characteristics involved in research gravidas

Full protocol Fractionary protocol   Possibility of
abidance (n = 305) abidance (n = 65) differences (р)
Age (years) 28 (±4.9) 27 (±4.6) >0.05
Smoking 14 (4.6) 4 (6.1) >0.05
BMI (kg/m2) 22.3 (±4.9) 22.3 (±3.5) >0.05
BMI < 18 15 (4.9) 3 (4.6) >0.05
Nonparous 174 (57.0) 36 (55.3) >0.05
Preterm delivery in anamnesis 126 (41.3) 27 (41.5) >0.05
Two or more unprompted abortion after 14 weeks 62 (20.3) 14 (21.5) >0.05
Curettage of uterine cavity in anamnesis 203 (66.5) 40 (61.5) >0.05
Cervical canal length at diagnosis time 19.1 (±5.8) 16.9 (±5.8) >0.05
Pregnancy term at diagnosis 20.0 (±1.1) 21.3 (±1.0) >0.05
Data presented as average (mean-square deviation) or as n (%)

Table 2: Influence of protocol abidance on delivery time

Full protocol abidance Fractionary protocol
Delivery time Total (n = 370) (n = 305) abidance (n = 65) RR (95% CI)
<22+0 weeks 29 (7.8) 20 (6.6) 9 (13.8) 0.47 (0.23–0.99)*
22+0–27+6 weeks 21 (5.7) 13 (4.3) 8 (12.3) 0.35 (0.15–0.80)*
28+0–36+6 weeks 51 (13.8) 36 (11.8) 15 (23.1) 0.81 (0.30–0.88)*
+0
>37 weeks 269 (72.7) 236 (77.4) 33 (50.8) 1.52 (1.19–1.95)*
Data presented as n (%); RR and 95% CI calculated between groups with full or fractionary protocol abidance, *differences are
statistically authentic

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Cervical Incompetence: Modern Clinical Protocols and Real Practice

Table 3: Fetus mass in cases of full or fractionary Table 4: Frequency of mistake occurrence during management
protocol abidance of gravidas with CI according to delivery time
Fractionary Delivery time
Full protocol protocol <22+0 22+0–27+6 28+0–36+6 >37+0
  Fetus weight abidance abidance weeks weeks weeks weeks
(gm) (n = 305) (n = 65) RR (95% CI) Exposed mistakes (n = 9) (n = 8) (n = 15) (n = 33)
<500 20 (6.6) 9 (13.8) 0.47 (0.23–0.99)* Risk group was 5 7 7 11
  500–999 10 (3.3) 7 (10.8) 0.30 (0.12–0.77)* not disclosed from
  1,000–1,500 11 (3.0) 5 (7.6) 0.47 (0.17–1.3) anamnesis
  1,500–1,999 9 (3.0) 6 (9.2) 0.32 (0.12–0.87)* Wrong choice of 3 5 3 9
>2,000 255 (83.6) 38 (58.5) 1.43 (1.16–1.77)* correction method
Data are presented as n (%), *differences are statistically authentic Irrational treatment 3 4 4 8
of genital system
infections
95% CI 0.23–0.99). Quantity of unprompted pregnancy Incorrect supersonic 2 2 3 5
termination in term <22+0 weeks also decreased more inspection
than dual-fold (6.6 vs 13.8%; RR 0.47; 95% CI 0.23–0.99).
Such tendency remained in every researched interval.
Statistically authentic data from term 28+0 to 36+6 between
two groups with fully or fractionary protocol abidance
were achieved (11.8 vs 23.1%; RR 0.81; 95% CI 0.30–0.88).
In case of fractionary protocol abidance, quantity of
delivery in term >37 weeks decreases by one-third (77.4
vs 50.8%; RR 1.52; CI 1.19–1.95).
Weight of newborn is one of the key factors that influ-
ences perinatal morbidity and death rate. As presented
in Table 3, newborn weight <1,000, 1,500, 2,000 gm much
more frequently appears in cases of fractionary protocol
abidance. Newborns’ weight has distinct correlation with
gestation period and confirms importance of scrutinous
performance of clinical protocol. Fig. 4: Cervical incompetence
Process of improving situation was gradual: Exposure
and grading of mistakes, staff training, supervise on
Worst conceivable accident is combination of several
protocol abidance, and detailed case study of every extra
mistakes in one patient’s case. It mostly happened with
early preterm delivery accident. Frequency of different
gravidas, who had extra early preterm delivery according
mistakes is presented in Table 4.
to our data. It shows the following clinical case.
Most frequent mistake was not including patient in
Gravida M, 36 years old, was admitted to hospital
risk group according to anamnesis. This mistake led to
on September 24, 2012 in pregnancy term of 19+2 weeks,
absence of both vaginal progesterone prescription and
with first-time exposure of cervical canal’s shortening
monitoring cervical canal length from 14 to 18 weeks. It down to 24 mm. Anamnesis contained information
results either in unprompted pregnancy termination or about five artificial abortions, sixth pregnancy’s ending
late treatment in worse conditions (Fig. 4). with spontaneous abortion on 19th week in the setting
Next on frequency rate mistake is wrong choice of of fetal bladder prolapse and premature amenorrhea.
ways of CI correction: Nonuse of cerclage for gravidas Proving ultrasonic inspection exposed shortening of
with burden anamnesis and nonuse of cervical pessary cervical canal down to 11.3 mm and its U-shape widen-
for gravidas with exposed shortening of cervical canal. ing (Fig. 6).
Another serious problem is prevalence of genital system Correction via cervical pessary and vaginal proges-
infections. Long and ineffective treatment genital tract terone took place. Premature amenorrhea happened on
infection of gravidas, whom needed surgical correction of 22+2 term. On 22+4 week term dead fetus (560 gm) delivery
cervical incompetence led to protract necessary treatment. happened.
Mistakes within ultrasound inspection also can be Analysis of this case shows combination of typical
mentioned as reason of failure, while other mistakes are mistakes, such as lack of attention for burden anamne-
connected with wrong sizing of cervical canal length and sis, wrong choice of CI correction method, and incorrect
wrong interpretation of its shape (Fig. 5). ultrasound inspection.
Donald School Journal of Ultrasound in Obstetrics and Gynecology, July-September 2017;11(3):203-209 207
Larisa D Belotserkovtseva et al

A B
Figs 5A and B: Critical cervical incompetence

A B

C
Figs 6A to C: Umbilical cord prolapse of fetal bladder (gestation term 22+1)

In 2014, same patient from early term of next preg- That reduction is not clinically significant, because it
nancy was prescribed vaginal progesterone, and on 15+5 is only 2%. But this reduction happened in the setting of
term cervical cerclage was made. It resulted in conserva- absence of managing mistakes in most difficult clinical
tive delivery on 39+5 term and fetus weight 4010 gm and group, when fetus outlook is hard to predict.
8 to 9 Apgar score.
Our activity about reducing mistakes’ quantity in SUMMARY
gravidas with CI treatment resulted in decrease of mis- Both usage of effective medication or new clinical protocol
takes’ occurrence in 2014, compared with previous years. development and scrutinous abidance of conventional
Table 5 contains comparative data from 2012 to 2014. protocols, mistakes’ examination, and staff training can
Attained results show reduction of quantity of extra early be claimed as reserve for decreased quantity of extra
preterm delivery. early preterm birth.

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Cervical Incompetence: Modern Clinical Protocols and Real Practice

Table 5: Comparison of delivery date and quantity of exposed departures from clinical protocol in 2012 and 2014
<22+0 weeks 22+0–27+6 weeks 28+0–36+6 weeks >37 weeks
Mistakes Mistakes Mistakes Mistakes
Cases n (%) n (%) Cases n (%) n (%) Cases n (%) n (%) Cases n (%) n (%)
2012 (n = 87) 8 (9.2) 7 (87) 5 (5.7) 5 (100) 13 (14.9) 9 (69.2) 61 (70.1) 10 (16.3)
2014 (n = 107) 5 (4.7) 1 (20) 4 (3.7) 0 (0) 14 (13.1) 3 (21.4) 84 (78.5) 3 (3.6)
Percentage of number of cases calculated from 1 year, % of mistakes calculated from quantity of cases in group

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