Transvaginal Ultrasonography in the Prediction of Preterm Birth After Treatment for Cervical Intraepithelial Neoplasia

Cervical assessment certification and its impact on performance quality in the context of universal cervical screening

OBJECTIVE

To assess the impact of the introduction of universal transvaginal cervical screening and certification on the quality of cervical length ultrasound images.

METHODS

The present study included a retrospective cohort of singleton pregnancies that underwent transvaginal cervical length measurement at the anatomical scan (180/7 and 236/7 weeks) before (period A, 2015-2017) and after (period B, 2017-2019) the introduction of universal transvaginal cervical length screening. Independent observers blindly evaluated the images obtained for cervical length using a qualitative scoring method based on five criteria, according to the Fetal Medicine Foundation.

RESULTS

In all, 6013 patients met the inclusion criteria, 3333 in period A and 2680 in period B. Maternal characteristics and risk factors for preterm birth were similar between the two periods. The acceptance of transvaginal cervical length measurement in period B was 95.5% in the overall cohort and 100% in the subgroup of high-risk patients. The quality score was significantly higher in period B than in period A. Among the image quality criteria, the anterior/posterior ratio, the correct magnification of the images, and the calipers' placement contributed significantly to the improved quality score in period B. Most of the sonographers performed better in period B, irrespective of the years of experience, but certificate holders obtained higher scores than non-certified sonographers, particularly those in mid-career. The identification of short cervix was significantly higher in period B than in period A.

CONCLUSION

The implementation of universal transvaginal cervical length screening and the certification process are associated with improved quality of cervical length images, even among expert sonographers and in the presence of anatomical pitfalls.

Hyposecretion of cervical MUC5B is related to preterm birth in pregnant women after cervical excisional surgery

PROBLEM

Excisional surgery for cervical intraepithelial neoplasia is a risk factor for preterm birth in subsequent pregnancies. However, the underlying mechanisms of this association remain unclear. We previously showed that cervical MUC5B, a mucin protein, may be a barrier to ascending pathogens during pregnancy. We thus hypothesized that hyposecretion of cervical MUC5B is associated with preterm birth after cervical excisional surgery.

METHOD OF STUDY

This prospective nested case-control study (Study 1) included pregnant women who had previously undergone cervical excisional surgery across 11 hospitals. We used proteomics to compare cervicovaginal fluid at 18-22 weeks of gestation between the preterm and term birth groups. In another case-control analysis (Study 2), we compared MUC5B expression in nonpregnant uterine tissues between 15 women with a history of cervical excisional surgery and 26 women without a history of cervical surgery.

RESULTS

The abundance of MUC5B in cervicovaginal fluid was significantly decreased in the preterm birth group (fold change = 0.41, p = .035). Among the 480 quantified proteins, MUC5B had the second highest positive correlation with gestational age at delivery in the combined preterm and term groups. The cervicovaginal microbiome composition was not significantly different between the two groups. Cervical length was not correlated with gestational age at delivery (r = 0.18, p = .079). Histologically, the MUC5B-positive area in the nonpregnant cervix was significantly decreased in women with a history of cervical excisional surgery (0.85-fold, p = .048). The distribution of MUC5B-positive areas in the cervical tissues of 26 women without a history of cervical excisional surgery differed across individuals.

CONCLUSIONS

This study suggests that the primary mechanism by which cervical excisional surgery causes preterm birth is the hyposecretion of MUC5B due to loss of the cervical glands.

Pregnancy Outcome Following Treatment of Premalignant Lesion of the Cervix in Southeast Nigeria; A Retrospective Case-Control Study

BACKGROUND

Treatment of cervical pre-cancers involves ablative and excisional therapies, and these have the potential to affect future pregnancy outcomes of women. Understanding the impact of the various treatment modalities on the outcome of pregnancies can motivate the development of interventions to improve pregnancy outcomes in women who had cervical pre-cancer treatment.

AIM

We aimed to the effect of cervical pre-cancer treatment on second-trimester miscarriages and preterm births.

MATERIALS AND METHODS

Matched case-control study in which 373 women who had a pregnancy after cervical pre-cancer treatment were matched with 373 controls. McNemar Chi-square was used to compare the prevalence of second-trimester miscarriage and preterm birth between the study group and the matched controls. Conditional logistic regression analysis was done to determine the risk factors for second-trimester miscarriage and preterm birth.

RESULTS

Second-trimester miscarriages and preterm births were higher in women who had cervical pre-cancer treatment (AOR: 2.05, 95% CI: 1.174 - 3.693, p: 0.01) and (AOR: 2.74, 95% CI: 1.591 - 4.902, p: 0.0001) respectively. In addition, large loop excision of the transformation zone (LLETZ) of the cervix increased the odds of second-trimester miscarriage (AOR: 1.22, 95% CI: 1.034 - 1.441, p: 0.019) and preterm birth (AOR: 2.98, 95% CI: 1.793 - 3.965, p: 0.001). Cryotherapy and thermocoagulation were not associated with increased miscarriage and preterm birth. Treatment to pregnancy interval of ≥ 12 months decreased the odds of second-trimester miscarriage (AOR: 0.605, 95% CI: 0.502 - 0.808, p: 0.031) and preterm birth (AOR: 0.484, 95% CI: 0.317 - 0.738, p: 0.001).

CONCLUSION

There is an increased odds of second-trimester miscarriage and preterm birth in women treated with LLETZ. A treatment-to-pregnancy interval of ≥ 12 months reduces this odd. Ablative therapies do not increase the odds of miscarriages and preterm births. This information could guide decisions on the choice of method of treatment for cervical pre-cancer in women of childbearing age.

Association between loop electrosurgical excision procedure and adverse pregnancy outcomes: a meta-analysis

OBJECTIVE

To assess the association between loop electrosurgical excision procedure (LEEP) and adverse pregnancy outcomes.

METHODS

The databases including PubMed, Embase, Cochrane Library and Web of science were searched from inception to December 27th, 2020. Odds ratio (OR) and 95% confidence interval (CI) were utilized to calculate the association between LEEP and adverse pregnancy outcomes. Heterogeneity test was performed for each outcome effect amount. If I² ≥ 50%, the random-effects model was conducted, otherwise, fixed-effects model was performed. Sensitivity analysis was performed on all outcomes. Publication bias was performed by Begg's test.

RESULTS

A total of 30 studies containing 2,475,421 patients were included in this study. The results showed that patients who received the LEEP before pregnancy had a higher risk of preterm delivery (OR: 2.100, 95%CI: 1.762-2.503, p  <  .001), premature rupture of fetal membranes (OR: 1.989, 95%CI: 1.630-2.428, p  <  .001) and low birth weight infants (OR: 1.939, 95%CI: 1.617-2.324, p  <  .001) in comparison with controls. Subgroup analysis further found that prenatal LEEP treatment was associated with the risk of preterm birth subsequently.

CONCLUSION

LEEP treatment before pregnancy may increase the risk of preterm delivery, premature rupture of fetal membranes and low birth weight infants. It is necessary to do a regular prenatal examination and early intervention in a timely manner to reduce the risk of adverse pregnancy outcomes after LEEP.

Midtrimester cervical elastography in pregnant women with a history of loop electrosurgical excision procedure (LEEP)

We aimed to compare cervical elastographic parameters based on a previous loop electrosurgical excision procedure (LEEP) and to determine whether they can predict preterm delivery in pregnant women with a history of LEEP. This multicenter prospective case-control study included 71 singleton pregnant women at 14-24 weeks of gestation with a history of LEEP and 1:2 gestational age-matched controls. We performed cervical elastography using E-cervix and compared maternal characteristics, delivery outcomes, cervical length (CL), and elastographic parameters between the two groups. The median mid-trimester CL was significantly shorter in the LEEP group. Most elastographic parameters, including internal os (IOS), external os (EOS), elasticity contrast index (ECI), and hardness ratio (HR), were significantly different in the two groups. In the LEEP group, the sPTD group compared to the term delivery (TD) group showed a higher rate of previous sPTD (50% vs. 1.7%, p < 0.001), higher IOS and ECI (IOS: 0.28 [0.12-0.37] vs. 0.19 [0.10-0.37], p = 0.029; ECI: 3.89 [1.79-4.86] vs. 2.73 [1.48-5.43], p = 0.019), and lower HR (59.97 [43.88-92.43] vs. 79.06 [36.87-95.40], p = 0.028), but there was no significant difference in CL (2.92 [2.16-3.76] vs. 3.13 [1.50-3.16], p = 0.247). In conclusion, we demonstrated that a history of LEEP was associated with a change in cervical strain measured in mid-trimester as well as with CL shortening. We also showed that cervical elastography can be useful in predicting sPTD in pregnant women with previous LEEP.

Guideline No. 398: Progesterone for Prevention of Spontaneous Preterm Birth

OBJECTIVES

To assess the benefits and risks of progesterone therapy for women at increased risk of spontaneous preterm birth (SPB) and to make recommendations for the use of progesterone to reduce the risk of SPB and improve postnatal outcomes.

OPTIONS

To administer or withhold progesterone therapy for women deemed to be at high risk of SPB.

OUTCOMES

Preterm birth, neonatal morbidity and mortality, and postnatal outcomes including neurodevelopmental outcomes.

INTENDED USERS

Maternity care providers, including midwives, family physicians, and obstetricians.

TARGET POPULATION

Pregnant women at increased risk of SPB.

EVIDENCE

Medline, PubMed, EMBASE, and the Cochrane Library were searched from inception to October 2018 for medical subject heading (MeSH) terms and keywords related to pregnancy, preterm birth, previous preterm birth, short cervix, uterine anomalies, cervical conization, neonatal morbidity and mortality, and postnatal outcomes. This document represents an abstraction of the evidence rather than a methodological review.

VALIDATION METHODS

This guideline was reviewed by the Maternal-Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada (SOGC) and approved by the SOGC Board of Directors.

BENEFITS, HARMS, AND/OR COSTS

Therapy with progesterone significantly reduces the risk of SPB in a subpopulation of women at increased risk. Although this therapy entails a cost to the woman in addition to the discomfort associated with its use, no other adverse effects to the mother or the baby have been identified.

SUMMARY STATEMENTS (GRADE RATINGS IN PARENTHESES)

RECOMMENDATIONS (GRADE RATINGS IN PARENTHESES).

Guideline No. 401: Sonographic Cervical Length in Singleton Pregnancies: Techniques and Clinical Applications

OBJECTIVES

• To assess the association between sonography-derived cervical length measurement and preterm birth. • To describe the various techniques to measure cervical length using sonography. • To review the natural history of the short cervix. • To review the clinical uses, predictive ability, and utility of sonography-measured short cervix.

OUTCOMES

Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions.

INTENDED USERS

Clinicians involved in the obstetrical management or cervical imaging of patients at increased risk of a short cervix.

TARGET POPULATION

Women at increased risk of a short cervix or at risk of preterm birth.

EVIDENCE

Literature published up to June 2019 was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, cervical insufficiency, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence and this guideline were reviewed by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made and graded according to the rankings of the Canadian Task Force on Preventive Health Care (Online Appendix Table A1).

BENEFITS, HARMS, COSTS

Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the sonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth. SUMMARY STATEMENTS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES): RECOMMENDATIONS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES).

Morbidity after local excision of the transformation zone for cervical intra-epithelial neoplasia and early cervical cancer

The awareness that cervical intra-epithelial neoplasia (CIN) treatment increases the risk of preterm birth has led to major changes in clinical practice. Women with CIN have a higher baseline risk of prematurity but local treatment further increases this risk. The risk further increases with increasing cone length and multiplies for repeat excisions; it is unclear whether small cones confer any additional risk to CIN alone. There is no evidence to suggest that fertility is affected by local treatment, although this increases the risk of mid-trimester loss. Caution should prevail when deciding to treat women with CIN of reproductive age. If treatment is offered, this should be conducted effectively to optimise the clearance of disease and minimise the risk of recurrence. Colposcopists should alert women undergoing treatment that this may increase the risk of preterm birth and that they may be offered interventions when pregnant. The cone length should be clearly documented and used as a risk stratifier.

Cervical intraepithelial neoplasia and the risk of spontaneous preterm birth: A Dutch population-based cohort study with 45,259 pregnancy outcomes

BACKGROUND

Excisional procedures of cervical intraepithelial neoplasia (CIN) may increase the risk of preterm birth. It is unknown whether this increased risk is due to the excision procedure itself, to the underlying CIN, or to secondary risk factors that are associated with both preterm birth and CIN. The aim of this study is to assess the risk of spontaneous preterm birth in women with treated and untreated CIN and examine possible associations by making a distinction between the excised volume of cervical tissue and having cervical disease.

METHODS AND FINDINGS

This Dutch population-based observational cohort study identified women aged 29 to 41 years with CIN between 2005 and 2015 from the Dutch pathology registry (PALGA) and frequency matched them with a control group without any cervical abnormality based on age at and year of pathology outcome (i.e., CIN or normal cytology) and urbanization (<100,000 inhabitants or ≥100,000 inhabitants). All their 45,259 subsequent singleton pregnancies with a gestational age ≥16 weeks between 2010 and 2017 were identified from the Dutch perinatal database (Perined). Nineteen potential confounders for preterm birth were identified. Adjusted odds ratios (ORs) were calculated for preterm birth comparing the 3 different groups of women: (1) women without CIN diagnosis; (2) women with untreated CIN; and (3) women with treated CIN prior to each childbirth. In total, 29,907, 5,940, and 9,412 pregnancies were included in the control, untreated CIN, and treated CIN group, respectively. The control group showed a 4.8% (1,002/20,969) proportion of spontaneous preterm birth, which increased to 6.9% (271/3,940) in the untreated CIN group, 9.5% (600/6,315) in the treated CIN group, and 15.6% (50/321) in the group with multiple treatments. Women with untreated CIN had a 1.38 times greater odds of preterm birth compared to women without CIN (95% confidence interval (CI) 1.19 to 1.60; P < 0.001). For women with treated CIN, these odds 2.07 times increased compared to the control group (95% CI 1.85 to 2.33; P < 0.001). Treated women had a 1.51 times increased odds of preterm birth compared to women with untreated CIN (95% CI 1.29 to 1.76; P < 0.001). Independent from cervical disease, a volume excised from the cervix of 0.5 to 0.9 cc increased the odds of preterm birth 2.20 times (37/379 versus 1,002/20,969; 95% CI 1.52 to 3.20; P < 0.001). These odds further increased 3.13 times and 5.93 times for women with an excised volume of 4 to 8.9 cc (90/724 versus 1,002/20,969; 95% CI 2.44 to 4.01; P < 0.001) and ≥9 cc (30/139 versus 1,002/20,969; 95% CI 3.86 to 9.13; P < 0.001), respectively. Limitations of the study include the retrospective nature, lack of sufficient information to calculate odds of preterm birth <24 weeks, and that the excised volume could only be calculated for a select group of women.

CONCLUSIONS

In this study, we observed a strong correlation between preterm birth and a volume of ≥0.5 cc excised cervical tissue, regardless of the severity of CIN. Caution should be taken when performing excisional treatment in women of reproductive age as well as prudence in case of multiple biopsies. Fertile women with a history of performing multiple biopsies or excisional treatment for CIN may benefit from close surveillance during pregnancy.

Changes in gene expression of cervical collagens, metalloproteinases, and tissue inhibitors of metalloproteinases after partial cervical excision-induced preterm labor in mice

We investigated changes in gene expression of cervical collagens, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs) during pre-gestational uterine cervical excision and/or inflammation-induced preterm labor in mice. Forty sexually mature female mice were uniformly divided into four groups: sham, cervical excision, lipopolysaccharide (LPS) injection, and cervical excision plus LPS injection. Partial cervical tissue excision was performed at five weeks of age before mating. LPS was injected into the lower right uterine horn near the cervix on gestational day 16. Mice were sacrificed immediately postpartum. Uterine cervices were collected and subjected to quantitative real-time PCR. Col4α1 and Col5α1 expression increased significantly in the cervical excision plus LPS injection group compared to the sham group (p < 0.01 and p = 0.024, respectively). MMP-14 expression levels increased in the cervical excision plus LPS injection group compared to the sham group (p < 0.01). TIMP-1 expression was not significantly decreased in this group. Increased expression levels of Col4α1, Col5α1, and MMP-14 were associated with cervical excision plus inflammation-induced preterm labor. Thus, pre-gestational cervical remodeling through specific collagen metabolism and MMP activation may involve the pathogenesis of spontaneous preterm labor.

Relationship between cervical excisional treatment for cervical intraepithelial neoplasia and obstetrical outcome

INTRODUCTION

The aim of our systematic review was the assessment of effects of excisional treatments for the management of cervical intraepithelial neoplasia (CIN) on preterm delivery (PD), lower birth weight (LBW), preterm premature rupture of membrane (PPROM) and obstetrical outcomes.

EVIDENCE ACQUISITION

A structured search was carried out in PubMed-Medline, Embase, and Cochrane Controlled Trials Register databases through November 30, 2019. The search included a combination of the following terms: "loop electrosurgical excision procedure (LEEP)," "large loop excision of transformation zone (LLETZ)," "cold-knife conization (CKC)," "laser cervical conization (CLC)," "preterm delivery" and "neonatal outcome."

EVIDENCE SYNTHESIS

Thirty-two of 561 publications considered were included: 28 retrospective series, 2 prospective studies and 2 multicenter trials. Globally in several studies there was a significant increase in PD, measured by the relative risk, in the women underwent a surgical procedure for the CIN. In their majority, the studies were retrospective and therefore a high risk of bias.

CONCLUSIONS

This systematic review shows that the surgical treatment of the CIN was associated with an increased risk of PD, LBW and pPROM before 37 pregnancy weeks compared to untreated women, especially in a CKC and LLETZ procedure. Moreover, the increase of the of PD was associated with cone size, cervical length, repeated treatment and a short conization-to-pregnancy interval.

Pregnancy outcomes following elective abdominal cerclage following cervical excision surgery for neoplastic disease

BACKGROUND

Local excisional treatment of neoplastic disease of the cervix in the form of loop excision (LLETZ) and conisation has been associated with adverse pregnancy outcomes including prelabour premature rupture of membranes (PPROM) and spontaneous preterm birth (SPTB). Insertion of a cervical cerclage is indicated for women with a short cervix <25 mm between 16 and 24 weeks gestation who also have a history of either PPROM or a history of cervical excisional treatment. The optimum timing of the cerclage and surgical technique used are both open to debate. This retrospective review of cases was performed to examine the outcomes of elective pre pregnancy placement of abdominal cervical cerclage in women who have undergone cervical excision surgery for neoplastic disease.

METHODS

This was a retrospective review of case notes. Over a 10 year period 20 women who had previous cervical excision surgery had pre-pregnancy abdominal cerclage placed became pregnant with 26 pregnancies. One woman had a cone biopsy, 9 had a single LLETZ procedure, 8 had 2 LLETZ procedures and 2 women had 3 LLETZ procedures prior to the cerclage.

RESULTS

21 pregnancies were achieved spontaneously, 1 by intrauterine insemination (IUI) and 4 were conceived by in-vitro fertilisation (IVF). Overall, 22 of 26 (84.6 %) pregnancies were delivered at term. There was a single 7 week miscarriage and 3 premature deliveries (12 %) including 1 preterm birth at 29 + 4 weeks gestation after an antepartum haemorrhage (APH) and 2 late preterm births at 36 + 3 (following APH) and 36 + 4 weeks gestation following preterm labour. All 25 women were delivered by Caesarean section and all 25 babies survived.

CONCLUSION

There results of prophylactic minimally invasive insertion of a transabdominal cerclage in women with LLETZ treatments or cone biopsy prior to pregnancy demonstrated 84.6 % of pregnancies resulted in a live birth. The premature delivery rate was 12 %.

Management of pregnancy after fertility-sparing surgery for cervical cancer

Cervical cancer is increasingly diagnosed in women who have not yet completed their reproductive plans. For women with early-stage disease (FIGO stage IA1-IB1), fertility-sparing procedures, such as conization, trachelectomy or radical trachelectomy, represent the treatments of choice. However, women who undergo repeated conization or trachelectomy represent a challenge for obstetricians because they are at increased risk of infertility, mid-trimester miscarriage, preterm premature rupture of membranes and preterm delivery. So far, the evidence-based guidance on the management of these pregnancies is limited. This article reviews the literature discussing pregnancy management in women after fertility-sparing surgery for early cervical cancer. Although the evidence is limited, certain measures are desirable, including screening and treatment of asymptomatic bacteriuria, screening for cervical incompetence and progressive cervical shortening by transvaginal ultrasonography, and fetal fibronectin testing. Vaginal progesterone supplementation should be primary prevention for all women after trachelectomy. Women with a history of preterm delivery or late miscarriage may benefit from cervical cerclage. Elective delivery by cesarean section in the early-term period is desirable.

Very short cervix in low-risk asymptomatic singleton pregnancies: Outcome according to treatment and cervical length at diagnosis

INTRODUCTION

The aim of this study was to explore the outcome of low-risk singleton pregnancies with very short cervical length (CL ≤15 mm) according to method of treatment and CL at diagnosis.

MATERIAL AND METHODS

Retrospective study on singleton pregnancies devoid of risk factors for spontaneous preterm delivery identified in the course of universal screening programs by vaginal sonography at 20-24 weeks of gestation to have very short CL ≤ 15 mm.

RESULTS

The study group consisted of 233 pregnancies with CL ≤ 15 mm of which 88 had cervical cerclage inserted and the remaining 145 were treated with vaginal progesterone. Mean CL at diagnosis was significantly shorter in the cerclage group (5 mm) compared with the progesterone group (12 mm). Regardless of treatment there was no difference in the rate of spontaneous preterm delivery at <32 weeks of gestation in women with CL ≥ 9 mm at screening (11% and 12% in the cerclage and progesterone groups, respectively). In contrast, in the subgroup with CL ≤ 8 mm cervical cerclage resulted in significantly lower rates of spontaneous preterm delivery at <32 weeks of gestation compared with progesterone treatment (20% and 45%, respectively, P = .009) and the median gestational age at birth was significantly greater (37 weeks vs 36 weeks, respectively, P = .013).

CONCLUSIONS

The majority of asymptomatic singleton pregnancies with short CL will remain undelivered until 32 weeks of gestation whether treated with progesterone or cerclage. Women with extreme cervical shortening appear to benefit more from cervical cerclage.

Ablative Therapies for Cervical Intraepithelial Neoplasia in Low-Resource Settings: Findings and Key Questions

Barriers to access for cervical precancer care in low-resource settings go beyond cost. Gas-based cryotherapy has emerged as the standard treatment in these areas, but there are barriers to this technology that have necessitated the development and implementation of affordable and portable alternatives. This review identifies knowledge gaps with regard to technologies primarily used in low-resource settings, including standard cryotherapy, nongas-based cryotherapy, and thermoablation. These gaps are addressed using evidence-based guidelines, patient and provider acceptability, long-term obstetric outcomes, and treatment of women with HIV infection. This review highlights the need for prospective studies that compare ablative methods, especially given the increasing use of thermoablation.

Change in cervical length and spontaneous preterm birth in nulliparous women with a history of loop electrosurgical excision procedure

BACKGROUND

Prior studies have shown an association between history of loop electrode procedures (LEEP) and spontaneous preterm delivery (SPTD) independent of mid-trimester cervical length. These studies suggest that there may be other factors beyond an individual cervical length, which contribute to identifying at-risk pregnancies.

OBJECTIVE

The objective of this study is to determine the association between change in cervical length and SPTD in women with a history of LEEP.

STUDY DESIGN

This is a retrospective cohort study of singleton nulliparous women with a history of LEEP who received serial cervical length measurements at a single institution between 2012 and 2016. Women with serial cervical lengths and available outcome data were included. The cervical length at different gestational ages and the rate of change in length were compared with the risk for SPTD <37 weeks using Student's t-test.

RESULTS

One-hundred-thirty subjects met the inclusion criteria for the study. The mean cervical length (35.3 versus 39.8 mm, p = .042 at 16 weeks; 32.2 versus 37.8 mm, p < .01 at 20 weeks; 29.9 versus 35.6 mm, p = .027 at 24 weeks; 21.6 versus 33.4 mm, p < .01 at 28 weeks) was significantly different between women who had an SPTD <37 weeks compared to women who did not. The average rate of change in transvaginal cervical length between 16 to 28 weeks was significantly different between women who had an SPTD <37 weeks compared to women who did not (-1.4 versus 0.4 mm/week, p < .01).

CONCLUSION

Women with a history of LEEP who had an SPTD <37 weeks had a shorter cervical length at 16, 20, 24, and 28 weeks' gestation and a higher rate of change in cervical length between 16 and 28 weeks than women without a history of SPTD. Our findings support the concept of the preterm birth syndrome as an evolving biophysical process rather than a distinct event, suggesting improved prediction in the setting of prior history of a LEEP with serial imaging.

Predictors of preterm birth

Cervical length (CL) measured by transvaginal ultrasound examination (TVUE) best identifies the risk for preterm birth (PTB). It identifies women at risk who can benefit from corticosteroids or in utero transfer. Early screening improves effectiveness of tocolysis. It reduces iatrogenicity and cost. In preterm premature rupture of membranes (PPROM), CL is devoid of infectious risk and predicts duration of the latency phase but not the risk of perinatal sepsis. Asymptomatic women at risk should be screened at a 2-week interval starting from 16 to 18 weeks, up to 24 weeks. CLs <10th centile are at risk of PTB, especially with decrease in CL after 16 weeks. Repeat ultrasound improves predictive values. Stable CL calls for term delivery. Funneling does not improve predictivity of CL. In twin pregnancies, CL reduces unnecessary interventions. In symptomatic women, fetal fibronectin performs less than CL. Its combination with inconclusive CL has not emerged productive through randomized controlled trials (RCTs), and studies with homogeneous management for preterm labor (PTL) suggest that up to 15% of unjustified hospitalizations and treatment could be avoided.

Obstetric outcomes after conservative treatment for cervical intraepithelial lesions and early invasive disease

BACKGROUND

The mean age of women undergoing local treatment for pre-invasive cervical disease (cervical intra-epithelial neoplasia; CIN) or early cervical cancer (stage IA1) is around their 30s and similar to the age of women having their first child. Local cervical treatment has been correlated to adverse reproductive morbidity in a subsequent pregnancy, however, published studies and meta-analyses have reached contradictory conclusions.

OBJECTIVES

To assess the effect of local cervical treatment for CIN and early cervical cancer on obstetric outcomes (after 24 weeks of gestation) and to correlate these to the cone depth and comparison group used.

SEARCH METHODS

We searched the following databases: Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library, 2017, Issue 5), MEDLINE (up to June week 4, 2017) and Embase (up to week 26, 2017). In an attempt to identify articles missed by the search or unpublished data, we contacted experts in the field and we handsearched the references of the retrieved articles and conference proceedings.

SELECTION CRITERIA

We included all studies reporting on obstetric outcomes (more than 24 weeks of gestation) in women with or without a previous local cervical treatment for any grade of CIN or early cervical cancer (stage IA1). Treatment included both excisional and ablative methods. We excluded studies that had no untreated reference population, reported outcomes in women who had undergone treatment during pregnancy or had a high-risk treated or comparison group, or both DATA COLLECTION AND ANALYSIS: We classified studies according to the type of treatment and the obstetric endpoint. Studies were classified according to method and obstetric endpoint. Pooled risk ratios (RR) and 95% confidence intervals (CIs) were calculated using a random-effects model and inverse variance. Inter-study heterogeneity was assessed with I2 statistics. We assessed maternal outcomes that included preterm birth (PTB) (spontaneous and threatened), preterm premature rupture of the membranes (pPROM), chorioamnionitis, mode of delivery, length of labour, induction of delivery, oxytocin use, haemorrhage, analgesia, cervical cerclage and cervical stenosis. The neonatal outcomes included low birth weight (LBW), neonatal intensive care unit (NICU) admission, stillbirth, perinatal mortality and Apgar scores.

MAIN RESULTS

We included 69 studies (6,357,823 pregnancies: 65,098 pregnancies of treated and 6,292,725 pregnancies of untreated women). Many of the studies included only small numbers of women, were of heterogenous design and in their majority retrospective and therefore at high risk of bias. Many outcomes were assessed to be of low or very low quality (GRADE assessment) and therefore results should be interpreted with caution. Women who had treatment were at increased overall risk of preterm birth (PTB) (less than 37 weeks) (10.7% versus 5.4%, RR 1.75, 95% CI 1.57 to 1.96, 59 studies, 5,242,917 participants, very low quality), severe (less than 32 to 34 weeks) (3.5% versus 1.4%, RR 2.25, 95% CI 1.79 to 2.82), 24 studies, 3,793,874 participants, very low quality), and extreme prematurity (less than 28 to 30 weeks) (1.0% versus 0.3%, (RR 2.23, 95% CI 1.55 to 3.22, 8 studies, 3,910,629 participants, very low quality), as compared to women who had no treatment.The risk of overall prematurity was higher for excisional (excision versus no treatment: 11.2% versus 5.5%, RR 1.87, 95% CI 1.64 to 2.12, 53 studies, 4,599,416 participants) than ablative (ablation versus no treatment: 7.7% versus 4.6%, RR 1.35, 95% CI 1.20 to 1.52, 14 studies, 602,370 participants) treatments and the effect was higher for more radical excisional techniques (less than 37 weeks: cold knife conisation (CKC) (RR 2.70, 95% CI 2.14 to 3.40, 12 studies, 39,102 participants), laser conisation (LC) (RR 2.11, 95% CI 1.26 to 3.54, 9 studies, 1509 participants), large loop excision of the transformation zone (LLETZ) (RR 1.58, 95% CI 1.37 to 1.81, 25 studies, 1,445,104 participants). Repeat treatment multiplied the risk of overall prematurity (repeat versus no treatment: 13.2% versus 4.1%, RR 3.78, 95% CI 2.65 to 5.39, 11 studies, 1,317,284 participants, very low quality). The risk of overall prematurity increased with increasing cone depth (less than 10 mm to 12 mm versus no treatment: 7.1% versus 3.4%, RR 1.54, 95% CI 1.09 to 2.18, 8 studies, 550,929 participants, very low quality; more than 10 mm to 12 mm versus no treatment: 9.8% versus 3.4%, RR 1.93, 95% CI 1.62 to 2.31, 8 studies, 552,711 participants, low quality; more than 15 mm to 17 mm versus no treatment: 10.1 versus 3.4%, RR 2.77, 95% CI 1.95 to 3.93, 4 studies, 544,986 participants, very low quality; 20 mm or more versus no treatment: 10.2% versus 3.4%, RR 4.91, 95% CI 2.06 to 11.68, 3 studies, 543,750 participants, very low quality). The comparison group affected the magnitude of effect that was higher for external, followed by internal comparators and ultimately women with disease, but no treatment. Untreated women with disease and the pre-treatment pregnancies of the women who were treated subsequently had higher risk of overall prematurity than the general population (5.9% versus 5.6%, RR 1.24, 95% CI 1.14 to 1.34, 15 studies, 4,357,998 participants, very low quality).pPROM (6.1% versus 3.4%, RR 2.36, 95% CI 1.76 to 3.17, 21 studies, 477,011 participants, very low quality), low birth weight (7.9% versus 3.7%, RR 1.81, 95% CI 1.58 to 2.07, 30 studies, 1,348,206 participants, very low quality), NICU admission rate (12.6% versus 8.9%, RR 1.45, 95% CI 1.16 to 1.81, 8 studies, 2557 participants, low quality) and perinatal mortality (0.9% versus 0.7%, RR 1.51, 95% CI 1.13 to 2.03, 23 studies, 1,659,433 participants, low quality) were also increased after treatment.

AUTHORS' CONCLUSIONS

Women with CIN have a higher baseline risk for prematurity. Excisional and ablative treatment appears to further increases that risk. The frequency and severity of adverse sequelae increases with increasing cone depth and is higher for excision than it is for ablation. However, the results should be interpreted with caution as they were based on low or very low quality (GRADE assessment) observational studies, most of which were retrospective.

Impact of Age at Conization on Obstetrical Outcome: A Case-Control Study

Age younger than 25 year at the time of loop electrosurgical excision procedure is associated with a more frequent occurrence of preterm labor before 26 weeks of amenorrhea.

Objective

The aim of the study was to assess whether an age younger than 25 years at conization affected future pregnancy outcome as an independent factor.

Materials and Methods

A retrospective study of 115 women who underwent both loop electrosurgical excision procedure (LEEP) and subsequent pregnancy follow-up in a referral center was conducted. Two groups were considered: patients younger than 25 years at the time of LEEP (n = 42) and 25 years or older (n = 73). Analyzed data were occurrence of preterm adverse obstetrical event and, specifically, preterm labor (PL) and preterm rupture of membranes; stratification based on term of occurrence was performed: less than 37 weeks of amenorrhea (WA), less than 34 WA, and less than 26 WA.

Results

Patients characteristics were comparable in terms of excised specimen thickness and pathological analysis, as well as for tobacco intoxication during pregnancy. Although there was no difference of term at delivery or total number of preterm adverse obstetrical events, we found a significant increase of events (19% vs 4.1%) and PL (19% vs 0%) before 26 WA in the group of patients younger than 25 years. After adjusting for excised specimen thickness, the same results were found for thickness of 15 mm or less (respectively, 16.7% vs 3.3% and 16.7% vs 0%). For thickness of greater than 15 mm, only ratio of PL before 26 WA was higher in the group of patients younger than 25 years (33.3% vs 0%).

Conclusions

Age younger than 25 years at the time of LEEP seems to be is associated with a more frequent occurrence of extremely early preterm adverse obstetrical events, particularly PL.

Prevention of preterm delivery: current challenges and future prospects

Preterm birth (PTB), defined as delivery at <37 weeks of gestation, is the most important cause of neonatal morbidity and mortality. Therefore, preventing PTB is one of the main goals in obstetric care. In this review, we provide an overview of the current available literature on screening for risk factors for PTB and a summary of preventive strategies in both low-risk and high-risk women with singleton or multiple gestations. Furthermore, current challenges and future prospects on PTB are discussed. For an optimal prevention of PTB, risk stratification should be based on a combination of (maternal) risk factors, obstetric history, and screening tools. Cervical length measurements can help identify women at risk. Thereafter, preventive strategies such as progesterone, pessaries, and cerclage may help prevent PTB. Effective screening and prevention of PTB vary between the different pregnancy populations. In singleton or multiple pregnancies with a short cervix, without previous PTB, a pessary or progesterone might prevent PTB. In women with a (recurrent) PTB in the past, progesterone and a cerclage may prevent recurrence. The effect of a pessary in these high-risk women is currently being studied. A strong collaboration between doctors, patients' organizations, pharmaceutical companies, and (international) governments is needed to reduce the morbidity and mortality as a result of spontaneous PTB.

Adverse obstetric outcomes after local treatment for cervical preinvasive and early invasive disease according to cone depth: systematic review and meta-analysis

OBJECTIVE

 To assess the effect of treatment for cervical intraepithelial neoplasia (CIN) on obstetric outcomes and to correlate this with cone depth and comparison group used.

DESIGN

 Systematic review and meta-analysis.

DATA SOURCES

 CENTRAL, Medline, Embase from 1948 to April 2016 were searched for studies assessing obstetric outcomes in women with or without previous local cervical treatment.

DATA EXTRACTION AND SYNTHESIS

 Independent reviewers extracted the data and performed quality assessment using the Newcastle-Ottawa criteria. Studies were classified according to method and obstetric endpoint. Pooled risk ratios were calculated with a random effect model and inverse variance. Heterogeneity between studies was assessed with I(2) statistics.

MAIN OUTCOME MEASURES

 Obstetric outcomes comprised preterm birth (including spontaneous and threatened), premature rupture of the membranes, chorioamnionitis, mode of delivery, length of labour, induction of delivery, oxytocin use, haemorrhage, analgesia, cervical cerclage, and cervical stenosis. Neonatal outcomes comprised low birth weight, admission to neonatal intensive care, stillbirth, APGAR scores, and perinatal mortality.

RESULTS

 71 studies were included (6 338 982 participants: 65 082 treated/6 292 563 untreated). Treatment significantly increased the risk of overall (<37 weeks; 10.7% v 5.4%; relative risk 1.78, 95% confidence interval 1.60 to 1.98), severe (<32-34 weeks; 3.5% v 1.4%; 2.40, 1.92 to 2.99), and extreme (<28-30 weeks; 1.0% v 0.3%; 2.54, 1.77 to 3.63) preterm birth. Techniques removing or ablating more tissue were associated with worse outcomes. Relative risks for delivery at <37 weeks were 2.70 (2.14 to 3.40) for cold knife conisation, 2.11 (1.26 to 3.54) for laser conisation, 2.02 (1.60 to 2.55) for excision not otherwise specified, 1.56 (1.36 to 1.79) for large loop excision of the transformation zone, and 1.46 (1.27 to 1.66) for ablation not otherwise specified. Compared with no treatment, the risk of preterm birth was higher in women who had undergone more than one treatment (13.2% v 4.1%; 3.78, 2.65 to 5.39) and with increasing cone depth (≤10-12 mm; 7.1% v 3.4%; 1.54, 1.09 to 2.18; ≥10-12 mm: 9.8% v 3.4%, 1.93, 1.62 to 2.31; ≥15-17 mm: 10.1% v 3.4%; 2.77, 1.95 to 3.93; ≥20 mm: 10.2% v 3.4%; 4.91, 2.06 to 11.68). The choice of comparison group affected the magnitude of effect. This was higher for external comparators, followed by internal comparators, and ultimately women with disease who did not undergo treatment. In women with untreated CIN and in pregnancies before treatment, the risk of preterm birth was higher than the risk in the general population (5.9% v 5.6%; 1.24, 1.14 to 1.35). Spontaneous preterm birth, premature rupture of the membranes, chorioamnionitis, low birth weight, admission to neonatal intensive care, and perinatal mortality were also significantly increased after treatment. :

CONCLUSIONS

 Women with CIN have a higher baseline risk for prematurity. Excisional and ablative treatment further increases that risk. The frequency and severity of adverse sequelae increases with increasing cone depth and is higher for excision than for ablation.

Proportion of cervical excision for cervical intraepithelial neoplasia as a predictor of pregnancy outcomes

OBJECTIVE

To assess how the proportion of the cervical volume/length removed during treatment for cervical intraepithelial neoplasia (CIN) varies and whether this correlates to the pregnancy duration at delivery.

METHODS

The present prospective observational study included 142 women undergoing CIN treatment at a university hospital during 2009-2013. The pretreatment and post-treatment cervical dimensions and cone size were measured with magnetic resonance imaging, three-dimensional transvaginal ultrasonography, or two-dimensional transvaginal ultrasonography, and the correlation between pregnancy outcomes and the relative proportion of the cervix excised was assessed.

RESULTS

Pretreatment cervical volumes and cone volumes varied substantially (range 11-40 cm(3) and 0.6-8 cm(3), respectively). The proportion of the volume excised ranged from 2.2% to 39.4%. Sixteen (11%) women conceived following treatment; 12 had a live birth (seven at term, three preterm). The pregnancy duration at delivery was significantly correlated with the proportion of the cervical volume (r=-0.9; P<0.001) and length (r=-0.7; P=0.01) excised and the cone volume (r=-0.6; P=0.04).

CONCLUSION

The pretreatment cervical dimensions and the proportions of the volume/length excised vary substantially, and the latter correlates with the pregnancy duration. Assessment of the proportion excised might help to stratify women at risk who need intensive surveillance when pregnant.

The association between cervical excisional procedures, midtrimester cervical length, and preterm birth

OBJECTIVE

To determine whether a prior cervical excisional procedure (a loop electrosurgical excision procedure or cold knife cone) is associated with a short midtrimester cervical length (<3 cm) and whether having a short cervix explains the relationship between this procedure and preterm birth.

STUDY DESIGN

In this cohort study of women with a singleton pregnancy who underwent routine cervical length assessment between 18 and 24 weeks of gestation, women with a history of a prior cervical excisional procedure were compared with those without such a history. Bivariable and multivariable analyses were performed to identify whether a prior cervical excisional procedure remained an independent risk factor for preterm birth after controlling for cervical length.

RESULTS

Of the 6669 women who met inclusion criteria, 460 (6.9%) had a prior cervical excisional procedure. Mean cervical length was shorter (4.2 ± 0.9 cm vs 4.5 ± 0.9 cm, P < .001) and the proportion of women with a short cervix was higher (6.5% vs 1.5%, P < .001) in women with a prior cervical excisional procedure. In multivariable regression, both a short cervix (adjusted odds ratio, 6.19; 95% confidence interval, 3.85-9.95) and a prior cervical excisional procedure (adjusted odds ratio, 1.53; 95% confidence interval, 1.04-2.25) were significantly associated with preterm birth.

CONCLUSION

Women with a prior cervical excisional procedure have shorter midtrimester cervical lengths. Both a prior cervical excisional procedure and a short cervix were independently associated with preterm birth. These data suggest that the risk of preterm birth associated with a prior loop electrosurgical excision procedure or cold knife cone is not merely due to postsurgical shortening of the cervix.

Cervical assessment in women with hysteroscopic uterine septum resection: a retrospective cohort study

OBJECTIVE

To estimate whether cervical length measured by transvaginal ultrasonography in women with a history of hysteroscopic uterine septum resection predicts spontaneous preterm birth <35 weeks' gestation.

METHODS

This retrospective cohort study compared women who had undergone hysteroscopic metroplasty, and were subsequently pregnant with singleton gestations delivered January 2003 to December 2012, to a low-risk control group. Transvaginal ultrasonographic cervical lengths were measured 16-30 weeks' gestation. The primary outcome was spontaneous preterm birth <35 weeks' gestation and the primary exposure variable of interest was cervical length.

RESULTS

Women with a uterine septum resected (N = 24) had a shorter cervical length (2.90 cm) than the low-risk control group (N = 141, 4.31 cm, p < 0.0001); and were more likely to have a cervical length <3.0 cm (41.7% versus 1.4%, p < 0.0001), <2.5 cm (33.3% versus 0%, p < 0.0001), <2.0 cm (16.7% versus 0%, p < 0.0001) and <1.5 cm (12.5% versus 0%, p = 0.003). Women with septum resected were more likely to receive corticosteroids (33.3% versus 11.3%, p = 0.010), but were not more likely to have a spontaneous preterm birth <35 weeks (4.2% versus 0.7%, p = 0.27). There were no differences noted in secondary outcomes including neonatal morbidity.

CONCLUSION

Pregnant women with a history of a hysteroscopic uterine septum resection have shorter cervical lengths than low-risk controls but may not be at a higher risk of spontaneous preterm birth <35 weeks' gestation. Further research with a larger sample size is needed to evaluate this group of women to determine if transvaginal ultrasonographic cervical length assessment is of benefit.

Predictive value of volume of cervical tissue removed during LLETZ on subsequent preterm delivery: a cohort study

OBJECTIVE

To evaluate the impact of volume of tissue removed during large loop excision of transformation zone on subsequent preterm birth rates.

STUDY DESIGN

A retrospective cohort study was carried out in a single, large tertiary referral unit in UK. A total of 556 women who delivered between January 2008 and December 2011 following a previous large loop excision of transformation zone procedure or punch biopsy were identified from the maternity and colposcopy databases. Demographic data, gestational age at delivery, birthweight, neonatal outcome and dimensions of excised cervical specimen were collected. Pregnancy outcomes for women who had a previous loop excision were compared to a matched control group who had undergone punch biopsies only.

RESULTS

There was a significant increase in preterm birth rate in the large loop excision group compared to the control group (9.0% vs. 3.6%, respectively, RR 2.5, 95% CI 1.224-5.107). Women who had undergone at least one previous loop excision had more than a threefold increased risk of spontaneous preterm birth compared with their matched controls. However, no relationship between volume or depth of cervical tissue excised and subsequent gestation at delivery could be demonstrated.

CONCLUSIONS

Whilst LLETZ is associated with an increased rate of preterm birth, the volume of tissue removed does not appear to influence the subsequent gestational age at delivery. This should reassure clinicians who should continue to perform LLETZ with adequate tissue margins to ensure complete resection of disease.

Loop electrosurgical excision procedure and risk of preterm birth: a systematic review and meta-analysis

OBJECTIVE

To assess whether loop electrosurgical excision procedure (LEEP) increases the risk for preterm birth before 37 weeks of gestation and clarify whether the increased risk for preterm birth is attributable to the procedure itself or to risk factors associated with cervical dysplasia.

DATA SOURCES

Two authors performed a search of the relevant data through February 2013 using PubMed, Embase, Scopus, CENTRAL, and ClinicalTrials.gov.

METHODS OF STUDY SELECTION

We included observational studies that compared rates of preterm birth in women with prior LEEP with women with no history of cervical excision. Nineteen of 559 identified studies met selection criteria.

TABULATION, INTEGRATION, AND RESULTS

We compared women with a history of LEEP with two unexposed groups without a history of cervical excision: 1) women with an unknown or no history of cervical dysplasia; and 2) women with a history of cervical dysplasia but no cervical excision. The primary outcome was preterm birth before 37 weeks of gestation. Secondary outcomes were preterm birth before 34 weeks of gestation, spontaneous preterm birth, preterm premature rupture of membranes, and perinatal mortality. DerSimonian-Laird random effects models were used. We assessed heterogeneity between studies using the Q and I tests. Stratified analyses and metaregression were performed to assess confounding. Nineteen studies were included with a total of 6,589 patients with a history of LEEP and 1,415,015 without. Overall, LEEP was associated with an increased risk of preterm birth before 37 weeks of gestation (pooled relative risk 1.61, 95% confidence interval [CI] 1.35-1.92). However, no increased risk was found when women with a history of LEEP were compared with women with a history cervical dysplasia but no cervical excision (pooled relative risk 1.08, 95% CI 0.88-1.33).

CONCLUSION

Women with a history of LEEP have similar risk of preterm birth when compared with women with prior dysplasia but no cervical excision. Common risk factors for both preterm birth and dysplasia likely explain findings of association between LEEP and preterm birth, but LEEP itself may not be an independent risk factor for preterm birth.

Treatment options for high-grade squamous intraepithelial lesions

The introduction of testing for high-risk HPV types and P16 immunostaining of CIN2 histologic specimens allows for determination of the risk of progression versus regression for a woman with a particular cytologic or histologic specimen. Observation with serial cytological or colposcopic examinations is now appropriate for women with low-grade histologic lesions as well as pregnant and young women with certain high-grade histologic lesions. Current recommendations for management of high-grade lesions, the efficacy of treatment options (cryotherapy and LEEP), and the immediate (bleeding, infection) and longer term complications (cervical incompetence, preterm delivery) of cervical dysplasia treatment are presented.

[Prevention of obstetrical complications following LEEP, is it possible?]

Recent epidemiological data suggest an increase of the incidence and prevalence of CIN as well as a decrease of the mean age of the patients presenting these lesions. Large loop electrosurgical procedure (LEEP) is the most commonly used treatment method. According to recent studies LEEP provides a 1.4 to 7.0 fold increase of preterm delivery. Cervical cerclage does not show efficiency in reducing this risk, even if cervical shortening is measured by transvaginal ultrasound. Considering histological severity of lesions and the age of patients, number of currently conducted conizations in France could be avoided and so their obstetrical consequences prevented, just because no treatment is necessary or could be done by ablative procedures.

Pregnancy outcome following loop electrosurgical excision procedure (LEEP) a systematic review and meta-analysis

OBJECTIVE

This study aimed at assessing the association of the relative risk (RR) of adverse pregnancy outcomes with previous treatment of loop electrosurgical excision procedure (LEEP) for the management of cervical intraepithelial neoplasia (CIN).

METHODS

Data sources were from MEDLINE, EMBASE, and SCI citation tracking.

SELECTION CRITERIA

The eligible studies had data on pregnancy outcomes of women with or without previous treatment for CIN. Considered outcomes were severe preterm delivery (<34/32 weeks), extreme preterm delivery (<28 weeks), low birth weight (<2,500 g), stillbirth, preterm spontaneous rupture of membranes, perinatal mortality, and neonatal mortality and induction.

RESULTS

36,954 cases and 1,794,174 controls in 4 prospective cohort and 22 retrospective studies were included in this meta-analysis. LEEP was associated with a higher risk of severe preterm delivery (<32 weeks, relative risk 1.98, 95% CI [1.31, 2.98] 159/11,337 vs. 7,830/860,883), extreme preterm delivery (<28 weeks, RR, 2.33, 95% CI [1.84, 2.94] 97/9,611 vs. 1,559/618,332), preterm premature rupture of the membranes (RR, 1.88, 95% CI [1.54, 2.29] 126/2,837 vs. 7,899/313,094), and low birth weight (<2,500 g, RR, 2.48, 95% CI [1.75, 3.51] 110/1,451 vs. 55/1,742). A cervical length of less than 3 cm was significantly increased in LEEP as compared with that of control group (RR, 4.88, 95% CI [1.56, 15.25]), but increasing LEEP volume or depth was not associated with an increased rate of preterm birth <37 weeks. And LEEP was not associated with a significantly increased risk of perinatal mortality, cesarean section, stillbirth mortality, neonatal mortality, induction, and neonatal intensive care unit admission.

CONCLUSIONS

LEEP is associated with an increased risk of subsequent preterm delivery (<32/34, <28 weeks) and other serious pregnancy outcomes. But increasing LEEP volume or depth is not associated with an increased rate of preterm birth.

Transvaginal ultrasonography to predict preterm birth in women with bicornuate or didelphus uterus

OBJECTIVE

To estimate whether cervical length measured by transvaginal ultrasonography (TVUS) in women with uterine anomalies predicts spontaneous preterm birth (SPTB).

METHODS

This retrospective cohort study compared women with a uterine anomaly who were pregnant with singleton gestations and delivered August 2000 to April 2008 to a low risk control group. Transvaginal ultrasonographic cervical lengths were measured 16-30 weeks gestation. Primary outcome was cervical length and SPTB less than 35 weeks and the primary exposure variable of interest was cervical length. Secondary outcomes were SPTB less than 37 weeks, less than 32 weeks, low birth weight, maternal and neonatal outcomes. Receiver operating characteristic curves were generated to identify the best cervical length cutoff.

RESULTS

Women with a bicornuate uterus (N = 35) had shorter cervical length (3.46 cm) than the low risk control group (N = 122, 4.32 cm, p < 0.0001). Women with a bicornuate or didelphus uterus, compared with low risk women, had higher rates of SPTB less than 35 weeks (8.6% and 30.8% versus 0.8%, p = 0.0007), neonatal intensive care unit admission more than 24 h (26.5% and 41.7% versus 7.5%, p = 0.0021) and composite perinatal morbidity (32.4% and 69.2% versus 8.3%, p < 0.0001). Using a cutoff of 3.0 cm, TVUS cervical length in women with a bicornuate uterus predicted SPTB less than 35 weeks (positive predictive value [PPV] = 37.5% and negative predictive value [NPV] = 100%), birth weight less than 2500 g (PPV = 50.0% and NPV = 96.3%) and respiratory distress syndrome (PPV = 37.5% and NPV = 100%). CONCLUSION Women with a bicornuate uterus have shorter cervical lengths than low risk controls, and are at higher risk of SPTB less than 35 weeks. Transvaginal ultrasonographic cervical length predicts SPTB less than 35 weeks, low birth weight and perinatal morbidity in these women.

Transvaginal sonographic evaluation of the cervix in asymptomatic singleton pregnancy and management options in short cervix

Preterm delivery (PTD), defined as birth before 37 completed weeks of gestation, is the leading cause of perinatal morbidity and mortality. Evaluation of the cervical morphology and biometry with transvaginal ultrasonography at 16–24 weeks of gestation is a useful tool to predict the risk of preterm birth in low- and high-risk singleton pregnancies. For instance, a sonographic cervical length (CL) > 30 mm and present cervical gland area have a 96-97% negative predictive value for preterm delivery at <37 weeks. Available evidence supports the use of progesterone to women with cervical length ≤25 mm, irrespective of other risk factors. In women with prior spontaneous PTD with asymptomatic cervical shortening (CL ≤ 25 mm), prophylactic cerclage procedure must be performed and weekly to every two weeks follow-up is essential. This article reviews the evidence in support of the clinical introduction of transvaginal sonography for both the prediction and management of spontaneous preterm labour.

SOGC Clinical Practice Guideline. Ultrasonographic cervical length assessment in predicting preterm birth in singleton pregnancies

OBJECTIVES

To review (1) the use of ultrasonographic-derived cervical length measurement in predicting preterm birth and (2) interventions associated with a short cervical length.

OUTCOMES

Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions.

EVIDENCE

Published literature was retrieved through searches of PubMed and The Cochrane Library up to December 2009, using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, incompetent cervix, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence and this guideline were reviewed by the Diagnostic Imaging Committee and the Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made according to the guidelines developed by The Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the ultrasonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth.

SPONSORS

The Society of Obstetricians and Gynaecologists of Canada.

Reproducibility of endocervical curettage diagnoses

OBJECTIVE

To estimate overall interobserver variability of histopathology diagnoses on endocervical curettage (ECC) specimens.

METHODS

Five study pathologists, blinded to the original diagnosis, reviewed archived ECC specimens initially interpreted as normal, low-grade dysplasia, and high-grade dysplasia. We assessed interobserver agreement and agreement between pathologists using the κ statistic and analyzed the effect of reducing diagnostic choices to two categories (one method using "normal and dysplasia" and another method using "normal and low-grade" and "high-grade or worse").

RESULTS

A total of 90 specimens were reviewed. The overall observer agreement was moderate (κ = 0.52). For specific diagnoses, cases interpreted as normal or high-grade dysplasia demonstrated greater agreement than those interpreted as low-grade dysplasia. Individual pathologists' comparison κ values ranged from 0.31 to 0.80. Changing diagnostic options to a two-tiered system resulted in significant improvement in κ values for only 1 of 36 pathologist comparisons. Using the gynecologist pathologist consensus interpretation, study pathologists downgraded 44% of cases originally interpreted as high-grade.

CONCLUSION

Interobserver agreement in the interpretation of ECC specimens is at best moderate, even between those with additional experience and training in gynecologic pathology. Furthermore, reducing diagnostic options to two categories did not improve agreement. It is concerning that important clinical decisions may be made based on an ECC diagnosis that is moderately or poorly reproducible.

LEVEL OF EVIDENCE

II.

Cervical conization and the risk of preterm delivery

The current body of literature concerning cervical conization and its effect on subsequent pregnancy outcome is conflicting. Depending on the type of conization procedure that is examined and the quality of the control group, the results and conclusions vary widely. Because treatment for cervical intraepithelial neoplasia is commonplace among women of reproductive age, it is imperative that practitioners have an understanding of the issues surrounding the treatment. Therefore, this review will summarize the published literature that addresses excisional procedures of the uterine cervix and the risk of preterm delivery in subsequent pregnancies and provide reasonable treatment recommendations for women with cervical abnormalities and a desire for future fertility.

Transvaginal ultrasonographic measurement of cervical length in asymptomatic high-risk women with a short cervical length in the previous pregnancy

OBJECTIVE

To determine if asymptomatic women at high risk of preterm delivery who had a short cervical length in their previous pregnancy and delivered at term are at increased risk of having a short cervical length in their next pregnancy, and whether they are at increased risk of preterm birth.

METHODS

This retrospective cohort study included high-risk (those with a history of spontaneous preterm birth, uterine anomaly or excisional treatment for cervical dysplasia) asymptomatic women who were pregnant with a singleton gestation delivering between April 2003 and March 2010, who had had a previous pregnancy and who had transvaginal ultrasonographic cervical length measurement performed at 16-30 weeks' gestation in both pregnancies. Comparison was among women who had a short cervical length (< 3.0 cm) in their previous pregnancy but delivered at term in that pregnancy (Short Term Group), women with a history of a normal cervical length (≥ 3.0 cm) in their previous pregnancy delivering at term (Long Term Group), and women who had a short cervical length (< 3.0 cm) in their previous pregnancy delivering preterm (Short Preterm Group). Primary outcomes were spontaneous preterm birth at < 37 weeks' gestation and cervical length. Secondary outcomes were spontaneous preterm birth at < 35 weeks and < 32 weeks, low birth weight, maternal outcomes and neonatal morbidity.

RESULTS

A total of 62 women were included. Women in the Short Term Group were more likely to have a short cervical length in their next pregnancy compared with those in the Long Term Group (10/23 (43.5%) vs. 4/26 (15.4%), respectively) but not as likely as women in the Short Preterm Group (9/13 (69.2%); P=0.003). Women in the Short Term Group were not at an increased risk of spontaneous preterm birth at < 37 weeks in the next pregnancy compared with women in the Long Term Group (2/23 (8.7%) vs. 2/26 (7.7%), respectively), but women in the Short Preterm Group were at an increased risk (6/13 (46.2%); P<0.0001). Compared with women in the Short Term and Long Term groups, women in the Short Preterm Group were also at an increased risk of threatened preterm labor (6/23 (26.1%) and 4/26 (15.4%) vs. 9/13 (69.2%), respectively; P=0.002) and of receiving corticosteroids for fetal lung maturation (6/23 (26.1%) and 4/26 (15.4%) vs. 11/13 (84.6%), respectively; P<0.0001).

CONCLUSION

Although high-risk asymptomatic women with a short cervical length in their previous pregnancy who delivered at term are at increased risk of having a short cervix in their next pregnancy, they are not at increased risk of preterm birth.

Follow-up cervical length in asymptomatic high-risk women and the risk of spontaneous preterm birth

OBJECTIVE

To determine whether further cervical length shortening by transvaginal ultrasonography in asymptomatic high-risk women with a short cervical length adds additional predictive value for spontaneous preterm birth and perinatal morbidity.

STUDY DESIGN

Women with a history of spontaneous preterm birth, loop electrosurgical excision procedure, cone biopsy or uterine anomaly, who were pregnant with singleton gestations and were found by transvaginal ultrasonography to have a cervical length <3.0 cm at 20 to 28 weeks' gestation, and who underwent a follow-up cervical length within 3 weeks were evaluated, comparing those with further cervical length shortening (>10%) to those without further shortening. Primary outcomes were spontaneous preterm birth <35 weeks' gestation and perinatal morbidity. Secondary outcomes included spontaneous preterm birth <37 weeks, <34 weeks, <32 weeks, birth weight <2500 g, maternal and other neonatal outcomes.

RESULT

Compared with women without further cervical shortening, those with further shortening were found by univariate analyses to have higher rates of spontaneous preterm birth <35 weeks (34.8 versus 8.5%, P = 0.014), <37 weeks (56.5 versus 21.3%, P = 0.003), <34 weeks (30.4 versus 2.1%, P = 0.001), <32 weeks (21.7 versus 0%, P = 0.003), birth weight <2500 g (60.9 versus 17.0%, P<0.0001), neonatal intensive care unit admission (47.8 versus 17.0%, P = 0.006) and composite perinatal morbidity (43.5 versus 14.9%, P = 0.009). Logistic regression revealed the only independent predictors of spontaneous preterm birth <35 weeks were further cervical length shortening (adjusted odds ratio (aOR) 5.73; 95% confidence interval (CI) 1.31 to 24.43) and gestational age at short cervical length (aOR 0.95; 95% CI 0.91 to 0.99).

CONCLUSION

Further cervical length shortening in asymptomatic high-risk women with a short cervical length is an important independent predictor of spontaneous preterm birth <35 weeks and perinatal morbidity.

Effects of photodynamic therapy using topical applied hexylaminolevulinate and methylaminolevulinate upon the integrity of cervical epithelium

BACKGROUND AND OBJECTIVE

Cervical intraepithelial neoplasia (CIN) is associated with genital human papillomavirus (HPV) infection and represents the precursor of cervical cancer. Established ablative treatment methods may cause substantial complications in following pregnancies including premature delivery and the birth of low-weight babies. Photodynamic therapy (PDT) of CIN using esters of 5-aminolevulinic acid (5-ALA) represents a promising alternative. However, it has not been analyzed yet if the PDT itself leads to sustained damage of the cervical tissue. This study aims at evaluating the effect of hexylaminolevulinate (HAL) and methylaminolevulinate (MAL) PDT on cervical tissue.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-five patients underwent 1-2 PDT cycles for CIN 1-3 applying topical HAL and MAL. Before and 6 months after PDT, biopsies were obtained from the cervix. Macroscopic changes of the cervix were evaluated. We assessed H&E slides for signs of sustained tissue damage. Furthermore, expression profiles of p16(INK4a), Ki67, Bcl-2, Bax, and CD31 were evaluated.

RESULTS

PDT was performed satisfactory in all patients. No macroscopic changes of the cervix were encountered and histological evaluation revealed no signs of apoptosis, necrosis, irritation, vascular changes and fibroses 6 months after PDT. Ki67 and p16(INK4a) were useful for the prediction of response to PDT. Bcl-2 and Bax showed no significant expression profile changes after PDT and the micro-vessel pattern was not altered.

CONCLUSIONS

HAL and MAL PDT do not leave any sustained damage in normal cervical tissue. This is of paramount importance as cervical insufficiency or stenosis may have implications on pregnancy and cervical cancer screening.