The risk of preterm birth of treated versus untreated cervical intraepithelial neoplasia (CIN): a systematic review and meta-analysis

Risk factors for preterm birth: an umbrella review of meta-analyses of observational studies

BACKGROUND

Preterm birth defined as delivery before 37 gestational weeks is a leading cause of neonatal and infant morbidity and mortality. The aim of this study is to summarize the evidence from meta-analyses of observational studies on risk factors associated with PTB, evaluate whether there are indications of biases in this literature, and identify which of the previously reported associations are supported by robust evidence.

METHODS

We searched PubMed and Scopus until February 2021, in order to identify meta-analyses examining associations between risk factors and PTB. For each meta-analysis, we estimated the summary effect size, the 95% confidence interval, the 95% prediction interval, the between-study heterogeneity, evidence of small-study effects, and evidence of excess-significance bias. Evidence was graded as robust, highly suggestive, suggestive, and weak.

RESULTS

Eighty-five eligible meta-analyses were identified, which included 1480 primary studies providing data on 166 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections, and vaccines. Ninety-nine (59.3%) associations were significant at P < 0.05, while 41 (24.7%) were significant at P < 10-6. Ninety-one (54.8%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 37 (22.3%) and 12 (7.2%) associations, respectively. We evaluated all associations according to prespecified criteria. Seven risk factors provided robust evidence: amphetamine exposure, isolated single umbilical artery, maternal personality disorder, sleep-disordered breathing (SDB), prior induced termination of pregnancy with vacuum aspiration (I-TOP with VA), low gestational weight gain (GWG), and interpregnancy interval (IPI) following miscarriage < 6 months.

CONCLUSIONS

The results from the synthesis of observational studies suggest that seven risk factors for PTB are supported by robust evidence. Routine screening for sleep quality and mental health is currently lacking from prenatal visits and should be introduced. This assessment can promote the development and training of prediction models using robust risk factors that could improve risk stratification and guide cost-effective preventive strategies.

TRIAL REGISTRATION

PROSPERO 2021 CRD42021227296.

Screening for Cervical Cancer in Pregnancy

Cervical cancer remains a leading cause of cancer related morbidity and mortality in low/low-middle income countries. Lack of screening is the leading cause of cases being diagnosed in advanced stages and screening is still opportunistic in a majority of these countries. Hospital visits during pregnancy provides a window of opportunity to screen these susceptible women and reduce the burden of disease. Screening women during pregnancy is not practiced widely due to concerns of pregnancy loss, bleeding and a lack of clear information among patients as well as healthcare professionals.

Risk factors for preterm labor: An Umbrella Review of meta-analyses of observational studies

Preterm birth defined as delivery before 37 gestational weeks, is a leading cause of neonatal and infant morbidity and mortality. Understanding its multifactorial nature may improve prediction, prevention and the clinical management. We performed an umbrella review to summarize the evidence from meta-analyses of observational studies on risks factors associated with PTB, evaluate whether there are indications of biases in this literature and identify which of the previously reported associations are supported by robust evidence. We included 1511 primary studies providing data on 170 associations, covering a wide range of comorbid diseases, obstetric and medical history, drugs, exposure to environmental agents, infections and vaccines. Only seven risk factors provided robust evidence. The results from synthesis of observational studies suggests that sleep quality and mental health, risk factors with robust evidence should be routinely screened in clinical practice, should be tested in large randomized trial. Identification of risk factors with robust evidence will promote the development and training of prediction models that could improve public health, in a way that offers new perspectives in health professionals.

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.

Comparative fertility and pregnancy outcomes after local treatment for cervical intraepithelial neoplasia and stage 1a1 cervical cancer: protocol for a systematic review and network meta-analysis from the CIRCLE group

INTRODUCTION

There are several local treatment methods for cervical intraepithelial neoplasia that remove or ablate a cone-shaped part of the uterine cervix. There is evidence to suggest that these increase the risk of preterm birth (PTB) and that this is higher for techniques that remove larger parts of the cervix, although the data are conflicting. We present a protocol for a systematic review and network meta-analysis (NMA) that will update the evidence and compare all treatments in terms of fertility and pregnancy complications.

METHODS AND ANALYSIS

We will search electronic databases (CENTRAL, MEDLINE, EMBASE) from inception till October 2019, in order to identify randomised controlled trials (RCTs) and cohort studies comparing the fertility and pregnancy outcomes among different excisional and ablative treatment techniques and/or to untreated controls. The primary outcome will be PTB (<37 weeks). Secondary outcomes will include severe or extreme PTB, prelabour rupture of membranes, low birth weight (<2500 g), neonatal intensive care unit admission, perinatal mortality, total pregnancy rates, first and second trimester miscarriage. We will search for published and unpublished studies in electronic databases, trial registries and we will hand-search references of published papers. We will assess the risk of bias in RCTs and cohort studies using tools developed by the Cochrane collaboration. Two investigators will independently assess the eligibility, abstract the data and assess the risk of bias of the identified studies. For each outcome, we will perform a meta-analysis for each treatment comparison and an NMA once the transitivity assumption holds, using the OR for dichotomous data. We will use CINeMA (Confidence in Network meta-analysis) to assess the quality of the evidence for the primary outcome.

ETHICS AND DISSEMINATION

Ethical approval is not required. Results will be disseminated to academic beneficiaries, medical practitioners, patients and the public.

PROSPERO REGISTRATION NUMBER

CRD42018115495.

HIV serostatus, viral load, and midtrimester cervical length in a Zambian prenatal cohort

OBJECTIVE

To evaluate whether maternal HIV serostatus and plasma viral load (VL) are associated with midtrimester cervical length (CL).

METHODS

The Zambian Preterm Birth Prevention Study (ZAPPS) is an ongoing prospective cohort that began enrolling in Lusaka in August 2015. Pregnant women undergo ultrasound to determine gestational age and return for CL measurement at 16-28 weeks. We evaluated crude and adjusted associations between dichotomous indicators and short cervix (≤2.5 cm) via logistic regression, and between VL and CL as a continuous variable via linear regression.

RESULTS

This analysis includes 1171 women enrolled between August 2015 and September 2017. Of 294 (25.1%) HIV-positive women, 275 (93.5%) had viral load performed close to CL measurement; of these, 148 (53.8%) had undetectable virus. Median CL was 3.6 cm (IQR 3.5-4.0) and was similar in HIV-infected (3.7 cm, IQR 3.5-4.0) versus uninfected (3.6 cm, IQR 3.5-4.0) participants (P=0.273). The odds of short CL were similar by HIV serostatus (OR 0.64; P=0.298) and detectable VL among those infected (OR 2.37, P=0.323). We observed no association between log VL and CL via linear regression (-0.12 cm; P=0.732).

CONCLUSION

We found no evidence of association between HIV infection and short CL.

Obstetric outcomes in patients who have undergone excisional treatment for high-grade cervical squamous intra-epithelial neoplasia

OBJECTIVE

To evaluate the relationships between excisional treatment for high-grade cervical intra-epithelial neoplasia (CIN2+) and obstetric outcomes in terms of preterm delivery risk, premature rupture of membrane (PROM) and type of delivery, and between pre-term delivery and the type of excisional technique (radio frequency excision, laser conization).

METHODS

This was a retrospective study of the obstetric outcomes of 2316 women aged 25-45 years who underwent excisional treatment for CIN2+ at the Obstetric and Gynecological Clinic of Ospedale Maggiore della Carità in Novara and at the Obstetric and Gynecological Department of Ospedale Sant'Anna in Torino in the period 2005-2014 and were evaluated until April 2016, and 57,937 untreated women of the same age, from the same centers.

RESULTS

After treatment, 320 women had at least one pregnancy leading to delivery after a mean of 3.35 years. Treatment significantly increased the risk of preterm delivery. Compared with no treatment, the risk of preterm birth was higher in women who had undergone treatment (33.13% vs. 6.60%). Techniques removing or ablating more tissue, such as large loop excision of the transformation zone, were associated with worse outcomes (OR 2.96, 95% IC 1.72-5.10). Smoking habits significantly increase the risk of preterm delivery in the treated women (OR 2.82, 95% IC 1.61-4.9). The risk of premature rupture of the membranes (PROM) (40% vs. 23.22%), the risk of preterm PROM (pPROM) (13.13% vs. 2.71%) and dystocic births (18.75% vs 4.48%) were also significantly increased after treatment. Caesarean sections were less frequent among the treated women (15.94% vs. 32.41%).

CONCLUSIONS

Our findings reveal a relationship between cervical excisional treatment and pre-term delivery, PROM, and the method of delivery. In order to minimise risk and guarantee the best obstetric outcome, patient treatment and follow-up should be personalised.

Natural History of Cervical Intraepithelial Neoplasia-2 in HIV-Positive Women of Reproductive Age

OBJECTIVE

To evaluate the natural history of treated and untreated cervical intraepithelial neoplasia-2 (CIN2) among HIV-positive women.

METHODS

Participants were women enrolled in the Women's Interagency HIV Study between 1994 and 2013. One hundred four HIV-positive women diagnosed with CIN2 before age 46 were selected, contributing 2076 visits over a median of 10 years (interquartile range 5-16). The outcome of interest was biopsy-confirmed CIN2 progression, defined as CIN3 or invasive cervical cancer. CIN2 treatment was abstracted from medical records.

RESULTS

Most women were African American (53%), current smokers (53%), and had a median age of 33 years at CIN2 diagnosis. Among the 104 HIV-positive women, 62 (59.6%) did not receive CIN2 treatment. Twelve HIV-positive women (11.5%) showed CIN2 progression to CIN3; none were diagnosed with cervical cancer. There was no difference in the median time to progression between CIN2-treated and CIN2-untreated HIV-positive women (2.9 vs. 2.7 years, P = 0.41). CIN2 treatment was not associated with CIN2 progression in multivariate analysis (adjusted hazard ratio 1.82; 95% confidence interval: 0.54 to 7.11), adjusting for combination antiretroviral therapy and CD4 T-cell count. In HIV-positive women, each increase of 100 CD4 T cells was associated with a 33% decrease in CIN2 progression (adjusted hazard ratio 0.67; 95% confidence interval: 0.47 to 0.88), adjusting for CIN2 treatment and combination antiretroviral therapy.

CONCLUSIONS

CIN2 progression is uncommon in this population, regardless of CIN2 treatment. Additional studies are needed to identify factors to differentiate women at highest risk of CIN2 progression.

[Pathoanatomical and clinical aspects of the placenta in preterm birth]

BACKGROUND

Prematurely born children show a clearly elevated risk for perinatal morbidity, long-term pediatric morbidities and development of chronic diseases in adulthood compared to babies born at term. The pathoanatomical investigation of placentas from preterm births is useful for assessing the etiology, the risk of recurrence and the prognosis for the child.

AIMS

The focus is on presenting the clinical and pathoanatomical characteristics of acute chorioamnionitis as a frequent cause of preterm induction of labor and pregnancy-induced hypertension, in particular preeclampsia as a frequent reason for elective cesarean section. Other lesions, sometimes of unclear etiology associated with preterm birth and substantially elevated risk of recurrence are reviewed. The clinical correlations and therapeutic options of the various diseases are discussed taking the risk of recurrence into consideration.

MATERIAL AND METHODS

Examination of placentas, association with the clinical course and a literature search.

RESULTS AND DISCUSSION

Acute chorioamnionitis and omphalovasculitis can be histologically subdivided into different stages which correlate with the clinical severity and the prognosis for the newborn child. Chronic deciduitis, chronic chorioamnionitis, villitis of unknown etiology, massive perivillous fibrin deposition and chronic histiocytic intervillositis are entities of unclear etiology associated with recurrent abortion and preterm birth. Autoimmune diseases and thrombophilia are occasionally associated with these pathologically defined lesions. Pregnancy-associated hypertensive disease and particularly preeclampsia as the cause of intrauterine developmental delay and elective cesarean section often show characteristic pathoanatomical placental lesions, which can give indications for the severity and duration of the disease and the prognosis for the child. Early onset (<34 weeks of gestation) and late onset preeclampsia show clinical and morphological differences. Subsequent pregnancies are classified as being at risk and screening for preeclampsia should be clinically performed.

Effect of age and cone dimensions on cervical regeneration: an Italian multicentric prospective observational study

OBJECTIVES

To evaluate cervical regeneration at 6 months following excisional treatment for high-grade cervical intraepithelial neoplasia (CIN), and to investigate the effect of cone dimensions, age of patients and technique of excision on the efficacy of the regeneration process.

DESIGN

Prospective observational multicentric study.

SETTING

Three tertiary care and research centres.

PARTICIPANTS

Among the 197 eligible women of childbearing age, older than 25 years of age, undergoing for the first time a loop electrosurgical excision procedure or carbon dioxide laser cervical excision for a high-grade CIN at the colposcopy-directed cervical punch biopsy, and with a final diagnosis of high-grade CIN, 165 completed the 6-month follow-up and were included in the analysis.

PRIMARY OUTCOME MEASURES

The cervical length and volume regeneration (%) after 6 months from procedure were determined by three-dimensional ultrasound, and the correlation of regeneration with cone dimensions, age and excision technique was evaluated.

RESULTS

The mean±SD cervical length regeneration at 6 months was 89.5%±6.3% and the mean±SD cervical volume regeneration was 86.3%±13.2%. At the multivariate analysis, a significant and independent inverse correlation between excised cone length and cervical regeneration emerged (r=-0.39, P<0.001). A significantly negative trend in length regeneration at 6 months from procedure with an increasing class of cone length was found (P<0.001). No significant association was found in relation with patient age at the time of procedure or with the technique of excision.

CONCLUSIONS

Cervical length regeneration at 6 months from excisional treatments is negatively affected by an increasing cone length but not from the age of the patient or the technique of excision. While still achieving equal clinical efficacy, it is crucial to contain cone dimensions, in order to favour a greater length regeneration, reducing the cervical harm and the potential future obstetric complications.

Effect of Cervical Cancer Screening Programs on Preterm Birth: A Decision and Cost-Effectiveness Analysis

OBJECTIVE

To assess the effect of age at initiation and interval of cervical cancer screening in women of reproductive age on the risk of future preterm birth and subsequent adverse neonatal outcome relative to maternal life-years gained and cost of both screening and preterm birth.

METHODS

In this decision and cost-effectiveness analysis, we compared eight cytology-based screening programs varying in age of onset (21, 24, 25, 27, or 30 years) and screening interval (3 or 5 years) in a fictive cohort of 100,000 women. We used the microsimulation screening analysis model to estimate number of cervical intraepithelial neoplasia diagnoses, large loop excisions of the transformation zone (LLETZs), life-years gained, cervical cancer cases, deaths, and costs of screening and treatment. We used the number of LLETZs to calculate additional preterm births, subsequent neonatal morbidity, mortality, and associated costs.

RESULTS

The number of LLETZs per 100,000 women varied from 9,612 for the most intensive screening (every 3 years from age 21 years) to 4,646 for the least intensive screening (every 5 years from age 30 years). Compared with the least intensive program, the most intensive program increased maternal life-years gained by 9% (10,728 compared with 9,839), decreased cervical cancer cases by 67% (52 compared with 158), and cervical cancer deaths by 75% (four compared with 16) at the expense of 250% (158 compared with 45) more preterm births and 320% (four compared with one) more neonatal deaths while increasing total costs by $55 million ($77 compared with $23 million). The number of maternal life-years gained per additional preterm birth varied from 68 to 258 with subsequent total costs per maternal life-years gained of $7,212 and $2,329.

CONCLUSION

Cervical cancer screening every 3 years and subsequent treatment in women aged younger than 30 years yield limited life-years but may have substantial perinatal adverse effects. Consequently, women who plan to have children may benefit from a more cautious screening approach, taking into account their risk for both cancer and preterm birth.

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.

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.

Clinical relevance and implications of HPV-induced neoplasia in different anatomical locations

Human papillomaviruses (HPV) are widespread DNA viruses that can infect epithelial cells of the skin and mucosa. Most HPV infections remain clinically unapparent and clear spontaneously. In few cases, however, HPV infections persist and can cause benign and malignant neoplasms at different anatomic locations. Malignant HPV-induced neoplasms are caused by distinct types of HPV (oncogenic or high-risk (HR) HPV types) and present in the anogenital (anus, penis, uterine cervix, vagina and vulva) and head and neck (particularly oropharynx) region. In the anogenital region defined precancerous stages precede invasive cancer. In the head and neck region there is clear evidence only for the invasive stage of HPV-induced neoplasia. In early infection stages the HPV oncogenes (E6/E7) are under tight control in the basal and parabasal cell layers. In more advanced precancerous stages increased expression of the HPV oncogenes E6 and E7 occurs (transforming infection) that may result in transformation of these cells. The defined carcinogenesis in the anogenital tract enables cancer early detection, particularly at the uterine cervix where cytologic and molecular tests contribute to early diagnosis and treatment at a non-invasive stage. Up to now, the treatment of HPV-related precancerous stages (high-grade intraepithelial neoplasia) and cancer is not specifically targeting molecular characteristics of the virus. This article reviews the current state and new developments in epidemiology, prevention, diagnosis and treatment of HPV-associated neoplasia in various anatomic locations.

Risk assessment and management to prevent preterm birth

Preterm birth is the most important cause of neonatal mortality and morbidity worldwide. In this review, we review potential risk factors associated with preterm birth and the subsequent management to prevent preterm birth in low and high risk women with a singleton or multiple pregnancy. A history of preterm birth is considered the most important risk factor for preterm birth in subsequent pregnancy. General risk factors with a much lower impact include ethnicity, low socio-economic status, maternal weight, smoking, and periodontal status. Pregnancy-related characteristics, including bacterial vaginosis and asymptomatic bacteriuria, appear to be of limited value in the prediction of preterm birth. By contrast, a mid-pregnancy cervical length measurement is independently associated with preterm birth and could be used to identify women at risk of a premature delivery. A fetal fibronectin test may be of additional value in the prediction of preterm birth. The most effective methods to prevent preterm birth depend on the obstetric history, which makes the identification of women at risk of preterm birth an important task for clinical care providers.