Pregnancy incidence and outcome among patients with cervical intraepithelial neoplasia: a retrospective cohort study

Impact of cervical intraepithelial neoplasia and treatment on IVF/ICSI outcomes

STUDY QUESTION

Does treatment selection for cervical lesions affect the outcome of IVF/ICSI?

SUMMARY ANSWER

There was no difference in pregnancy outcome between treated and untreated groups, or between different types of IVF/ICSI treatment.

WHAT IS KNOWN ALREADY

Human papillomavirus (HPV) infection and HPV-induced cervical lesions are associated with decreased fertility, and cervical intraepithelial neoplasia (CIN) treatment may increase the risk of adverse pregnancy outcomes.

STUDY DESIGN, SIZE, DURATION

Between 2018 and 2020, 190 women with infertility who had abnormal HPV screening or cytology results prior to IVF/ICSI, and were diagnosed with CIN2/CIN3 by colposcopy biopsy at a tertiary hospital, were enrolled in a retrospective cohort study with follow-up until 31 December 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients with infertility who were diagnosed with CIN2/CIN3 by colposcopy biopsy were divided into the treatment and expectant management groups. The treatment group was divided into two intervention subgroups: the ablative therapy group and the surgical treatment group. The baseline data, number of oocytes retrieved, and rates of fertilization, high-quality embryos, positive serum HCG, clinical pregnancy, abortion, live birth, and cumulative pregnancy were compared among groups.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 190 patients included in the study, 152 were diagnosed with CIN2, and 38 patients had CIN3. There was no significant difference in the baseline data between the treatment and expectant groups. The time from confirmed lesions to the onset of gonadotrophin administration in the surgical treatment group was significantly longer than in the ablative therapy group and the expectant group (P = 0.007 and P = 0.024, respectively). For the treatment and expectant groups, respectively, the average number of oocytes retrieved (12.95 ± 8.77; 13.32 ± 9.16), fertilization rate (71.01 ± 23.86; 64.84 ± 26.24), and high-quality embryo rate (48.93 ± 30.72; 55.17 ± 34.13) did not differ, and no differences were detected between the different treatment subgroups. There were no differences among groups in rates of HCG positivity, clinical pregnancy, miscarriage, live birth, or cumulative pregnancy. The live birth rate in the surgical treatment group was slightly higher than that in the expectant groups (77.78% versus 66.67%), but the difference was not statistically significant. The 3-year cumulative pregnancy rates in the surgical treatment and expectant groups were 58.19% and 64.00%, respectively.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study, which by nature can include selection bias, and the number of cases in the expectant group was <30, which may result in a false-negative result owing to the small sample size.

WIDER IMPLICATIONS OF THE FINDINGS

For patients with CIN2/CIN3, the treatment of cervical lesions does not affect the outcome of IVF/ICSI. Patients with CIN2 can enroll for IVF/ICSI cycles, with close follow-up to prevent the progression of cervical lesions, in order to avoid further delay in starting ART. For patients with CIN3, ovulation induction and embryo cryopreservation can be initiated as soon as possible after cervical lesions are treated, and frozen-thawed embryo transfer can be carried out 9-12 months later.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the Key Clinical Projects of the Peking University Third Hospital (to Y.W., BYSYZD2021014). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

How endocervicoscopy can impact obstetric outcomes in women undergoing LEEP for CIN2 + : a retrospective cohort analysis

PURPOSE

To assess the impact of preoperative endocervicoscopy on obstetric outcomes and complications in women undergoing LEEP for CIN2 + .

METHODS

This was a retrospective cohort study carried out between October 2012 and April 2018. All women had undergone cervical length measurement at T0 (before LEEP), T1 (6 months after LEEP), and T2 (at 20 weeks of pregnancy) through transvaginal ultrasound examination after LEEP for CIN2 + . A total of 528 patients fulfilled our inclusion criteria and contributed to the final analysis: 288 had undergone endocervicoscopy before the excisional procedure (Group A), while the remaining 240 (Group B) did not.

RESULTS

Patients who did not undergo endocervicoscopy showed a greater amount of tissue excised at LEEP compared to those of Group A (6.7% vs 31.9% in Group A and B, p < 0.01, respectively). A statistically relevant difference was detected in the lesion margins involvement: negative in 93.8% in Group A compared to 65.6% in Group B. The cervicometry before the treatment resulted in similar between the two groups, while a statistically significant difference was noted after 6 months (37.5 ± 2.9 mm in Group A vs 35.1 ± 3.8 mm in Group B, p < 0.01) and at 20th week pregnancy (36.9 ± 5.3 mm in Group A vs 33.5 ± 5.6 mm in Group B, p < 0.01). The number of pregnancies after LEEP as well as the difference in the elapsed time (in months) did not result in a statistical significance between the two groups. The threatened preterm labor (TPL) and the threatened miscarriage showed a statistically significant difference in incidence between the two groups (4,2% and 4.2% in Group A vs 15.3% and 25% in Group B, p < 0.01, respectively).

CONCLUSION

Endocervicoscopy reduces the size of the LEEP sample and in particular its depth, saving healthy cervical tissue, and guarantees the total eradication of the lesion as the resection margins are negative in almost all cases, allowing for a reduction of the rate of TPL and threatened miscarriage in women with CIN2 + , especially with Type 2 or 3 cervical squamocolumnar junction (SCJ).

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.

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.

The Effect of Vaccination Against Human Papillomavirus on Fecundability

BACKGROUND

The human papillomavirus (HPV) vaccine was developed to prevent infection with strains of HPV that cause cervical cancer. While HPV infection has been associated with reduced semen quality and lower pregnancy rates in some studies, no studies have examined the relationship between HPV vaccination and fecundability. We hypothesize that HPV prevention via vaccination will protect fecundity.

METHODS

We analysed data from Pregnancy Study Online (PRESTO), a preconception cohort of North American pregnancy planners. Between 2013 and 2017, we followed 3483 female pregnancy planners and 1022 of their male partners for 12 months or until reported pregnancy, whichever came first. At baseline, participants reported whether they had been vaccinated against HPV and their age at vaccination. We estimated fecundability ratios (FR) and 95% confidence intervals (CI) using proportional probabilities models adjusted for sociodemographics, smoking, and abnormal Pap test before HPV vaccination (females only).

RESULTS

HPV vaccination was more prevalent among females (33.9%) than males (5.2%). There was little overall association between female vaccination (FR 0.98, 95% CI 0.90, 1.08) or male vaccination (FR 1.07, 95% CI 0.79, 1.46) and fecundability. Among females with a history of sexually transmitted infections or pelvic inflammatory disease (i.e. a group at high risk of exposure to HPV infection), those vaccinated against HPV had higher fecundability than those not vaccinated (FR 1.35, 95% CI 0.99, 1.86).

CONCLUSION

Although HPV vaccination had little effect on fecundability overall, HPV vaccination was positively associated with fecundability among women with a history of sexually transmitted infections.

Cervical Conization and the Risk of Preterm Birth: A Population-Based Multicentric Trial of Turkish Cohort

INTRODUCTION

Cold Knife Conization (CKC) is one of the most effective methods for the treatment of Cervical Intraepithelial Neoplasia (CIN). Some studies showed a relation between preterm birth and the treatment of CIN; on the other hand, other studies do not show such a relationship.

AIM

The present study was conducted with the aim to investigate the pregnancy outcomes of Turkish women regarding demographic characteristics, obstetric history, removed tissue, and residual cervical length after CKC and to determine the effect of removed cervical tissue volume and height on preterm birth.

MATERIALS AND METHODS

This study was a population-based, multicenter trial that was conducted on singleton pregnancies between January 2007 and December 2013. The control group comprised of 38,892 patients who gave birth during this period. On the other hand, patients who conceived after CKC during this period were invited to the hospital and included in the case group (n=20). The course of pregnancy following CKC was studied. Preterm birth rates, risk factors for preterm birth, conisation age, cervical smear and colposcopic biopsy results and the volume and height of the removed cervical tissue of those patients were evaluated.

RESULTS

There was no statistically significant difference in preterm birth rates between the case and the control groups. None of our cases had any identified preterm birth risk factor except for one case. The average height of removed cervical tissue was 12.6±5.4 mm and the average length of the residual cervix after birth was 28.7±4.3 mm.

CONCLUSION

Removal of cervical tissue of 12.6±5.4 mm in height and 2.35±2.27 cm³ in volume will not increase the risk of preterm birth of women who do not have any other preterm birth risk factors. If there is no other preterm birth risk factors, term birth is most probably possible after conisation.

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.

Fertility and early pregnancy outcomes after conservative treatment for cervical intraepithelial neoplasia

BACKGROUND

Cervical intra-epithelial neoplasia (CIN) typically occurs in young women of reproductive age. Although several studies have reported the impact that cervical conservative treatment may have on obstetric outcomes, there is much less evidence for fertility and early pregnancy outcomes.

OBJECTIVES

To assess the effect of cervical treatment for CIN (excisional or ablative) on fertility and early pregnancy outcomes.

SEARCH METHODS

We searched in January 2015 the following databases: the Cochrane Gynaecological Cancer Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, Issue 12, 2014), MEDLINE (up to November week 3, 2014) and EMBASE (up to week 52, 2014).

SELECTION CRITERIA

We included all studies reporting on fertility and early pregnancy outcomes (less than 24 weeks of gestation) in women with a history of CIN treatment (excisional or ablative) as compared to women that had not received treatment.

DATA COLLECTION AND ANALYSIS

Studies were classified according to the treatment method used and the fertility or early pregnancy endpoint. Pooled risk ratios (RR) and 95% confidence intervals (CI) were calculated using a random-effects model and inter-study heterogeneity was assessed with I(2). Two review authors (MK, AM) independently assessed the eligibility of retrieved papers and risk of bias. The two review authors then compared their results and any disagreements were resolved by discussion. If still unresolved, a third review author (MA) was involved until consensus was reached.

MAIN RESULTS

Fifteen studies (2,223,592 participants - 25,008 treated and 2,198,584 untreated) that fulfilled the inclusion criteria for this review were identified from the literature search. The meta-analysis demonstrated that treatment for CIN did not adversely affect the chances of conception. The overall pregnancy rate was higher for treated (43%) versus untreated women (38%; RR 1.29, 95% CI 1.02 to 1.64; 4 studies, 38,050 participants, very low quality), although the inter-study heterogeneity was considerable (P < 0.01). The pregnancy rates in treated and untreated women with an intention to conceive (88% versus 95%, RR 0.93, 95% CI 0.80 to 1.08; 2 studies, 70 participants, very low quality) and the number of women requiring more than 12 months to conceive (14% versus 9%, RR 1.45, 95% CI 0.89 to 2.37; 3 studies, 1348 participants, very low quality) were no different. Although the total miscarriage rate (4.6% versus 2.8%, RR 1.04, 95% CI 0.90 to 1.21; 10 studies, 39,504 participants, low quality) and first trimester miscarriage rate (9.8% versus 8.4%, RR 1.16, 95% CI 0.80 to 1.69, 4 studies, 1103 participants, low quality) was similar for treated and untreated women, CIN treatment was associated with an increased risk of second trimester miscarriage, (1.6% versus 0.4%, RR 2.60, 95% CI 1.45 to 4.67; 8 studies, 2,182,268 participants, low quality). The number of ectopic pregnancies (1.6% versus 0.8%, RR 1.89, 95% CI 1.50 to 2.39; 6 studies, 38,193 participants, low quality) and terminations (12.2% versus 7.4%, RR 1.71, 95% CI 1.31 to 2.22; 7 studies, 38,208 participants, low quality) were also higher in treated women.The results should be interpreted with caution. The included studies were often small with heterogenous design. Most of these studies were retrospective and of low or very low quality (GRADE assessment) and were therefore prone to bias. Subgroup analyses for the individual treatment methods and comparison groups and analysis to stratify for the cone length was not possible.

AUTHORS' CONCLUSIONS

This meta-analysis suggests that treatment for CIN does not adversely affect fertility, although treatment was associated with an increased risk of miscarriage in the second trimester. These results should be interpreted with caution as the included studies were non-randomised and many were of low or very low quality and therefore at high risk of bias. Research should explore mechanisms that may explain the increase in mid-trimester miscarriage risk and stratify this impact of treatment by the length of the cone and the treatment method used.

Pregnancy incidence and outcome before and after cervical intraepithelial neoplasia: a retrospective cohort study

We performed a retrospective cohort study of 3530 women treated for cervical intraepithelial neoplasia (CIN) in Helsinki University Central Hospital, Finland, to investigate whether CIN treatment itself affects pregnancy incidence and outcome. We estimated the incidence of live births, miscarriages, extrauterine pregnancies, molar pregnancies, and termination of pregnancies (TOPs) before and after CIN treatment using nationwide registers. Women were followed up until death, emigration, sterilization, or the end of 2004. The comparison of incidence of pregnancy outcomes before and after the treatment was estimated by calculating hazard ratios (HRs) with conditional Poisson regression. After 76,162 woman-years of follow-up, the incidence of any pregnancy remained constant over CIN-treatment, HR 1.02 and 95% confidence interval (CI) 0.97-1.08, but the incidence of the first pregnancy was significantly elevated after treatment, HR 1.13, and 95% CI 1.03-1.23. The incidence of live births was significantly elevated after treatment, HR 1.08 and 95% CI 1.01-1.15. Incidence of miscarriages, TOPs, extrauterine pregnancies, and molar pregnancies was not elevated. TOPs was significantly increased in the first pregnancy, HR 1.40, 95% CI 1.15-1.72 and after treatment by the loop electrosurgical excision procedure (LEEP), HR 1.36, 95% CI 1.15-1.60. CIN treatment did not reduce pregnancy incidence and women had more live births after than before CIN treatment. TOPs was more common in the first pregnancy or after treatment by LEEP. We encourage research on the psychosocial consequences of CIN treatment also in other countries and settings.

Fertility and early pregnancy outcomes after treatment for cervical intraepithelial neoplasia: systematic review and meta-analysis

OBJECTIVE

To determine the impact of cervical excision for cervical intraepithelial neoplasia on fertility and early pregnancy outcomes.

DESIGN

Systematic review and meta-analysis of cohort studies.

DATA SOURCES

Medline and Embase.

ELIGIBILITY CRITERIA

Studies assessing fertility and early pregnancy outcomes in women with a history of treatment for cervical intraepithelial neoplasia versus untreated women. We classified the included studies according to treatment type and fertility or early pregnancy endpoint.

ANALYSIS

Pooled relative risks and 95% confidence intervals using a random effect model, and interstudy heterogeneity with I(2) statistics.

RESULTS

15 studies fulfilled the inclusion criteria and were included. The meta-analysis did not provide any evidence that treatment for cervical intraepithelial neoplasia adversely affected the chances of conception. The overall pregnancy rate was higher for treated women than for untreated women (four studies; 43% v 38%, pooled relative risk 1.29, 95% confidence interval 1.02 to 1.64), although the heterogeneity between studies was high (P<0.0001). Pregnancy rates did not differ between women with an intention to conceive (two studies; 88% v 95%, 0.93, 0.80 to 1.08) and the number requiring more than 12 months to conceive (three studies, 15% v 9%, 1.45, 0.89 to 2.37). Although the rates for total miscarriages (10 studies; 4.6% v 2.8%, 1.04, 0.90 to 1.21) and miscarriage in the first trimester (four studies; 9.8% v 8.4%, 1.16, 0.80 to 1.69) was similar for treated and untreated women, cervical treatment was associated with a significantly increased risk of miscarriage in the second trimester. The rate was higher for treated women than for untreated women (eight studies; 1.6% v 0.4%, 16,558 women; 2.60, 1.45 to 4.67). The number of ectopic pregnancies (1.6% v 0.8%; 1.89, 1.50 to 2.39) and terminations (12.2% v 7.4%; 1.71, 1.31 to 2.22) was also higher for treated women.

CONCLUSION

There is no evidence suggesting that treatment for cervical intraepithelial neoplasia adversely affects fertility, although treatment was associated with a significantly increased risk of miscarriages in the second trimester. Research should explore mechanisms that may explain this increase in risk and stratify the impact that treatment may have on fertility and early pregnancy outcomes by the size of excision and treatment method used.

MTHFR C677T polymorphism was an ethnicity-dependent risk factor for cervical cancer development: evidence based on a meta-analysis

INTRODUCTION

Many studies have studied the associations between 5, 10-methylene tetrahydrofolate reductase (MTHFR) polymorphisms and susceptibilities of cervical cancer and cervical intraepithelial neoplasia (CIN); however, the results were inconsistent. The aim of this study was to further assess the relationships by the method of meta-analysis.

MATERIALS AND METHODS

Two investigators independently searched the PubMed, Embase, Wang Fang (Chinese database) and CNKI (China National Knowledge Infrastructure), with latest update to July 1st, 2011. The pooled odds ratio (OR) and 95 % confidence interval (95 % CI) were used to assess the strength of the associations by using fixed- or random-effect model.

RESULTS

Ten case-control studies were included in this meta-analysis including a total of 1,803 cervical cancer or CIN cases and 2,363 controls. Pooled analyses showed that T allele of MTHFR C677T was significantly associated with increased CIN risk [OR (95 % CI): 1.28 (1.03-1.50) for CT vs. CC], especially for low-grade CIN risk. In addition, MTHFR C677T rather than A1298C polymorphism was associated with risk of cervical cancer. Stratifying analyses for ethnicity indicated that T allele of MTHFR C677T was associated with increased cervical cancer risk for Asian [OR (95 % CI): 1.56 (1.17-2.08) for TT vs. CC; 1.53 (1.19-1.96) for TT vs. C carriers] while decreased risk for Caucasian [OR (95 % CI): 0.63 (0.45-0.89) for TT vs. CC; 0.66 (0.56-0.79) for T carriers vs. CC].

CONCLUSION

This meta-analysis suggested that there was no association between MTHFR A1298C polymorphism and cervical cancer risk. However, MTHFR C677T was an ethnicity-dependent risk factor for cervical cancer occurrence. In addition, T allele of C677T was significantly associated with risk of low grade of CIN incidence. Because of modest limitations of our study, well-designed studies with large sample size were needed to confirm our findings in the future.