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. 2017 Nov 2;11(11):CD012847.
doi: 10.1002/14651858.CD012847.

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

Maria Kyrgiou  1 , Antonios Athanasiou, Ilkka E J Kalliala, Maria Paraskevaidi, Anita Mitra, Pierre Pl Martin-Hirsch, Marc Arbyn, Phillip Bennett, Evangelos Paraskevaidis
Affiliations

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

Maria Kyrgiou et al. Cochrane Database Syst Rev. .

Abstract

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 In an attempt to identify articles missed by the search or unpublished data, we contacted experts in the field and we handsearched the references of the retrieved articles and conference proceedings.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.

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Conflict of interest statement

No known conflict of interest for the published work. Details are included in the individual conflict of interest forms completed by each author.

Figures

1
1
Flow diagram.
2
2
'Risk of bias' graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
3
3
'Risk of bias' summary: review authors' judgements about each risk of bias item for each included study.
1.1
1.1. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 1 PTB (<37w).
1.2
1.2. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 2 PTB (<37w)‐Analysis by treatment modality.
1.3
1.3. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 3 PTB (<32‐34w).
1.4
1.4. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 4 PTB (<32‐34w)‐Analysis by treatment modality.
1.5
1.5. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 5 PTB (<28‐30w).
1.6
1.6. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 6 PTB (<28‐30w)‐Analysis by treatment modality.
1.7
1.7. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 7 PTB (≤34w).
1.8
1.8. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 8 PTB (≤34w)‐Analysis by treatment modality.
1.9
1.9. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 9 PTB (<32‐33w).
1.10
1.10. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 10 PTB (<32‐33w)‐Analysis by treatment modality.
1.11
1.11. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 11 PTB (<30w).
1.12
1.12. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 12 PTB (<30w)‐Analysis by treatment modality.
1.13
1.13. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 13 PTB (<28w).
1.14
1.14. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 14 PTB (<28w)‐Analysis by treatment modality.
1.15
1.15. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 15 PTB (<37w)‐Nulliparous women.
1.16
1.16. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 16 PTB (<37w)‐Parous women.
1.17
1.17. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 17 PTB (<37w)‐Single cone.
1.18
1.18. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 18 PTB (<37w)‐Repeat cones.
1.19
1.19. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 19 PTB (<37w)‐Singleton pregnancies.
1.20
1.20. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 20 PTB (<37w)‐Multiple pregnancies.
1.21
1.21. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 21 PTB (<32‐34w)‐Multiple pregnancies.
1.22
1.22. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 22 PTB (<28w)‐Multiple pregnancies.
1.23
1.23. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 23 PTB (<37w)‐Depth≤10‐12mm.
1.24
1.24. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 24 PTB (<37w)‐Depth≥10‐12mm.
1.25
1.25. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 25 PTB (<37w)‐Depth≥15‐17mm.
1.26
1.26. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 26 PTB (<37w)‐Depth≥20mm.
1.27
1.27. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 27 PTB (<37w)‐Volume<6cc.
1.28
1.28. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 28 PTB (<37w)‐Volume>6cc.
1.29
1.29. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 29 PTB (<37w)‐Depth≤10mm.
1.30
1.30. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 30 PTB (<37w)‐Depth≤12mm.
1.31
1.31. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 31 PTB (<37w)‐Depth≤15mm.
1.32
1.32. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 32 PTB (<37w)‐Depth≤17mm.
1.33
1.33. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 33 PTB (<37w)‐Depth≤15‐17mm.
1.34
1.34. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 34 PTB (<37w)‐Depth≤20mm.
1.35
1.35. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 35 PTB (<37w)‐Depth≥10mm.
1.36
1.36. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 36 PTB (<37w)‐Depth≥12mm.
1.37
1.37. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 37 PTB (<37w)‐Depth≥15mm.
1.38
1.38. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 38 PTB (<37w)‐Depth≥17mm.
1.39
1.39. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 39 PTB (<37w)‐Depth 10/13‐15/16mm.
1.40
1.40. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 40 PTB (<37w)‐Depth 15/16‐19/20mm.
1.41
1.41. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 41 PTB (<37w)‐Volume<3cc.
1.42
1.42. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 42 PTB (<37w)‐Volume>3cc.
1.43
1.43. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 43 PTB (<37w)‐Depth≥10‐12mm vs ≤10‐12mm.
1.44
1.44. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 44 PTB (<37w)‐Depth≥15‐17mm vs ≤15‐17mm.
1.45
1.45. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 45 PTB (<37w)‐Depth≥20mm vs ≤20mm.
1.46
1.46. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 46 PTB (<37w)‐Volume>3cc vs <3cc.
1.47
1.47. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 47 PTB (<37w)‐Volume>6cc vs <6cc.
1.48
1.48. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 48 PTB (<37w)‐Depth 11/13‐15/16mm vs ≤10‐12mm.
1.49
1.49. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 49 PTB (<37w)‐Depth 16‐19mm vs 13‐15mm.
1.50
1.50. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 50 PTB (<37w)‐Depth≥20mm vs 15/16‐19/20mm.
1.51
1.51. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 51 PTB (<37w)‐Untreated External Comparison Group.
1.52
1.52. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 52 PTB (<37w)‐Untreated Internal Comparison Group (self‐matching).
1.53
1.53. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 53 PTB (<37w)‐Untreated Internal Comparison Group (pre‐treatment pregnancies).
1.54
1.54. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 54 PTB (<37w)‐Untreated Colposcopy+/‐CIN+/‐Biopsy Comparison Group.
1.55
1.55. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 55 PTB (<37w)‐Untreated HSIL Comparison Group.
1.56
1.56. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 56 PTB (<37w)‐All Comparison Groups.
1.57
1.57. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 57 PTB (<37w)‐Untreated High‐risk Population vs General Population.
1.58
1.58. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 58 PTB (<37w)‐Depth≤10‐12mm vs Untreated External Comparison Group.
1.59
1.59. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 59 PTB (<37w)‐Depth≤10‐12mm vs Untreated Internal Comparison Group.
1.60
1.60. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 60 PTB (<37w)‐Depth≤10‐12mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.61
1.61. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 61 PTB (<37w)‐Depth≤15‐17mm vs Untreated External Comparison Group.
1.62
1.62. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 62 PTB (<37w)‐Depth≤15‐17mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.63
1.63. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 63 PTB (<37w)‐Depth≤20mm vs Untreated External Comparison Group.
1.64
1.64. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 64 PTB (<37w)‐Depth≤20mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.65
1.65. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 65 PTB (<37w)‐Depth≥10‐12mm vs Untreated External Comparison Group.
1.66
1.66. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 66 PTB (<37w)‐Depth≥10‐12mm vs Untreated Internal Comparison Group.
1.67
1.67. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 67 PTB (<37w)‐Depth≥10‐12mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.68
1.68. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 68 PTB (<37w)‐Depth≥15‐17mm vs Untreated External Comparison Group.
1.69
1.69. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 69 PTB (<37w)‐Depth≥15‐17mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.70
1.70. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 70 PTB (<37w)‐Depth≥20mm vs Untreated External Comparison Group.
1.71
1.71. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 71 PTB (<37w)‐Depth≥20mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.72
1.72. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 72 PTB (<37w)‐Depth 10/13‐15/16mm vs Untreated External Comparison Group.
1.73
1.73. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 73 PTB (<37w)‐Depth 10/13‐15/16mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
1.74
1.74. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 74 PTB (<37w)‐Depth 15/16‐19/20mm vs Untreated External Comparison Group.
1.75
1.75. Analysis
Comparison 1 Maternal Outcomes‐PTB, Outcome 75 PTB (<37w)‐Depth 15/16‐19/20mm vs Untreated Colposcopy+/‐CIN+/‐Biopsy.
2.1
2.1. Analysis
Comparison 2 Other maternal Outcomes, Outcome 1 sPTB (<37w).
2.2
2.2. Analysis
Comparison 2 Other maternal Outcomes, Outcome 2 sPTB (<32‐34w).
2.3
2.3. Analysis
Comparison 2 Other maternal Outcomes, Outcome 3 sPTB (<28w).
2.4
2.4. Analysis
Comparison 2 Other maternal Outcomes, Outcome 4 pPROM (<37w).
2.5
2.5. Analysis
Comparison 2 Other maternal Outcomes, Outcome 5 pPROM (<32w).
2.6
2.6. Analysis
Comparison 2 Other maternal Outcomes, Outcome 6 pPROM (<28w).
2.7
2.7. Analysis
Comparison 2 Other maternal Outcomes, Outcome 7 Threatened PTB.
2.8
2.8. Analysis
Comparison 2 Other maternal Outcomes, Outcome 8 Chorioamnionitis.
2.9
2.9. Analysis
Comparison 2 Other maternal Outcomes, Outcome 9 Caeserean Section.
2.10
2.10. Analysis
Comparison 2 Other maternal Outcomes, Outcome 10 Instrumental Deliveries (ventouse/forceps).
2.11
2.11. Analysis
Comparison 2 Other maternal Outcomes, Outcome 11 Precipitous Labour (<2hours).
2.12
2.12. Analysis
Comparison 2 Other maternal Outcomes, Outcome 12 Prolonged labour (>12hours).
2.13
2.13. Analysis
Comparison 2 Other maternal Outcomes, Outcome 13 Induction of Labour.
2.14
2.14. Analysis
Comparison 2 Other maternal Outcomes, Outcome 14 Oxytocin Use.
2.15
2.15. Analysis
Comparison 2 Other maternal Outcomes, Outcome 15 Epidural Use.
2.16
2.16. Analysis
Comparison 2 Other maternal Outcomes, Outcome 16 Pethidine Use.
2.17
2.17. Analysis
Comparison 2 Other maternal Outcomes, Outcome 17 Analgesia Use NOS.
2.18
2.18. Analysis
Comparison 2 Other maternal Outcomes, Outcome 18 Cervical stenosis.
2.19
2.19. Analysis
Comparison 2 Other maternal Outcomes, Outcome 19 Antepartum Haemorrhage.
2.20
2.20. Analysis
Comparison 2 Other maternal Outcomes, Outcome 20 Postpartum Haemorrhage (>600ml).
2.21
2.21. Analysis
Comparison 2 Other maternal Outcomes, Outcome 21 Massive Obstetric Haemorrhage (>1000ml).
2.22
2.22. Analysis
Comparison 2 Other maternal Outcomes, Outcome 22 Cervical cerclage.
3.1
3.1. Analysis
Comparison 3 Neonatal Outcomes, Outcome 1 LBW (<2500g).
3.2
3.2. Analysis
Comparison 3 Neonatal Outcomes, Outcome 2 LBW (<2000g).
3.3
3.3. Analysis
Comparison 3 Neonatal Outcomes, Outcome 3 LBW (<1500g).
3.4
3.4. Analysis
Comparison 3 Neonatal Outcomes, Outcome 4 LBW (<1000g).
3.5
3.5. Analysis
Comparison 3 Neonatal Outcomes, Outcome 5 NICU Admission.
3.6
3.6. Analysis
Comparison 3 Neonatal Outcomes, Outcome 6 Perinatal Mortality.
3.7
3.7. Analysis
Comparison 3 Neonatal Outcomes, Outcome 7 Perinatal Mortality (<37w).
3.8
3.8. Analysis
Comparison 3 Neonatal Outcomes, Outcome 8 Perinatal Mortality (<32w).
3.9
3.9. Analysis
Comparison 3 Neonatal Outcomes, Outcome 9 Perinatal Mortality (<28w).
3.10
3.10. Analysis
Comparison 3 Neonatal Outcomes, Outcome 10 Stillbirth.
3.11
3.11. Analysis
Comparison 3 Neonatal Outcomes, Outcome 11 Apgar score (≤5)(1min).
3.12
3.12. Analysis
Comparison 3 Neonatal Outcomes, Outcome 12 Apgar score (<7)(1min).
3.13
3.13. Analysis
Comparison 3 Neonatal Outcomes, Outcome 13 Apgar score (<7)(5min).
See this image and copyright information in PMC

References

References to studies included in this review

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Heinonen 2013 {published data only}
    1. Heinonen A, Gissler M, Riska A, Paavonen J, Tapper AM, Jakobsson M. Loop electrosurgical excision procedure and the risk for preterm delivery. Obstetrics and Gynecology 2013;121(5):1063‐8. - PubMed
Hemmingsson 1982 {published data only}
    1. Hemmingsson E. Outcome of third trimester pregnancies after cryotherapy of the uterine cervix. British Journal of Obstetrics and Gynaecology 1982;89(8):675‐7. - PubMed
Himes 2007 {published data only}
    1. Himes KP, Simhan HN. Time from cervical conization to pregnancy and preterm birth. Obstetrics and Gynecology 2007;109(2 Pt 1):314‐9. - PubMed
Jakobsson 2007 {published data only}
    1. Jakobsson M, Gissler M, Sainio S, Paavonen J, Tapper AM. Preterm delivery after surgical treatment for cervical intraepithelial neoplasia. Obstetrics and Gynecology 2007;109(2 Pt 1):309‐13. - PubMed
Jakobsson 2009 {published data only}
    1. Jakobsson M, Gissler M, Paavonen J, Tapper AM. Loop electrosurgical excision procedure and the risk for preterm birth. Obstetrics and Gynecology 2009;114(3):504‐10. - PubMed
Jones 1979 {published data only}
    1. Jones JM, Sweetnam P, Hibbard BM. The outcome of pregnancy after cone biopsy of the cervix: a case‐control study. British Journal of Obstetrics and Gynaecology 1979;86(12):913‐6. - PubMed
Kirn 2015 {published data only}
    1. Kirn V, Geiger P, Riedel C, Bergauer F, Friese K, Kainer F, Knabl J. Cervical conisation and the risk of preterm delivery: a retrospective matched pair analysis of a German cohort. Archives of Gynecology and Obstetrics 2015;291(3):599‐603. - PubMed
Kitson 2014 {published data only}
    1. Kitson SJ, Greig E, Michael E, Smith M. Predictive value of volume of cervical tissue removed during LLETZ on subsequent preterm delivery: a cohort study. European Journal of Obstetrics and Gynecology and Reproductive Biology 2014;180:51‐5. - PubMed
Klaritsch 2006 {published data only}
    1. Klaritsch P, Reich O, Giuliani A, Tamussino K, Haas J, Winter R. Delivery outcome after cold‐knife conization of the uterine cervix. Obstetrics and Gynecology 2006;103(2):604‐7. - PubMed
Kristensen 1985 {published data only}
    1. Kristensen GB. The outcome of pregnancy and preterm delivery after conization of the cervix. Archives of Gynecology 1985;236(3):127‐30. - PubMed
Kristensen 1993 {published data only}
    1. Kristensen J, Langhoff‐Ross J, Kristensen FB. Increased risk of preterm birth in women with cervical conization. Obstetrics and Gynecology 1993;81(6):1005‐8. - PubMed
Kuoppala 1986 {published data only}
    1. Kuoppala T, Saarikoski S. Pregnancy and delivery after cone biopsy of the cervix. Archives of Gynecology 1986;237(3):149‐54. - PubMed
Larsson 1982 {published data only}
    1. Larsson G, Grundsell H, Gullberg B, Svennerud S. Outcome of pregnancy after conization. Acta Obstetricia et Gynecologica Scandinavica 1982;61(5):461‐6. - PubMed
Lima 2011 {published data only}
    1. Lima AF, Francisco C, Julio C, Paula T, Vitorino A, Borrego J. Obstetric outcomes after treatment for cervical intraepithelial neoplasia: six years of experience. Journal of Lower Genital Tract Disease 2011;15(14):276‐9. - PubMed
Ludviksson 1982 {published data only}
    1. Ludviksson K, Sandstrom B. Outcome of pregnancy after cone biopsy‐‐a case‐control study. European Journal of Obstetrics and Gynecology and Reproductive Biology 1982;14(3):135‐42. - PubMed
Martyn 2015 {published data only}
    1. Martyn FM, McAuliffe FM, Beggan C, Downey P, Flannelly G, Wingfield MB. Excisional treatments of the cervix and effect on subsequent fertility: a retrospective cohort study. European Journal of Obstetrics and Gynecology and Reproductive Biology 2015;185:114‐20. - PubMed
Miller 2015 {published data only}
    1. Miller ES, Sakowicz A, Grobman, WA. The association between cervical dysplasia, a short cervix, and preterm birth. American Journal of Obstetrics and Gynecology 2015;213:543 e1‐4. - PubMed
Moinian 1982 {published data only}
    1. Moinian M, Andersch B. Does cervix conization increase the risk of complications in subsequent pregnancies?. Acta Obstetricia et Gynecologica Scandinavica 1982;61(2):101‐3. - PubMed
Noehr 2009a {published data only}
    1. Noehr B, Jensen A, Frederiksen K, Tabor A, Kjaer SK. Depth of cervical cone removed by loop electrosurgical excision procedure and subsequent risk of spontaneous preterm delivery. Obstetrics and Gynecology 2009;114(6):1232‐8. - PubMed
    1. Noehr B, Jensen A, Frederiksen K, Tabor A, Kjaer SK. Loop electrosurgical excision of the cervix and subsequent risk for spontaneous preterm delivery: a population‐based study of singleton deliveries during a 9‐year period. American Journal of Obstetrics and Gynecology 2009;201(1):33.e1‐6. - PubMed
    1. Nohr B, Tabor A, Frederiksen K, Kjaer SK. Loop electrosurgical excision of the cervix and the subsequent risk of preterm delivery. Acta Obstetricia et Gynecologica Scandinavica 2007;86(5):596‐603. - PubMed
Noehr 2009b {published data only}
    1. Noehr B, Jensen A, Frederiksen K, Tabor A, Kjaer SK. Loop electrosurgical excision of the cervix and risk for spontaneous preterm delivery in twin pregnancies. Obstetrics and Gynecology 2009;114(3):511‐5. - PubMed
Ortoft 2010 {published data only}
    1. Ortoft G, Henriksen T, Hansen E, Petersen L. After conisation of the cervix, the perinatal mortality as a result of preterm delivery increases in subsequent pregnancy. BJOG: an international journal of obstetrics and gynaecology 2010;117(3):258‐67. - PubMed
Paraskevaidis 2002 {published data only}
    1. Paraskevaidis E, Koliopoulos G, Lolis E, Papanikou E, Malamou‐Mitsi V, Agnantis NJ. Delivery outcomes following loop electrosurgical excision procedure for micro‐invasive (FIGO stage IA1) cervical cancer. Gynecologic Oncology 2002;86(1):10‐3. - PubMed
Parikh 2008 {published data only}
    1. Parikh R, Horne H, Feinstein SJ, Anasti JN. Cervical length screening in patients who have undergone loop electrosurgical excision procedure. Journal of Reporoductive Medicine 2008;53(12):909‐13. - PubMed
Poon 2012 {published data only}
    1. Poon LC, Savvas M, Zamblera D, Skyfta E, Nicolaides KH. Large loop excision of transformation zone and cervical length in the prediction of spontaneous preterm delivery. BGOJ: an international journal of obstetrics and gynaecology 2012;119(6):692‐8. - PubMed
Raio 1997 {published data only}
    1. Raio L, Ghezzi F, Naro E, Gomez R, Luscher KP. Duration of pregnancy after carbon dioxide laser conization of the cervix: influence of cone height. Obstetrics and Gynecology 1997;90(6):978‐82. - PubMed
Reilly 2012 {published data only}
    1. Reilly R, Paranjothy S, Beer H, Brooks CJ, Fielder HM, Lyons RA. Birth outcomes following treatment for precancerous changes to the cervix: a population‐based record linkage study. BJOG: an international journal of obstetrics and gynaecology 2012;119(2):236‐44. - PubMed
Sadler 2004 {published data only}
    1. Sadler L, Saftlas A, Wang W, Exeter M, Whittaker J, McCowan L. Treatment for cervical intraepithelial neoplasia and risk of preterm delivery. JAMA 2004;291(17):2100‐6. - PubMed
Sagot 1995 {published data only}
    1. Sagot P, Caroit Y, Winer N, Lopes P, Boog G. Obstetrical prognosis for carbon dioxide laser conisation of the uterine cervix. European Journal of Obstetrics and Gynecology and Reproductive Biology 1995;58(1):53‐8. - PubMed
Samson 2005 {published data only}
    1. Samson SL, Bentley JR, Fahey TJ, McKay DJ, Gill GH. The effect of loop electrosurgical excision procedure on future pregnancy outcome. Obstetrics and Gynecology 2005;105(2):325‐32. - PubMed
Saunders 1986 {published data only}
    1. Saunders N, Fenton DW, Soutter WP, Brown VA, Sharp F, Abernethy F. A case controlled study of the outcome of pregnancy following laser vaporization cone of the cervix. In: Sharp F, Jordan JA editor(s). Gynaecological Laser surgery: Proceedings of the Fifteenth Study Group of the Royal College of Obstetricians and Gynaecologists. Reproductive and Perinatal Medicine (VI). Ithaca, New York: Perinatology Press, 1986:121‐5.
Shanbhag 2009 {published data only}
    1. Shanbhag S, Clark H, Timmaraju V, Bhattacharya S, Cruickshank M. Pregnancy outcome after treatment for cervical intraepithelial neoplasia. Obstetrics and Gynecology 2009;114(4):727‐35. - PubMed
Simoens 2012 {published data only}
    1. Simoens C, Goffin F, Simon P, Barlow P, Antoine J, Foidart JM, et al. Adverse obstetrical outcomes after treatment of precancerous cervical lesions: a Belgian multicentre study. BJOG: an international journal of obstetrics and gynaecology 2012;119(10):1247‐55. - PubMed
Sjoborg 2007 {published data only}
    1. Sjoborg KD, Vistad I, Myhr SS, Svenningsen R, Herzog C, Kloster‐Jensen A, et al. Pregnancy outcome after cervical cone excision: a case‐control study. Acta Obstetricia et Gynecologica Scandinavica 2007;86(4):423‐8. - PubMed
Sozen 2014 {published data only}
    1. Sozen H, Namazov A, Cakir S, Akdemir Y, Vatansever D, Karateke A. Pregnancy outcomes after cold knife conization related to excised cone dimensions. A retrospective cohort study. Journal of Reporoductive Medicine 2014;59(1‐2):81‐6. - PubMed
Spitzer 1995 {published data only}
    1. Spitzer M, Herman J, Krumholz BA, Lesser M. The fertility of women after laser cervical conisation. Obstetrics and Gynecology 1995;86(4 Pt 1):504‐8. - PubMed
Stout 2015 {published data only}
    1. Stout MJ, Frey HA, Tuuli MG, Cahill AG, Odibo AO, Roehl KA, et al. Loop electrosurgical excision procedure and risk of vaginal infections during pregnancy: an observational study. BJOG : an international journal of obstetrics and gynaecology 2015;122(4):545‐51. - PMC - PubMed
Tan 2004 {published data only}
    1. Tan L, Pepra E, Haloob RK. The outcome of pregnancy after large loop excision of the transformation zone of the cervix. Journal of Obstetrics and Gynaecology 2004;24(1):25‐7. - PubMed
Turlington 1996 {published data only}
    1. Turlington WT, Wright BD, Powell JL. Impact of the loop electrosurgical excision procedure on future fertility. Journal of Reporoductive Medicine 1996;41(11):815‐8. - PubMed
van de Vijner 2010 {published data only}
    1. Vijver A, Poppe W, Verguts J, Arbyn M. Pregnancy outcome after cervical conisation: a retrospective cohort study in the Leuven University Hospital. BJOG: an international journal of obstetrics and gynaecology 2010;117(3):268‐73. - PubMed
Van Hentenryck 2012 {published data only}
    1. Hentenryck M, Noel JC, Simon P. Obstetric and neonatal outcome after surgical treatment of cervical dysplasia. European Journal of Obstetrics and Gynecology and Reproductive Biology 2012;162(1):16‐20. - PubMed
van Rooijen 1999 {published data only}
    1. Rooijen M, Persson E. Pregnancy outcome after laser vaporization of the cervix. Acta Obstetricia et Gynecologica Scandinavica 1999;78(4):346‐8. - PubMed
Weber 1979 {published data only}
    1. Weber T, Obel EB. Pregnancy complications following conization of the uterine cervix (II). Acta Obstetricia et Gynecologica Scandinavica 1979;58(4):347‐51. - PubMed
Werner 2010 {published data only}
    1. Werner CL, Lo JY, Heffernan T, Griffith WF, McIntire DD, Leveno KJ. Loop electrosurgical excision procedure and risk of preterm birth. Obstetrics and Gynecology 2010;115(3):605‐8. - PubMed
Wuntakal 2013 {published data only}
    1. Wuntakal R, Castanon A, Sasieni PD, Hollingworth A. Pregnancy outcomes after treatment for cervical intraepithelial neoplasia in a single NHS hospital. International Journal of Gynecological Cancer 2013;23(4):710‐5. - PubMed

References to studies excluded from this review

Al‐Halal 2013 {published data only}
    1. Al‐Halal H, Kezouh A, Abenhaim HA. Incidence and obstetrical outcomes of cervical intraepithelial neoplasia and cervical cancer in pregnancy: a population‐based study on 8.8 million births. Archives of Gynecology and Obstetrics 2013;287(2):245‐50. - PubMed
Althuisius 2001 {published data only}
    1. Althuisius SM, Schornagel IJ, Dekker GA, Geijn HP, Hummel P. Loop electrosurgical excision procedure of the cervix and time of delivery in subsequent pregnancy. International Journal of Gynaecology and Obstetrics 2001;72(1):31‐4. - PubMed
Berghella 2004 {published data only}
    1. Berghella V, Pereira L, Gariepy A, Simonazzi G. Prior cone biopsy: prediction of preterm birth by cervical ultrasound. American Journal of Obstetrics and Gynecology 2004;191(4):1393‐7. - PubMed
Berretta 2013 {published data only}
    1. Berretta R, Gizzo S, Dall'Asta A, Mazzone E, Monica M, Franchi L, et al. Risk of preterm delivery associated with prior treatment of cervical precancerous lesion according to the depth of the cone. Disease Markers 2013;35(6):721‐6. - PMC - PubMed
Bull‐Phelps 2007 {published data only}
    1. Bull‐Phelps SL, Garner EI, Walsh CS, Gehrig PA, Miller DS, Schorge JO. Fertility‐sparing surgery in 101 women with adenocarcinoma in situ of the cervix. Gynecologic Oncology 2007;107(2):316‐9. - PubMed
Chevreau 2017 {published data only}
    1. Chevreau J, Mercuzot A, Foulon A, Attencourt C, Sergent F, Lanta S, Gondry J. Impact of age at conization on obstetrical outcome: a case‐control study. Journal of Lower Genital Tract Disease 2017;21(2):97‐101. - PMC - PubMed
Ciavattini 2014 {published data only}
    1. Ciavattini A, Stortoni P, Mancioli F, Puglia D, Tranquilli AL, Liverani CA. The impact of loop electrosurgical excision procedure (LEEP) for CIN 2,3 on spontaneous preterm delivery in twin pregnancies by assisted reproductive technique: preliminary data. Journal of Maternal‐Fetal & Neonatal Medicine 2014;27(11):1169‐71. - PubMed
Ciavattini 2015 {published data only}
    1. Ciavattini A, Clemente N, Delli Carpini G, Gentili C, Giuseppe J, Barbadoro P, et al. Loop electrosurgical excision procedure and risk of miscarriage. Fertility and Sterility 2015;103(4):1043‐8. - PubMed
Conner 2013 {published data only}
    1. Conner SN, Cahill AG, Tuuli MG, Stamilio DM, Odibo AO, Roehl KA, et al. Interval from loop electrosurgical excision procedure to pregnancy and pregnancy outcomes. Obstetrics and Gynecology 2013;122(6):1154‐9. - PMC - PubMed
Ferenczy 1995 {published data only}
    1. Ferenczy A, Choukroun D, Falcone T, Franco E. The effect of cervical loop electrosurgical excision on subsequent pregnancy outcome: North American experience. American Journal of Obstetrics and Gynecology 1995;172(4 Pt 1):1246‐50. - PubMed
Gentry 2000 {published data only}
    1. Gentry DJ, Baggish MS, Brady K, Walsh PM, Hungler MS. The effects of loop excision of the transformation zone on cervical length: implications for pregnancy. American Journal of Obstetrics and Gynecology 2000;182(3):516‐20. - PubMed
Gordon 1991 {published data only}
    1. Gordon HK, Duncan ID. Effective destruction of cervical intraepithelial neoplasia (CIN) 3 at 100 degrees C using the Semm cold coagulator: 14 years experience. British Journal of Obstetrics and Gynaecology 1991;98(1):14‐20. - PubMed
Gronroos 1979 {published data only}
    1. Gronroos M, Liukko P, Kilkku P, Punnonen R. Pregnancy and delivery after conization of the cervix. Acta Obstetricia et Gynecologica Scandinavica 1979;58(5):477‐80. - PubMed
Kalliala 2012 {published data only}
    1. Kalliala I, Anttila A, Dyba T, Hakulinen T, Halttunen M, Nieminen P. Pregnancy incidence and outcome among patients with cervical intraepithelial neoplasia: a retrospective cohort study. BJOG: an international journal of obstetrics and gynaecology 2012;119(2):227‐35. - PubMed
Khalid 2012 {published data only}
    1. Khalid S, Dimitriou E, Conroy R, Paraskevaidis E, Kyrgiou M, Harrity C, et al. The thickness and volume of LLETZ specimens can predict the relative risk of pregnancy‐related morbidity. BJOG: an international journal of obstetrics and gynaecology 2012;119(6):685‐91. - PubMed
Kim 2016 {published data only}
    1. Kim M, Ishioka S, Endo T, Baba T, Saito T. Obstetrical prognosis of patients with cervical intraepithelial neoplasia (CIN) after "coin‐shaped" conization. Archives of Gynecology and Obstetrics 2016;293(3):651‐7. - PubMed
Kindinger 2016 {published data only}
    1. Kindinger L, Kyrgiou M, MacIntyre D, Cacciatore S, Yulia A, Cook J, et al. Preterm birth prevention post‐conization: a model of cervical length screening with targeted cerclage. PLOS One 2016;11(11):e0163793. - PMC - PubMed
Kullander 1971 {published data only}
    1. Kullander S, Sjoberg NO. Treatment of carcinoma in situ of the cervix uteri by conization. A five‐year follow‐up. Acta Obstetricia et Gynecologica Scandinavica 1971;50(2):153‐7. - PubMed
Leiman 1980 {published data only}
    1. Leiman G, Harrison NA, Rubin A. Pregnancy following conization of the cervix: complications related to cone size. American Journal of Obstetrics and Gynecology 1980;136(1):14‐8. - PubMed
Liu 2014 {published data only}
    1. Liu Y, Qiu HF, Tang Y, Chen J, Lv J. Pregnancy outcome after the treatment of loop electrosurgical excision procedure or cold‐knife conization for cervical intraepithelial neoplasia. Gynecological Obstetric Investigation 2014;77(4):240‐4. - PubMed
Liverani 2016 {published data only}
    1. Liverani CA, Giuseppe J, Clemente N, Delli Carpini G, Monti E, Fanetti F, et al. Length but not transverse diameter of the excision specimen for high‐grade cervical intraepithelial neoplasia (CIN 2‐3) is a predictor of pregnancy outcome. European Journal of Cancer Prevention 2016;25(5):416‐22. - PubMed
Macvicar 1968 {published data only}
    1. Macvicar J, Willocks J. The effect of diathermy conization of the cervix on subsequent fertility, pregnancy and delivery. Journal of Obstetrics and Gynaecology of the British Commonwealth 1968;75(3):355‐6. - PubMed
Mariya 2016 {published data only}
    1. Mariya T, Nishikawa A, Sogawa K, Suzuki R, Saito M, Kawamata A, ET AL. Virological and cytological clearance in laser vaporization and conization for cervical intra‐epithelial neoplasia grade 3. Journal of Obstetrics and Gynaecology Research 2016;42:1808‐13. - PubMed
Masamoto 2008 {published data only}
    1. Masamoto H, Nagai Y, Inamine M, Hirakawa M, Okubo E, Ishisoko A, et al. Outcome of pregnancy after laser conization: implications for infection as a causal link with preterm birth. Journal of Obstetrics and Gynaecology Research 2008;34(5):838‐42. - PubMed
Michelin 2009 {published data only}
    1. Michelin MA, Merino LM, Franco CA, Murta EF. Pregnancy outcome after treatment of cervical intraepithelial neoplasia by the loop electrosurgical excision procedure and cold knife conization. Clinical and Experimental Obstetrics & Gynecology 2009;36(1):17‐9. - PubMed
Mitsuhashi 2000 {published data only}
    1. Mitsuhashi A, Sekiya S. Loop electrosurgical excision procedure (LEEP) during first trimester of pregnancy. International Journal of Gynaecology and Obstetrics 2000;71(3):237‐9. - PubMed
Monaghan 1982 {published data only}
    1. Monaghan JM, Kirkup W, Davis JA, Edington PT. Treatment of cervical intraepithelial neoplasia by colposcopically directed cryosurgery and subsequent pregnancy experience. British Journal of Obstetrics and Gynaecology 1982;89(5):387‐92. - PubMed
Naleway 2015 {published data only}
    1. Naleway AL, Weinmann S, Krishnarajah G, Arondekar B, Fernandez J, Swamy G, et al. Pregnancy after treatment for cervical cancer precursor lesions in a retrospective matched cohort. PLOS One 2015;10(2):e0117525. - PMC - PubMed
Nam 2010 {published data only}
    1. Nam KH, Kwon JY, Kim YH, Park YW. Pregnancy outcome after cervical conization: risk factors for preterm delivery and the efficacy of prophylactic cerclage. Journal of Gynecologic Oncology 2010;21(4):225‐9. - PMC - PubMed
Novikova 1994 {published data only}
    1. Novikova EG, Antoshechkina MA. [Reproductive function after the organ‐preserving treatment of early cancerous pathology of the cervix uteri]. Akusherstvo i ginekologiia (Mosk) 1994;2:44‐7. - PubMed
Patrelli 2008 {published data only}
    1. Patrelli TS, Anfuso S, Vandi F, Valitutto S, Migliore M, Salvati MA, et al. Preterm delivery and premature rupture of membranes after conization in 80 women. Preliminary data. Minerva Ginecologica 2008;60(4):295‐8. - PubMed
Pils 2014 {published data only}
    1. Pils S, Eppel W, Seemann R, Natter C, Ott J. Sequential cervical length screening in pregnancies after loop excision of the transformation zone conisation: a retrospective analysis. BJOG : an international journal of obstetrics and gynaecology 2014;121(4):457‐62. - PubMed
Pinborg 2015 {published data only}
    1. Pinborg A, Ortoft G, Loft A, Rasmussen SC, Ingerslev HJ. Cervical conization doubles the risk of preterm and very preterm birth in assisted reproductive technology twin pregnancies. Human Reproduction 2015;30(1):197‐204. - PubMed
Radha Bai Prabhu 2010 {published data only}
    1. Radha Bai Prabhu T. Pregnancy outcome following large loop excision of the transformation zone (LLETZ). Journal of Obstetrics and Gynaecology of India 2010;60(2):149‐51.
Rafaeli‐Yehudai 2014 {published data only}
    1. Rafaeli‐Yehudai T, Kessous R, Aricha‐Tamir B, Sheiner E, Erez O, Meirovitz M, et al. The effect of cervical cerclage on pregnancy outcomes in women following conization. Journal of Maternal‐Fetal & Neonatal Medicine 2014;27(15):1594‐7. - PubMed
Ricciotti 1995 {published data only}
    1. Ricciotti HA, Burke L, Kobelin M, Slomovic B, Ludmir J. Ultrasound evaluation of cervical shortening after loop excision of the transformation zone (LETZ). International Journal of Gynaecology and Obstetrics 1995;50(2):175‐8. - PubMed
Rosen 1991 {published data only}
    1. Rosen A, Klein M, Vavra N, Gitsch G, Karasegh S, Schrock A, et al. [PAP IV in pregnancy‐‐a retrospective multicenter study]. Geburtshilfe Frauenheilkunde 1991;51(3):208‐10. - PubMed
Sangkarat 2014 {published data only}
    1. Sangkarat S, Ruengkhachorn I, Benjapibal M, Laiwejpithaya S, Wongthiraporn W, Rattanachaiyanont M. Long‐term outcomes of a loop electrosurgical excision procedure for cervical intraepithelial neoplasia in a high incidence country. Asian Pacific Journal of Cancer Prevention 2014;15(2):1035‐9. - PubMed
Seki 2010 {published data only}
    1. Seki N, Kodama J, Kusumoto T, Nakamura K, Hongo A, Hiramatsu Y. Complications and obstetric outcomes after laser conization during pregnancy. European Journal of Gynaecological Oncology 2010;31(4):399‐401. - PubMed
Shin 2010 {published data only}
    1. Shin MY, Seo ES, Choi SJ, Oh SY, Kim BG, Bae DS, et al. The role of prophylactic cerclage in preventing pretermdelivery after electrosurgical conization. Journal of Gynecologic Oncology 2010;21(4):230‐6. - PMC - PubMed
Sljivancanin 2013 {published data only}
    1. Sljivancanin D, Kesic V, Tulic L, Dotlic J. [Assessment of the natural course and treatment of premalignant uterine cervical lesions in pregnancy]. Srpski Aarhiv za Celokupno Lekarstvo 2013;141(3‐4):192‐7. - PubMed
Smaldone 2010 {published data only}
    1. Smaldone GM, Krohn MA, McGee EA. Cervical cancer and risk for delivery of small‐for‐gestational age neonates. Journal of Womens Health (Larchmt) 2010;19(5):969‐74. - PubMed
Spracklen 2013 {published data only}
    1. Spracklen CN, Harland KK, Stegmann BJ, Saftlas AF. Cervical surgery for cervical intraepithelial neoplasia and prolonged time to conception of a live birth: a case‐control study. BJOG: an international journal of obstetrics and gynaecology 2013;120(8):960‐5. - PMC - PubMed
Wakita 1990 {published data only}
    1. Wakita K, Izumi T, Kuramoto H, Sasaki N, Shimada N. Pregnancy after laser therapy for the treatment of uterine cervical neoplasia. Journal of Clinical Laser Medicine & Surgery 1990;8(5):71‐6. - PubMed
Watson 2012 {published data only}
    1. Watson LF, Rayner JA, King J, Jolley D, Forster D. Intra‐cervical procedures and the risk of subsequent very preterm birth: a case‐control study. Acta Obstetricia et Gynecologica Scandinavica 2012;91(2):204‐10. - PubMed
Wongtiraporn 2014 {published data only}
    1. Wongtiraporn W, Laiwejpithaya S, Sangkarat S, Benjapibal M, Rattanachaiyanont M, Ruengkhachorn I, et al. Long term outcomes of laser conization for high grade cervical intraepithelial neoplasia in Thai women. Asian Pacific Journal of Cancer Prevention 2014;15(18):7757‐61. - PubMed
Zuo 2011 {published data only}
    1. Zuo Z, Goel S, Carter JE. Association of cervical cytology and HPV DNA status during pregnancy with placental abnormalities and preterm birth. American Journal of Clinical Pathology 2011;136(2):260‐5. - PubMed

References to studies awaiting assessment

Aleman 2016 {published data only}
    1. Aleman JM, Arien F, Tjalma WAA. The impact of conisation on pregnancy outcome. European Journal of Gynaecological Oncology 2016;37:786‐91. - PubMed
Bjorge 2016 {published data only}
    1. Bjorge T, Skare GB, Bjorge L, Trope A, Lonnberg S. Adverse pregnancy outcomes after treatment for cervical intraepithelial neoplasia. Obstetrics and Gynecology 2016;128(6):1265‐73. - PubMed
Brie 2016 {published data only}
    1. Brie C, Turck M, Cheret A, Morello R, Benoist G, Dreyfus M. [Case‐control study of obstetrical outcomes of conisation]. Journal de Gynécologie, Obstétrique et Biologie de la Reproduction [Journal of Gynecology Obstetrics and Human Reproduction] 2016;45(2):192‐7. - PubMed
He 2007 {published data only}
    1. He HJ, Pan LY, Huang HF, Lang JH. [Clinical analysis of the effect of cervical conization on fertility and pregnancy outcome]. Zhonghua Fu Chan Ke Za Zhi 2007;42(8):515‐7. - PubMed
Jancar 2016 {published data only}
    1. Jancar N, Mihevc Ponikvar B, Tomsic S. Cold‐knife conisation and large loop excision of transformation zone significantly increase the risk for spontaneous preterm birth: a population‐based cohort study. European Journal of Obstetrics and Gynecology and Reproductive Biology 2016;203:245‐9. - PubMed
Kalitsaris 1991 {published data only}
    1. Kalitsaris A, Paschopoulos M, Paraskevaidis E, Dalkalitsis N, Tsanadis G, Adonakis G, et al. [Fertility and pregnancy after conization]. Annali di Ostetricia, Ginecologia, Medicina Perinatale 1991;112(4):257‐61. - PubMed
Kasum 1991 {published data only}
    1. Kasum M, Kuvacic I. [Pregnancy outcome after conization]. Jugoslavenska Ginekologija i Perinatologija 1991;31:31‐4. - PubMed
Lund 1986 {published data only}
    1. Lund E, Bjerkedal T. [Cancer in situ of the uterine cervix. Increased perinatal death and prematurity after conization]. Tidsskrift for den Norske Lægeforening 1986;106(7):543‐6. - PubMed
Praest 1979 {published data only}
    1. Praest J. [Conization of the cervix of the uterus]. Ugeskrift For Laeger 1979;51:3509‐11. - PubMed
Spuhler 1995 {published data only}
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References to other published versions of this review

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