Castanon A, Landy R, Brocklehurst P, Evans H, Singh N, Walker P, Peebles D, Patnick J, Sasieni P for the PaCT Study Group

Wolfson Institute of Preventive Medicine

Sadler, JAMA 2004

Women attending colp 426 Not treated 652 Treated

RR 1.1 (0.8-1.5) overall RR 3.6 (1.8-7.5) depth ≥17mm

Kyrgiou, Lancet 2006

8 studies 3 studies

RR 1.70 (1.24-2.35) overall RR 2.61 (1.285-5.34 ) depth >10mm

Albrechtsen, BMJ 2008

15,108 births post-colp, 17.2% preterm 57,136 births pre-colp, 6.7% preterm

RR 4.4 (3.8-5.0) 24-27 weeks RR 2.5 (2.4-2.6) 33-36 weeks

Bruinsma, BJOG 2011

6 Studies

7 studies

RR 1.25 (0.98-1.58), Punch vs. treated RR 1.96 (1.46-2.64), Post vs. pre treatment

Studies using UK data suggested a weaker association.

In England colposcopy and treatment of CIN is quality assured

St Mary's

Royal Cornwall

Whipps Cross

The James Cook

St James's University Hospital Royal Preston Hospital

Wirral University Hospital Royal Hallamshire Hospital

Hammersmith

Royal Devon and Exeter

Barts & London

North Durham County and Darlington

Worcestershire Acute

Participating Hospitals

Colposcopy data: 1987-2009

NHS number

Date of birth

Hospital Episode Statistics

Obstetric data: 1998-2009

Wolfson Institute

Obstetric and

Colposcopy data

To explore the association between treatment at colposcopy and preterm delivery

Outcomes:

Preterm rates in England compared to those in women attending colposcopy

*Castanon et al (BMJ 2012)

The average preterm delivery rate in England between 2000-2012 was 6.7% (95% CI 6.6-6.8)

Out of 18,450 singleton births in our cohort 8.8% (95% CI 8.3-9.2) were preterm

The difference between these proportions is 2.1% (95% CI 1.7%-2.5%; p<0.0001)

Women attending colposcopy were 31% more likely to have a preterm birth than the general population (RR 1.31, 95% CI 1.25-1.37)

*Castanon et al (BMJ 2012)

Overall for the study

St Mary's Hospital, Imperial College

Royal Cornwall Hospital

Whipps Cross University Hospital

The James Cook University Hospital

Study Centre

St James's University Hospital

Royal Preston Hospital

Wirral University Teaching Hospital

Royal Hallamshire Hospital

Hammersmith Hospital, Imperial College

Royal Devon and Exeter NHS Foundation Trust

Barts and the London NHS Trust

North Durham County and Darlington Trust

8.8 (8.4, 9.2)

Proportion preterm (95% CI)

16.7 (11.8, 21.6)

8.8 (7.5, 10.1)

8.7 (7.6, 9.9)

10.4 (8.8, 12.0)

10.2 (8.5, 11.9)

7.8 (6.5, 9.2)

6.0 (5.2, 6.9)

10.1 (8.8, 11.5)

7.7 (6.3, 9.2)

8.9 (7.4, 10.3)

10.7 (9.3, 12.0)

6.2 (3.8, 8.6)

England 6.7 (6.62, 6.76)

Preterm births were more common among women attending colposcopy before birth (8.9%) than after birth (7.5%)

*Castanon et al (BMJ 2012)

Women treated at colposcopy were at increased risk compared to those with a punch only. This was true both for births after colposcopy and for births before colposcopy!

Birth after colposcopy

Adjusted RR Cone:Punch

1.19 (1.01-1.41) 1.31 (0.97-1.76)

*Castanon et al (BMJ 2012)

Women treated at colposcopy were at increased risk compared to those with a punch only. This was true both for births after colposcopy and for births before colposcopy!

Birth after colposcopy Birth before colposcopy

Adjusted RR After:Before colposcopy

Adjusted RR Cone:Punch

1.19 (1.01-1.41) 1.31 (0.97-1.76) 0.91 (0.66-1.26)

*Castanon et al (BMJ 2012)

Similarly, women giving birth post colposcopy were at increased risk compared to those giving birth before colposcopy. This was true even if they only had a punch biopsy at colposcopy!

LLETZ

Adjusted RR Post:Pre-colposcopy

1.33 (1.04-1.70) 1.45 (1.15-1.83)

*Castanon et al (BMJ 2012)

Similarly, women giving birth post colposcopy were at increased risk compared to those giving birth before colposcopy. This was true even if they only had a punch biopsy at colposcopy!

LLETZ Punch biopsy Adjusted RR After:Before colposcopy

Adjusted RR Post:Pre-colposcopy

1.33 (1.04-1.70) 1.45 (1.15-1.83) 0.91 (0.66-1.26)

*Castanon et al (BMJ 2012)

• The risk of preterm birth in England is substantially (and significantly) less than that found in most other studies predominantly from Nordic countries

• All aspects of colposcopy are quality managed in the UK

The increased risk in those attending colposcopy may be due to confounding and not caused by treatment

Co-authors Landy R and Castanon A– Centre for Cancer Prevention QMUL Brocklehurst P and Peebles D - Institute for Women's Health UCL Walker P, Evans H - Department of Gynaecology, Royal Free Hampstead NHS Trust Singh N - Division of Cellular Pathology, Barts and the London NHS Trust Patnick J - NHS Cancer Screening Programmes The PaCT Study Group Singh N and Parberry A (Barts Health NHS Trust); Ghaem-Maghami S and Soutter P (Royal Hammersmith Hospital); Lyons D (St Mary’s Hospital, Imperial College); Lincoln K and Rolland P (The James Cook University Hospital); Wood N and Preston S (Royal Preston Hospital); Senguita P and Dent J (North Durham County and Darlington Trust); Das N and Russ L (Royal Cornwall Hospital); Hannemann M and Fuller D (Royal Devon and Exeter NHS Foundation Trust); Palmer J(Royal Hallamshire Hospital); Hutson R (St James University Hospital); Hollingworth A and Wuntakal (Whipps Cross University Hospital); Gul N and Miles A (Wirral University Teaching Hospital); China S and Raghavan R (Worcestershire Acute Hospital NHS Trust)

These slides present independent research funded by the National Institute for Health Research (NIHR) under its Research for Patient

Benefit (RfPB) Programme (Grant Reference Number PB-PG-1208-16187). The views expressed are those of the author(s) and not

necessarily those of the NHS, the NIHR or the Department of Health.