Randomised Controlled Trial on the Effect of Copper Impregnated Dressings and Maternity Pads on the Healing of Obstetric Wounds and Wound Infection
Phase: NA
Conditions: Cesarean Section; Infection, Perineal Infection, Wound Infection, Surgical Site Infection
Sponsor: Croydon Health Services NHS Trust

Protocol 
 
 
ECHO study 
The Effect of Copper on the Healing of Obstetric wounds 
VERSION 3 – 17/09/2015 
 
 
 
Authors: 
L.P. Arendsen MD, Research Fellow in Urogynaecology 
R. Thakar MD, FRCOG, Consultant Obstetrician & Gynaecologist, Urogynaecology subspecialist 
A.H. Sultan MD, FRCOG, Consultant Obstetrician & Gynaecologist 
 
Croydon University Hospital 
530 London Road, CR7 7YE  
Croydon, United Kingdom 
Telephone number: 020 8401 3000

Full title: Randomised controlled trial on the effect of copper impregnated dressings and 
maternity pads on the healing of obstetric wounds and wound infection 
 
Background 
In Croydon Health Services around 4,000 babies are born annually and the vast majority are 
born vaginally. The most common complication of vaginal delivery is perineal or vaginal 
laceration with a prevalence as high as 85% and up to 70% will need suturing (1). Within 
Croydon Health Services 73% deliver vaginally of whom 66% sustain perineal laceration 
(19% first degree, 74% second degree, 7% 3rd/4th degree) and an episiotomy is performed in 
24% of the vaginal deliveries. Minor lacerations are often left unsutured, whereas the 
majority of the second or higher degree tears will be sutured directly after delivery. Due to 
supporting factors such as a moist environment and the presence of high numbers of 
bacteria, perineal trauma is associated with wound infection and affects 11% of the women 
with sutured tears (2). Wound infection can cause pain, dehiscence, delayed wound healing 
and interfere with a woman’s ability to nurture their baby and enjoy motherhood (3).  
The caesarean section rate worldwide is rising (4) and the rate in Croydon University 
Hospital is in the region of 25% of all deliveries. The most significant source of maternal 
morbidity after caesarean section is postoperative infection (surgical site infection) and can 
be the cause of a prolonged hospital stay, readmissions (5) sepsis and maternal death (6). 
Surgical site infection is one of the most prevalent reported nosocomial infection, which 
accounts for 14-16% of all hospital-acquired infections. Despite prophylactic antibiotics, the 
rate of wound infection after caesarean section is ranging between 7% and 41% (7-9). 
According to the Centers for Disease Control and Prevention (CDC), surgical site infection 
can be classified as an incisional infection, either superficial or deep, or an organ or space 
infection, such as endometritis (10). See figure one for the CDC surgical site classification. 
 

 
 
The micro-organisms that are most commonly the cause of the infection of perineal tears 
and caesarean section wounds are Enterococci, Streptococci, Staphylococci, Gram-negative 
bacteria and anaerobes (5, 11). As a consequence of antibiotic resistance, MRSA infection 
is becoming an increasing challenge. Several studies have detected MRSA colonisation 
rates of up to 10% in rectovaginal swabs in asymptomatic pregnant women (12, 13). MRSA 
has been proven to cause more severe postpartum infections, especially after caesarean 
section (14-16). Although several strategies to eliminate or reduce colonisation of MRSA 
such as skin wash have been studied, the real efficacy of such interventions remains 
inconclusive (17). Moreover, the preoperative skin preparation using chlorhexidine, which 
reduced the overall rate of surgical site infection, was found ineffective among MRSA 
carriers (18). 
Antimicrobial copper 
The antimicrobial effect of copper has been known for centuries. As early as 2600-2200 BC 
the Egyptians used green copper rust for the treatment of chest wounds and to sterilise 
drinking water. In another Papyrus it was written that copper splinters, shavings and various 

copper salts and oxides were used to treat headaches, burn wounds, itching and skin 
infections (19). With the increase in antibiotic resistant bacteria causing nosocomial 
infections, copper has become a popular subject of recent research. There are many 
laboratory studies showing the biocidal effect of copper on a wide range of microbes such as 
bacteria, fungi and viruses (20, 21). Copper has also been proven to be effective against 
Methicillin-resistant Staphylococcus aureus (MRSA) (22) and Vancomycin-resistant 
Enterococci (VRE) (23). The use of copper surfaces within the hospital setting has been 
evaluated in several clinical studies showing significant reductions in bacterial colonisation 
on copper surfaces compared to standard materials (24). After the use of copper as a 
biocidal contact surface, the use of copper impregnated textiles was explored. Although 
there is a variety of containing copper impregnated textiles available such as socks, 
pyjamas, underwear, bed linen, face masks, stockings and wound dressings, there is a 
paucity of clinical research. There has however been a clinical study on the effect of copper 
impregnated socks in patients suffering from tinea pedis and this revealed a significant 
improvement or resolution of the infection after wearing these socks for two weeks (25). 
 
Wound healing 
Copper is assumed to be involved in several processes crucial for wound healing (26). A key 
role in wound healing is angiogenesis. It has been shown that copper induces the production 
of vascular endothelial growth factor (VEGF) and therefore stimulates angiogenesis (27). 
Furthermore, copper promotes wound healing due to an elevation in integrin expression 
(28); enhancement of fibrinogen stabilisation (29) and up regulation of several enzymes 
essential for matrix remodelling and cell growth (30). Several laboratory studies have 
demonstrated an association between a copper dependant enzyme, lysyl oxidase (LOX), 
and skin ageing and pathological skin conditions (31).  
 
 
 

Safety 
The dermal exposure to copper is considered safe as copper is not only an essential 
element for normal skin function but also essential for the immune system and blood 
coagulation (32). In contrast to microorganisms, human skin cells have the ability to 
metabolise and utilise copper (33) and therefore the development of adverse reactions are 
unlikely.  
 
Our hypothesis is that copper impregnated fibres in maternity pads and surgical wound 
dressings, reduces infection rates in perineal lacerations, episiotomies and caesarean 
section wounds. 
 
Aim 
The aim of this study is to investigate the impact of copper impregnated wound dressings 
and maternity pads on the incidence of infection in perineal wounds after vaginal delivery 
and caesarean section wounds. 
 
Objectives 
Primary:  
1. To assess the effect of copper impregnated wound dressings on the incidence of 
wound infection following caesarean section. 
2. To assess the effect of copper impregnated maternity pads on the incidence of 
wound infection of second degree perineal tears following vaginal delivery. 
 
Secondary:  
1. To assess the effect of copper impregnated wound dressings on other maternal 
outcomes, such as length of hospitalisation, readmission rate and pain of the wound. 
2. To assess the effect of copper impregnated maternity pads on other maternal 
outcomes, such as length of hospitalisation, readmission rate and perineal pain. 

 
Methodology 
This is a double blind randomised controlled pilot study to assess feasibility of copper 
impregnated wound dressings and maternity pads for the healing of obstetric wounds. All 
pregnant women in Croydon University Hospital who attend their routine second-trimester 
scan appointment at approximately 20 weeks of gestation will receive a detailed patient 
information sheet (Appendix 1 Patient Information Sheet) about the four arms of this study. 
When women are eligible to participate after delivery, informed consent will be obtained (see 
Appendix 2 Informed Consent). 
 
All women who are planned to have an elective caesarean section will be recruited at their 
antenatal clinic appointment. A detailed patient information sheet specific for the caesarean 
section arm of this study will be given prior to consent. Informed consent will be obtained 
antenatally. After caesarean section, confirmation of willingness to participate in this study 
will be obtained and documented directly after elective caesarean. 
 
 All patients will be assessed by telephone at baseline, 7, 14, and 30 days. The recruitment 
period will be 12 months. 
 
The inclusion criteria are: 
- 
Aged 18 or over 
- 
Delivered by caesarean section (emergency or elective),  
or vaginally, sustaining a perineal tear or episiotomy which needed to be sutured 
- 
Ability to understand the content of the patient information sheet (in English, via an 
interpreter if needed and possible) 
- 
Ability to give informed consent 
 

The exclusion criteria are: 
- 
Inability to give consent 
- 
Fetal or neonatal death or poor neonatal outcome 
- 
Obstetric anal sphincter injuries 
- 
Included in another study on postpartum infection conducted in the Obstetrics and 
Gynaecology Department 
- 
Wilson’s disease 
- 
Allergy to copper 
 
Randomisation 
After inclusion all patients will be randomised for a wound dressing or maternity pad with 
(study group) or without copper (control group). The two sets of wound dressings and pads 
will be marked “A” or “B”. Both the clinician and the patient will be blinded to the randomised 
group. Only the manufacturer will be aware of which group contains copper. 
 
Copper impregnated dressings 
As soon as possible, but within 12 hours after primary closure of the caesarean section 
incision, the randomised study dressing will be applied.  The two study dressings will be 
equivalent to the dressing normally used within this Trust, except that one set of dressings 
will have a thin top layer of non-woven polyester fibres with 3% copper oxide ions 
permanently attached to it. According to local protocol the wound dressing will be left intact 
for 7 days following surgery and will be renewed if necessary. 
 
Copper impregnated maternity pads 
As soon as possible, but within 12 hours after suturing women will be asked to wear the 
study maternity pads, which will be provided. The two sets of study maternity pads will be 
equivalent to the currently recommended pads, except that one set of pads will have a thin 

top layer of non-woven polyester fibres with 3% copper oxide ions permanently attached to 
it. Women will be asked to use the pads for 14 days after delivery. 
 
Patient data, history and physical examination: 
Demographic data such as age, ethnicity, height and weight will be collected as well as 
obstetric data and delivery details (Appendix 4 Datasheet). Past medical history such as 
concomitant (chronic) diseases and the use of medications will be obtained. Wound infection 
will be assessed via a telephone questionnaire after 7, 14 and 30 days after delivery. 
The data will be stored in a secure room within Trust facilities. All electronic data will be 
stored within password protected IT system within the Trust, which is only accessible by the 
clinical and research team. 
 
Questionnaire 
For the assessment of surgical site infection, the Post Discharge Questionnaire (see 
Appendix 5 Post Discharge Questionnaire) used by the HPC surgical site infection 
surveillance will be used, which is according to the worldwide used definition of surgical site 
infection by the CDC (10). Since the Post Discharge Questionnaire is dependent on the 
women’s report rather than confirmation following clinical assessment of the wound, the 
criteria for infection have modified to allow for easy interpretation of the reported symptoms 
as follows:  
- 
Criterion 1: discharge pus AND antibiotics prescribed 
- 
Criterion 2: clinical signs* AND dehiscence 
- 
Criterion 3: Clinical signs* AND antibiotics prescribed 
*clinical signs: at least 2 of the following must be present: pain, heat, redness or 
swelling 
Without clinical assessment of the wound, the type of SSI cannot be defined. 

Since there is no commonly used definition in the literature for wound infection following 
perineal tears, the Post discharge Questionnaire with the modified criteria for infection will be 
used for the perineal tears as well. 
 
Microbiological assessment 
When wound infection is suspected according to the above explained criteria, a wound swab 
is taken to detect the causative organisms. 
  
Statistical analysis 
Statistical analysis will be performed using SPSS version 20.0 or higher. Infection rates in 
the perineal tear group and the caesarean section group will be analysed. The infection rates 
in the study group (with copper) will be compared to the control group and possible risk 
factors for infection will be explored. 
 
Sample size calculation 
Since the effect of copper on infection rates is currently unknown, we will conduct a pilot 
study for 12 months. After 3 months we will perform an interim analysis to be able to 
calculate the sample size.  
Maternity statistics at Croydon University Hospital 
 
Past 12 months 
(N=3752) 
Vaginal deliveries (N=2734) 
Episiotomy 
643 
2nd degree tear 
1334 
Total sutured tears 
(excl 3rd/4th degree tears) 
1977 
Caesarean Section (N=1018) 
EmCS 
696 
ElCS 
322 
 
Total study population 
2995 

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